Search Results

Search found 14011 results on 561 pages for 'interface orientation'.

Page 106/561 | < Previous Page | 102 103 104 105 106 107 108 109 110 111 112 113  | Next Page >

  • User Account Disabled After Upgrade to 12.04.1 LTS

    - by Five
    I upgraded from 10.xxx to 12.04.1 LTS using the upgrade feature within Ubuntu. System upgraded but after a reboot, the graphical interface comes up. When I try logging in using a user account that pre-existed on the system, the graphical interface screen disappears, screen goes blank and then reverts to the graphical interface prompting for a password. I have loads of data and installed programs under the particular user account. PLEASE HELP....

    Read the article

  • Multiple Document Interfaces in Visual Basic

    What is Multiple Document Interface (MDI)? In most VB.NET applications, it is using a single document interface (SDI). In this type of interface, every window is unique to aother window. But in multiple document interface, it works by having one parent window with child windows under it. See the screenshot below: As you can see, there is one parent window (in gray color) and there are 3 child windows (in blue, violet and orange color). You can have more than 3 child windows depending on your application requirements. But you can only have one parent window. Depending on the design of your MDI...

    Read the article

  • After some wired flash out, I can't login to wmii any more, how to fix it?

    - by Zen
    I've been using wmii on Ubuntu14.04(virtual machine on win7) for months. During which, I got pop out to login interface servaral times due to some wired mouse click action. But today, after I met such wired pop out, I can't login to wmii any more. I'll be stuck at the interface like The bottom yellow bar is the command area for wmii. but it has no response when I press Mod + p I restart my machine, and even reinstalled wmii, but everytime when I tried to login wmii, I stuck at that interface. By the way, I login to wmii from the login interface, where I can choose between Gnome and wmii. How to fix this? I'm crying for help! ps: I can login to gnome normally

    Read the article

  • Are there legitimate reasons for returning exception objects instead of throwing them?

    - by stakx
    This question is intended to apply to any OO programming language that supports exception handling; I am using C# for illustrative purposes only. Exceptions are usually intended to be raised when an problem arises that the code cannot immediately handle, and then to be caught in a catch clause in a different location (usually an outer stack frame). Q: Are there any legitimate situations where exceptions are not thrown and caught, but simply returned from a method and then passed around as error objects? This question came up for me because .NET 4's System.IObserver<T>.OnError method suggests just that: exceptions being passed around as error objects. Let's look at another scenario, validation. Let's say I am following conventional wisdom, and that I am therefore distinguishing between an error object type IValidationError and a separate exception type ValidationException that is used to report unexpected errors: partial interface IValidationError { } abstract partial class ValidationException : System.Exception { public abstract IValidationError[] ValidationErrors { get; } } (The System.Component.DataAnnotations namespace does something quite similar.) These types could be employed as follows: partial interface IFoo { } // an immutable type partial interface IFooBuilder // mutable counterpart to prepare instances of above type { bool IsValid(out IValidationError[] validationErrors); // true if no validation error occurs IFoo Build(); // throws ValidationException if !IsValid(…) } Now I am wondering, could I not simplify the above to this: partial class ValidationError : System.Exception { } // = IValidationError + ValidationException partial interface IFoo { } // (unchanged) partial interface IFooBuilder { bool IsValid(out ValidationError[] validationErrors); IFoo Build(); // may throw ValidationError or sth. like AggregateException<ValidationError> } Q: What are the advantages and disadvantages of these two differing approaches?

    Read the article

  • Mozilla interrompt le projet Electrolysis d'un Firefox multi-processus, une première version de Fennec à UI native sans XUL est disponible

    Mozilla interrompt le projet Electrolysis d'un Firefox multiprocessus Une première version de Firefox Mobile à UI native sans XUL est disponible Pour de meilleures performances et compétitivité, Mozilla avait annoncé l'abandon de la technologie d'interface XUL sur Firefox Mobile. Une décision concrétisée aujourd'hui par la sortie d'une version à interface native sur le canal Nightly. Des widgets constituent les différents composants de la nouvelle interface (barre d'adresse, contenu, futures exten...

    Read the article

  • CI tests to enforce specific development rules - good practice?

    - by KeithS
    The following is all purely hypothetical and any particular portion of it may or may not accurately describe real persons or situations, whether living, dead or just pretending. Let's say I'm a senior dev or architect in charge of a dev team working on a project. This project includes a security library for user authentication/authorization of the application under development. The library must be available for developers to edit; however, I wish to "trust but verify" that coders are not doing things that could compromise the security of the finished system, and because this isn't my only responsibility I want it to be done in an automated way. As one example, let's say I have an interface that represents a user which has been authenticated by the system's security library. The interface exposes basic user info and a list of things the user is authorized to do (so that the client app doesn't have to keep asking the server "can I do this?"), all in an immutable fashion of course. There is only one implementation of this interface in production code, and for the purposes of this post we can say that all appropriate measures have been taken to ensure that this implementation can only be used by the one part of our code that needs to be able to create concretions of the interface. The coders have been instructed that this interface and its implementation are sacrosanct and any changes must go through me. However, those are just words; the security library's source is open for editing by necessity. Any of my devs could decide that this secured, private, hash-checked implementation needs to be public so that they could do X, or alternately they could create their own implementation of this public interface in a different library, exposing the hashing algorithm that provides the secure checksum, in order to do Y. I may not be made aware of these changes so that I can beat the developer over the head for it. An attacker could then find these little nuggets in an unobfuscated library of the compiled product, and exploit it to provide fake users and/or falsely-elevated administrative permissions, bypassing the entire security system. This possibility keeps me awake for a couple of nights, and then I create an automated test that reflectively checks the codebase for types deriving from the interface, and fails if it finds any that are not exactly what and where I expect them to be. I compile this test into a project under a separate folder of the VCS that only I have rights to commit to, have CI compile it as an external library of the main project, and set it up to run as part of the CI test suite for user commits. Now, I have an automated test under my complete control that will tell me (and everyone else) if the number of implementations increases without my involvement, or an implementation that I did know about has anything new added or has its modifiers or those of its members changed. I can then investigate further, and regain the opportunity to beat developers over the head as necessary. Is this considered "reasonable" to want to do in situations like this? Am I going to be seen in a negative light for going behind my devs' backs to ensure they aren't doing something they shouldn't?

    Read the article

  • bat file to disable ethernet adaptor and then reenable it after windows log in

    - by jaslr
    When I log into Windows 7 I need to wait 10 seconds and then disable the Local Area Connection (ethernet adaptor) and then reenable it. I have looked through the suggested answer: Enable/disable wireless interface in a bat file but that seems irrelevant as it just toggles the current state. From what I can tell I need to include: netsh interface set interface "Local Area Connection" DISABLED netsh interface set interface "Local Area Connection" ENABLED but I'm unsure of the wait time or how I can have this start after Windows has successfully logged in. What's the best approach here?

    Read the article

  • Who extends interfaces? And why?

    - by Gangnus
    AFAIK, my class extends parent classes and implements interfaces. But I run across a situation, where I can't use implements SomeInterface. It is the declaration of a generic types. For example: public interface CallsForGrow {...} public class GrowingArrayList <T implements CallsForGrow> // BAD, won't work! extends ArrayList<T> Here using implements is syntactically forbidden. I thought first, that using interface inside < is forbidden at all, but no. It is possible, I only have to use extends instead of implements. As a result, I am "extending" an interface. This another example works: public interface CallsForGrow {...} public class GrowingArrayList <T extends CallsForGrow> // this works! extends ArrayList<T> To me it seems as a syntactical inconsistancy. But maybe I don't understand some finesses of Java 6? Are there other places where I should extend interfaces? Should the interface, that I mean to extend, have some special features?

    Read the article

  • Observer Pattern Implementation

    - by user17028
    To teach myself basic game programming, I am going to program a clone of Pong. I will use the Observer design pattern, with an interface between the input and the game engine. However, I'm not sure what the interface should do. One idea I had was for the input interface to tell the game engine that (e.g.) the screen was clicked, then to let the game engine decide what to do with that information (shoot a bullet, for example). Another idea I had was for the input interface, having caught the mouse click, to tell the game engine to shoot a bullet. Which method would be better for me to use?

    Read the article

  • ASP.NET MVC 2.0 User Interfaces

    The next part to this article series on MVC 2.0 is the user interface. We saw in the last article some basics on the changes of the user interface, which we'll delve into more in this article series. Here we will begin to look at how developers can construct the view user interface.

    Read the article

  • EasyHook Windows Hooking problem/.dll injection

    - by Tom
    Ok can someone try and find the error with this code, it should produce all the registry keys every time something accesses them but i keep getting: System.MissingMethodException: The given method does not exist at EasyHook.LocalHook.GetProcAdress(String InModule, String InChannelName) An example code can be found here: http://www.codeproject.com/KB/DLL/EasyHook64.aspx I can get the CcreateFileW example to work! My code is here: public class Main : EasyHook.IEntryPoint { FileMon.FileMonInterface Interface; LocalHook LocalHook; Stack<String> Queue = new Stack<String>(); public Main(RemoteHooking.IContext InContext,String InChannelName) { // connect to host... Interface = RemoteHooking.IpcConnectClient<FileMon.FileMonInterface>(InChannelName); Interface.Ping(); } public void Run(RemoteHooking.IContext InContext,String InChannelName) { // install hook... try { LocalHook localHook = LocalHook.Create(LocalHook.GetProcAddress("Advapi32.dll", "RegOpenKeyExW"),new DMyRegOpenKeyExW(MyRegOpenKeyExW),this); localHook.ThreadACL.SetExclusiveACL(new int[] { }); } catch (Exception ExtInfo) { Interface.ReportException(ExtInfo); return; } Interface.IsInstalled(RemoteHooking.GetCurrentProcessId()); RemoteHooking.WakeUpProcess(); // wait for host process termination... try { while (true) { Thread.Sleep(500); // transmit newly monitored file accesses... if (Queue.Count > 0) { String[] Package = null; lock (Queue) { Package = Queue.ToArray(); Queue.Clear(); } Interface.OnCreateFile(RemoteHooking.GetCurrentProcessId(), Package); } else Interface.Ping(); } } catch { // Ping() will raise an exception if host is unreachable } } [DllImport("Advapi32.dll", CharSet = CharSet.Unicode, SetLastError = true, CallingConvention = CallingConvention.StdCall)] static extern int RegOpenKeyExW(UIntPtr hKey,string subKey,int ulOptions,int samDesired,out UIntPtr hkResult); [UnmanagedFunctionPointer(CallingConvention.StdCall, CharSet = CharSet.Unicode, SetLastError = true)] delegate int DMyRegOpenKeyExW(UIntPtr hKey,string subKey,int ulOptions,int samDesired,out UIntPtr hkResult); int MyRegOpenKeyExW(UIntPtr hKey,string subKey,int ulOptions,int samDesired,out UIntPtr hkResult) { Console.WriteLine(string.Format("Accessing: {0}", subKey)); return RegOpenKeyExW(hKey, subKey, ulOptions, samDesired, out hkResult); } }

    Read the article

  • Is there a pattern for initializing objects created wth a DI container

    - by Igor Zevaka
    I am trying to get Unity to manage the creation of my objects and I want to have some initialization parameters that are not known until run-time: At the moment the only way I could think of the way to do it is to have an Init method on the interface. interface IMyIntf { void Initialize(string runTimeParam); string RunTimeParam { get; } } Then to use it (in Unity) I would do this: var IMyIntf = unityContainer.Resolve<IMyIntf>(); IMyIntf.Initialize("somevalue"); In this scenario runTimeParam param is determined at run-time based on user input. The trivial case here simply returns the value of runTimeParam but in reality the parameter will be something like file name and initialize method will do something with the file. This creates a number of issues, namely that the Initialize method is available on the interface and can be called multiple times. Setting a flag in the implementation and throwing exception on repeated call to Initialize seems way clunky. At the point where I resolve my interface I don't want to know anything about the implementation of IMyIntf. What I do want, though, is the knowledge that this interface needs certain one time initialization parameters. Is there a way to somehow annotate(attributes?) the interface with this information and pass those to framework when the object is created? Edit: Described the interface a bit more.

    Read the article

  • IPMI not fucntioning with Network Bonding

    - by muhammed sameer
    Hey, I am having problems with running IPMI on my servers that have network bonding enabled. Platform: CentOS release 5.3 (Final) Kernel: 2.6.18-92.el5 64bit Dell PowerEdge 1950 Ethernet controller: Broadcom Corporation NetXtreme II BCM5708 Gigabit Ethernet I have bonded the interface eth0 and eth1 as active passive, with eth0 as the active interface, below is conf description from /proc Bonding Mode: fault-tolerance (active-backup) Primary Slave: eth0 Currently Active Slave: eth0 MII Status: up MII Polling Interval (ms): 30 Up Delay (ms): 0 Down Delay (ms): 0 Slave Interface: eth0 MII Status: up Link Failure Count: 0 Permanent HW addr: 00:22:19:56:b9:cd Slave Interface: eth1 MII Status: up Link Failure Count: 0 Permanent HW addr: 00:22:19:56:b9:cf My IPMI device is as follows IPMI Device Information Interface Type: KCS (Keyboard Control Style) Specification Version: 2.0 I2C Slave Address: 0x10 NV Storage Device: Not Present Base Address: 0x0000000000000CA8 (I/O) Register Spacing: 32-bit Boundaries I Have used openIPMI as well as freeipmi both to control the chassis via the IPMI card, but on servers which have bonding enabled, the command times out, below is the full run of the command with debug info. ipmi_lan_send_cmd:opened=[0], open=[4482848] IPMI LAN host 70.87.28.115 port 623 Sending IPMI/RMCP presence ping packet ipmi_lan_send_cmd:opened=[1], open=[4482848] No response from remote controller Get Auth Capabilities command failed ipmi_lan_send_cmd:opened=[1], open=[4482848] No response from remote controller Get Auth Capabilities command failed Error: Unable to establish LAN session Failed to open LAN interface Unable to get Chassis Power Status On the other hand I configured IPMI on a box with the same specs as mentioned above without bonding and IPMI works perfectly. Has anyone faced this problem with IPMI + Bonding ? I would be thankful is someone helps circumvent this issue. Muhammed Sameer

    Read the article

  • Fortinet: Is there any equivalent of the ASA's packet-tracer command?

    - by Kedare
    I would like to know if there is not Fortigates an equivalent of the packet-tracer command that we can find on the ASA. Here is an example of execution for those who don't know it: NAT and pass : lev5505# packet-tracer input inside tcp 192.168.3.20 9876 8.8.8.8 80 Phase: 1 Type: ACCESS-LIST Subtype: Result: ALLOW Config: Implicit Rule Additional Information: MAC Access list Phase: 2 Type: ROUTE-LOOKUP Subtype: input Result: ALLOW Config: Additional Information: in 0.0.0.0 0.0.0.0 outside Phase: 3 Type: ACCESS-LIST Subtype: log Result: ALLOW Config: access-group inside-in in interface inside access-list inside-in extended permit tcp any any eq www access-list inside-in remark Allows DNS Additional Information: Phase: 4 Type: IP-OPTIONS Subtype: Result: ALLOW Config: Additional Information: Phase: 5 Type: VPN Subtype: ipsec-tunnel-flow Result: ALLOW Config: Additional Information: Phase: 6 Type: NAT Subtype: Result: ALLOW Config: object network inside-network nat (inside,outside) dynamic interface Additional Information: Dynamic translate 192.168.3.20/9876 to 81.56.15.183/9876 Phase: 7 Type: IP-OPTIONS Subtype: Result: ALLOW Config: Additional Information: Phase: 8 Type: FLOW-CREATION Subtype: Result: ALLOW Config: Additional Information: New flow created with id 94755, packet dispatched to next module Result: input-interface: inside input-status: up input-line-status: up output-interface: outside output-status: up output-line-status: up Action: allow Blocked by ACL: lev5505# packet-tracer input inside tcp 192.168.3.20 9876 8.8.8.8 81 Phase: 1 Type: ROUTE-LOOKUP Subtype: input Result: ALLOW Config: Additional Information: in 0.0.0.0 0.0.0.0 outside Phase: 2 Type: ACCESS-LIST Subtype: Result: DROP Config: Implicit Rule Additional Information: Result: input-interface: inside input-status: up input-line-status: up output-interface: outside output-status: up output-line-status: up Action: drop Drop-reason: (acl-drop) Flow is denied by configured rule Is there any equivalent on the Fortigates ?

    Read the article

  • Force netsh/arp binding multicast IP addres with specific MAC address

    - by Olivier
    I would like to setup an binding from an IP address to a MAC address using netsh. Goal is to bond an IP address which is a multicast address (224.224.x.y) to a given MAC address (which is NOT the calculated one from the multicast IP address : 01:00:5e:X:Y:Z It used to work with Windows XP (was it a bug that used to be "perfect" for my needs?), but Windows 7/8/8.1 forces the MAC address to the calculated one instead of letting me put what I want! (http://nettools.aqwnet.com/ipmaccalc/ipmaccalc.php shows MAC address calculation for multicast IP address) Thus I'm doing the following. Listing existing mappings: netsh.exe interface ip show neighbors "Ethernet" Interface 12 : Ethernet Internet address Physical address Type 224.0.0.22 01-00-5e-XX-YY-ZZ static Then adding my interface mapping manually: netsh.exe interface ip add neighbors "Ethernet" "224.xxx.yyy.zzz" "00-80-EE-UU-VV-WW" Finally, listing again my mappings: netsh.exe interface ip show neighbors "Ethernet" Interface 12 : Ethernet Internet address Physical address Type 224.0.0.22 01-00-5e-XX-YY-ZZ static **224.xxx.yyy.zzz 01-00-5e-UU-VV-WW static** As you can see, the MAC Address of the second entry (the one I just made) has been dynamically replaced by the calculated MAC Address corresponding to my IP Address... Calculation is done as follow (and displayed in hexa): UU=(xxx-128) VV=yyy WW=zzz But I don't want that behavior. My IP address and MAC address cannot be changed, and I must associate them accurately. Does anybody know how to disable MAC address substitution/calculation in netsh? Thanks, Olivier.

    Read the article

  • VMware virtual machine network devices malfunctioning

    - by sheepz
    I'm running Ubuntu 10.04 LTS and VMvware workstation 7.0.1 build-227600. The virtual machine i'm running in VMware is a custom distribution built on Debian Linux version 3.1. I'm still pretty much a beginner with UNIX administration. After having messed around with the vmware (changed only the name of the folder, the vmx and and other .v* files accordingly in which the .vmx was situated, and the configuration in the vmx file accordingly), the network devices on the virtual machine do not work anymore. The virtual machine is used for securely sending messages. The virtual machine: As far as I know, this perl file called proxy-gen-ifalias eth0 is responsible for properly setting up the two virtual network devices eth0 and eth1. The Virtual machine comes with a GUI interface in which I have set up two ethernet network devices, one internal, the other external. Now, after having messed around with this, the UI gives me this error message: perl proxy-gen-ifalias eth0 /etc/modprobe.d/alias-eth0 /sbin/update-modules perl proxy-gen-ifalias eth1 /etc/modprobe.d/alias-eth1 /sbin/update-modules ifdown eth0 ifdown: interface eth0 not configured ifdown eth1 ifdown: interface eth1 not configured perl proxy-gen-netcfg /etc/network/interfaces ifup eth0 SICCSIFADDR: No such device eth0: ERROR while getting interface flags: No such device SIOCSIFNETMASK: No such device eth0: ERROR while getting interface flags: No such device Failed to bring up eth0. ifconfig eth0 eth0: error fetching interface information: Device not found make: *** [/etc/network/interfaces] Error 1 ~ Here are the contents of the two perl files referred to in the message: paste.pocoo.org/show/2AMzAYhoCRZqlGY7wUFk/ proxy-gen-netcfg

    Read the article

  • OpenVPN Client timing out

    - by Austin
    I recently installed OpenVPN on my Ubuntu VPS. Whenenver I try to connect to it, I can establish a connection just fine. However, everything I try to connect to times out. If I try to ping something, it will resolve the IP, but will time out after resolving the IP. (So DNS Server seems to be working correctly) My server.conf has this relevant information (At least I think it's relevant. I'm not sure if you need more or not) # Which local IP address should OpenVPN # listen on? (optional) ;local a.b.c.d # Which TCP/UDP port should OpenVPN listen on? # If you want to run multiple OpenVPN instances # on the same machine, use a different port # number for each one. You will need to # open up this port on your firewall. port 1194 # TCP or UDP server? ;proto tcp proto udp # "dev tun" will create a routed IP tunnel, # "dev tap" will create an ethernet tunnel. # Use "dev tap0" if you are ethernet bridging # and have precreated a tap0 virtual interface # and bridged it with your ethernet interface. # If you want to control access policies # over the VPN, you must create firewall # rules for the the TUN/TAP interface. # On non-Windows systems, you can give # an explicit unit number, such as tun0. # On Windows, use "dev-node" for this. # On most systems, the VPN will not function # unless you partially or fully disable # the firewall for the TUN/TAP interface. ;dev tap dev tun # Windows needs the TAP-Win32 adapter name # from the Network Connections panel if you # have more than one. On XP SP2 or higher, # you may need to selectively disable the # Windows firewall for the TAP adapter. # Non-Windows systems usually don't need this. ;dev-node MyTap # SSL/TLS root certificate (ca), certificate # (cert), and private key (key). Each client # and the server must have their own cert and # key file. The server and all clients will # use the same ca file. # # See the "easy-rsa" directory for a series # of scripts for generating RSA certificates # and private keys. Remember to use # a unique Common Name for the server # and each of the client certificates. # # Any X509 key management system can be used. # OpenVPN can also use a PKCS #12 formatted key file # (see "pkcs12" directive in man page). ca ca.crt cert server.crt key server.key # This file should be kept secret # Diffie hellman parameters. # Generate your own with: # openssl dhparam -out dh1024.pem 1024 # Substitute 2048 for 1024 if you are using # 2048 bit keys. dh dh1024.pem # Configure server mode and supply a VPN subnet # for OpenVPN to draw client addresses from. # The server will take 10.8.0.1 for itself, # the rest will be made available to clients. # Each client will be able to reach the server # on 10.8.0.1. Comment this line out if you are # ethernet bridging. See the man page for more info. server 10.8.0.0 255.255.255.0 # Maintain a record of client <-> virtual IP address # associations in this file. If OpenVPN goes down or # is restarted, reconnecting clients can be assigned # the same virtual IP address from the pool that was # previously assigned. ifconfig-pool-persist ipp.txt # Configure server mode for ethernet bridging. # You must first use your OS's bridging capability # to bridge the TAP interface with the ethernet # NIC interface. Then you must manually set the # IP/netmask on the bridge interface, here we # assume 10.8.0.4/255.255.255.0. Finally we # must set aside an IP range in this subnet # (start=10.8.0.50 end=10.8.0.100) to allocate # to connecting clients. Leave this line commented # out unless you are ethernet bridging. ;server-bridge 10.8.0.4 255.255.255.0 10.8.0.50 10.8.0.100 # Configure server mode for ethernet bridging # using a DHCP-proxy, where clients talk # to the OpenVPN server-side DHCP server # to receive their IP address allocation # and DNS server addresses. You must first use # your OS's bridging capability to bridge the TAP # interface with the ethernet NIC interface. # Note: this mode only works on clients (such as # Windows), where the client-side TAP adapter is # bound to a DHCP client. ;server-bridge # Push routes to the client to allow it # to reach other private subnets behind # the server. Remember that these # private subnets will also need # to know to route the OpenVPN client # address pool (10.8.0.0/255.255.255.0) # back to the OpenVPN server. ;push "route 192.168.10.0 255.255.255.0" ;push "route 192.168.20.0 255.255.255.0" # To assign specific IP addresses to specific # clients or if a connecting client has a private # subnet behind it that should also have VPN access, # use the subdirectory "ccd" for client-specific # configuration files (see man page for more info). # EXAMPLE: Suppose the client # having the certificate common name "Thelonious" # also has a small subnet behind his connecting # machine, such as 192.168.40.128/255.255.255.248. # First, uncomment out these lines: ;client-config-dir ccd ;route 192.168.40.128 255.255.255.248 # Then create a file ccd/Thelonious with this line: # iroute 192.168.40.128 255.255.255.248 # This will allow Thelonious' private subnet to # access the VPN. This example will only work # if you are routing, not bridging, i.e. you are # using "dev tun" and "server" directives. # EXAMPLE: Suppose you want to give # Thelonious a fixed VPN IP address of 10.9.0.1. # First uncomment out these lines: ;client-config-dir ccd ;route 10.9.0.0 255.255.255.252 # Then add this line to ccd/Thelonious: # ifconfig-push 10.9.0.1 10.9.0.2 # Suppose that you want to enable different # firewall access policies for different groups # of clients. There are two methods: # (1) Run multiple OpenVPN daemons, one for each # group, and firewall the TUN/TAP interface # for each group/daemon appropriately. # (2) (Advanced) Create a script to dynamically # modify the firewall in response to access # from different clients. See man # page for more info on learn-address script. ;learn-address ./script # If enabled, this directive will configure # all clients to redirect their default # network gateway through the VPN, causing # all IP traffic such as web browsing and # and DNS lookups to go through the VPN # (The OpenVPN server machine may need to NAT # or bridge the TUN/TAP interface to the internet # in order for this to work properly). push "redirect-gateway def1 bypass-dhcp" push "dhcp-option DNS 8.8.8.8" # Certain Windows-specific network settings # can be pushed to clients, such as DNS # or WINS server addresses. CAVEAT: # http://openvpn.net/faq.html#dhcpcaveats # The addresses below refer to the public # DNS servers provided by opendns.com. ;push "dhcp-option DNS 8.8.8.8" push "dhcp-option DNS 8.8.4.4" # Uncomment this directive to allow different # clients to be able to "see" each other. # By default, clients will only see the server. # To force clients to only see the server, you # will also need to appropriately firewall the # server's TUN/TAP interface. ;client-to-client # Uncomment this directive if multiple clients # might connect with the same certificate/key # files or common names. This is recommended # only for testing purposes. For production use, # each client should have its own certificate/key # pair. # # IF YOU HAVE NOT GENERATED INDIVIDUAL # CERTIFICATE/KEY PAIRS FOR EACH CLIENT, # EACH HAVING ITS OWN UNIQUE "COMMON NAME", # UNCOMMENT THIS LINE OUT. ;duplicate-cn # The keepalive directive causes ping-like # messages to be sent back and forth over # the link so that each side knows when # the other side has gone down. # Ping every 10 seconds, assume that remote # peer is down if no ping received during # a 120 second time period. keepalive 10 120 # For extra security beyond that provided # by SSL/TLS, create an "HMAC firewall" # to help block DoS attacks and UDP port flooding. # # Generate with: # openvpn --genkey --secret ta.key # # The server and each client must have # a copy of this key. # The second parameter should be '0' # on the server and '1' on the clients. ;tls-auth ta.key 0 # This file is secret # Select a cryptographic cipher. # This config item must be copied to # the client config file as well. ;cipher BF-CBC # Blowfish (default) ;cipher AES-128-CBC # AES ;cipher DES-EDE3-CBC # Triple-DES # Enable compression on the VPN link. # If you enable it here, you must also # enable it in the client config file. comp-lzo # The maximum number of concurrently connected # clients we want to allow. ;max-clients 100 # It's a good idea to reduce the OpenVPN # daemon's privileges after initialization. # # You can uncomment this out on # non-Windows systems. ;user nobody ;group nogroup # The persist options will try to avoid # accessing certain resources on restart # that may no longer be accessible because # of the privilege downgrade. persist-key persist-tun # Output a short status file showing # current connections, truncated # and rewritten every minute. status openvpn-status.log # By default, log messages will go to the syslog (or # on Windows, if running as a service, they will go to # the "\Program Files\OpenVPN\log" directory). # Use log or log-append to override this default. # "log" will truncate the log file on OpenVPN startup, # while "log-append" will append to it. Use one # or the other (but not both). ;log openvpn.log ;log-append openvpn.log # Set the appropriate level of log # file verbosity. # # 0 is silent, except for fatal errors # 4 is reasonable for general usage # 5 and 6 can help to debug connection problems # 9 is extremely verbose verb 3 # Silence repeating messages. At most 20 # sequential messages of the same message # category will be output to the log. ;mute 20 I've tried on multiple computers by the way. The same result on all of them. What could be wrong? Thanks in advance, and if you need other information I'll gladly post it. Information for new comments root@vps:~# iptables -L -n -v Chain INPUT (policy ACCEPT 862K packets, 51M bytes) pkts bytes target prot opt in out source destination Chain FORWARD (policy ACCEPT 3 packets, 382 bytes) pkts bytes target prot opt in out source destination 0 0 ACCEPT all -- * * 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED 4641 298K ACCEPT all -- * * 10.8.0.0/24 0.0.0.0/0 0 0 REJECT all -- * * 0.0.0.0/0 0.0.0.0/0 reject-with icmp-port-unreachable Chain OUTPUT (policy ACCEPT 1671K packets, 2378M bytes) pkts bytes target prot opt in out source destination And root@vps:~# iptables -t nat -L -n -v Chain PREROUTING (policy ACCEPT 17937 packets, 2013K bytes) pkts bytes target prot opt in out source destination Chain POSTROUTING (policy ACCEPT 8975 packets, 562K bytes) pkts bytes target prot opt in out source destination 1579 103K SNAT all -- * * 10.8.0.0/24 0.0.0.0/0 to:SERVERIP Chain OUTPUT (policy ACCEPT 8972 packets, 562K bytes) pkts bytes target prot opt in out source destination

    Read the article

  • Configuring https access on HP A5120 Switch

    - by GerryEgan
    I am trying to configure HTTPS management on a HP a5120 switch running Version 5.20.99, Release 2215 and not having much luck. I have followed the manual by creating an SSL policy first and then enabling the HTTPS server with the SSL policy: ssl server-policy sslpol ip https ssl-server-policy sslpol ip https enable When I try and log onto the switch with Google Chrome I get the following error: Error 107 (net::ERR_SSL_PROTOCOL_ERROR): SSL protocol error. When I look this up I have found references to errors due to TLS being used in SSL. I can find no way to specify the SSL version in the server policy. The manual has a configuration example that uses MSCEP to retrieve a certificate but in Windows 2008 R2 that feature is only available in Enterprise and Datacentre editions which I don't have. I have SSH configured and it is using a locally generated certificate so I'm not sure if I can use that but I'd like to if possible. Has anybody been able to setup HTTPS management on HP A series switches without MSCEP? Any and all help appreciated! here is a copy of my config with the interfaces removed: version 5.20.99, Release 2215 # sysname MYSYSNAME # irf domain 10 irf mac-address persistent timer irf auto-update enable undo irf link-delay # domain default enable system # telnet server enable # vlan 1 # vlan 100 description Management # radius scheme system primary authentication 127.0.0.1 1645 primary accounting 127.0.0.1 1646 user-name-format without-domain # domain system access-limit disable state active idle-cut disable self-service-url disable # user-group system group-attribute allow-guest # local-user admin password cipher authorization-attribute level 3 service-type ssh telnet terminal service-type web # stp enable # ssl server-policy sslpol pki-domain MYDOMAIN # interface NULL0 # interface Vlan-interface199 ip address 192.168.199.140 255.255.255.0 # interface GigabitEthernet1/0/1 poe enable stp edged-port enable # interface Ten-GigabitEthernet2/1/2 # dhcp-snooping # ntp-service unicast-server 192.168.1.71 # ssh server enable # ip https ssl-server-policy sslpol ip https enable # load xml-configuration # user-interface aux 0 1 user-interface vty 0 15 authentication-mode scheme

    Read the article

  • Assistance on setup to Connect an offsite server to the LAN via RRAS VPN - Server 2008 R2

    - by Paul D'Ambra
    I have an office LAN protected using a Zyxel Zywall USG 300. I've set up an L2TP/ipsec VPN on that which accepts connections using a shared secret and I've tested this from multiple clients. I have a server offsite and want to set up RRAS to use a persistent connection to the VPN so that it can carry out network jobs even with no one logged in (I'm using it for Micorosft DPM secondary backup). If I create a vpn as if I were setting up a users laptop it can dial in no problem but if I set up a demand dial interface in RRAS it errors. I enable RRAS ticking only demand dial interface (branch office routing) Select network interfaces, right click and choose new demand dial interface Name the VPN ToCompany Select connect using VPN And then L2TP as the vpn type enter the IP address (double-checked for typos!) select Route IP packets on this interface specify static route to remote network as 10.0.0.0/24 with metric of 1 add dial out credentials (again double checked for typos and confirmed with other vpn connections click finish now I right-click on the new interface and choose properties and then the security tab I change Data encryption to optional select only PAP for Authentication (both as per manufacturer of Zywall) click advanced settings against type of vpn and set shared secret then I select the new interface, right-click and choose connect this dials and then errors with either 720 or 811 as the error codes. However, if I create a VPN by going to Network & Sharing center and setting up as if I was creating a VPN from my laptop to the office (say) it dials successfully so I know the VPN settings are correct and the machine can connect to the VPN. Suggests very strongly the problem is how I'm setting up RRAS. Can anyone help?

    Read the article

  • NAT confusion regarding cisco ASA5510

    - by LonelyLonelyNetworkN00b
    I'm setting up my first cisco firewalls. A little information first:I have two asa5510 setup in a working active/standby pair. From my ISP i have two public subnets. A /29 and a /26. On my DMZ interface i have the /26 configured. On my WAN Interface i have configured the /29 IPs. My isp routes the /26 via the /29 primary IP. I'm running ASA 8.2. I've turned NAT-Control off, because i don't want to use nat for for other than some internal interfaces. In essence i don't want to use NAT unless i specify it. I have a internal interface with the network of 192.168.100.0/24. I've tried setting up nat limke this: nat (inside) 1 192.168.100.0 255.255.255.0 global (WAN) 1 interface I was under the impression that this would let connections that was going from 192.168.100.0/24 and out the WAN interface to be Port-Address-translated. I'm not getting this to work for some reason. Inside interface has security level of 100, and wan has security level of 0.

    Read the article

  • Unable to PPTP through NAT on Cisco 881

    - by MasterRoot24
    I'm trying to connect to a PPTP server which is sat behind a Cisco 881 NAT router. The server is running Ubuntu Server 12.04 and is running Poptop pptpd as the PPTP daemon listening for connections. As discussed in my other question, I'm trying to setup a Cisco 881 router to replace my old Linksys WAG320N. This same server and WAN connection worked fine with the WAG320N with no special configuration, other than allowing 1723 in through the firewall. On the Cisco 881, I'm using the newer ip nat enable or NAT NVI to setup static routes in through the firewall for the services running behind the router. My reason being that I can't run another copy of my live DNS domains internally with local IP addresses in. For the purposes of this question, though, I have rebuilt the router with ip nat inside/outside style NAT'ing, but this issue is still apparent. HTTP/SMTP/IMAP etc. all work ok from both the WAN and LAN interfaces of the router. I'm only having issues with SIP (see other question) and PPTP. My issue is that the GRE doesn't appear to be passing through NAT correctly and one end of the connection is not receiving GRE traffic when it should be, so the server hangs up the connection. Here's an example of /var/log/syslog with debug enabled in /etc/pptpd.conf: Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: MGR: Launching /usr/sbin/pptpctrl to handle client Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: CTRL: local address = 192.168.1.50 Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: CTRL: remote address = 192.168.1.51 Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: CTRL: pppd options file = /etc/ppp/pptpd-options Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: CTRL: Client 82.132.248.216 control connection started Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: CTRL: Received PPTP Control Message (type: 1) Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: CTRL: Made a START CTRL CONN RPLY packet Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: CTRL: I wrote 156 bytes to the client. Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: CTRL: Sent packet to client Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: CTRL: Received PPTP Control Message (type: 7) Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: CTRL: Set parameters to 100000000 maxbps, 64 window size Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: CTRL: Made a OUT CALL RPLY packet Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: CTRL: Starting call (launching pppd, opening GRE) Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: CTRL: pty_fd = 6 Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: CTRL: tty_fd = 7 Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: CTRL: I wrote 32 bytes to the client. Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: CTRL: Sent packet to client Dec 11 21:06:30 <HOSTNAME> pptpd[22627]: CTRL (PPPD Launcher): program binary = /usr/sbin/pppd Dec 11 21:06:30 <HOSTNAME> pptpd[22627]: CTRL (PPPD Launcher): local address = 192.168.1.50 Dec 11 21:06:30 <HOSTNAME> pptpd[22627]: CTRL (PPPD Launcher): remote address = 192.168.1.51 Dec 11 21:06:30 <HOSTNAME> pppd[22627]: Plugin /usr/lib/pptpd/pptpd-logwtmp.so loaded. Dec 11 21:06:30 <HOSTNAME> pppd[22627]: pppd 2.4.5 started by root, uid 0 Dec 11 21:06:30 <HOSTNAME> pppd[22627]: Using interface ppp0 Dec 11 21:06:30 <HOSTNAME> pppd[22627]: Connect: ppp0 <--> /dev/pts/3 Dec 11 21:06:30 <HOSTNAME> pptpd[22626]: GRE: Bad checksum from pppd. Dec 11 21:06:31 <HOSTNAME> pptpd[22626]: CTRL: Received PPTP Control Message (type: 15) Dec 11 21:06:31 <HOSTNAME> pptpd[22626]: CTRL: Got a SET LINK INFO packet with standard ACCMs Dec 11 21:07:00 <HOSTNAME> pppd[22627]: LCP: timeout sending Config-Requests Dec 11 21:07:00 <HOSTNAME> pppd[22627]: Connection terminated. Dec 11 21:07:00 <HOSTNAME> avahi-daemon[1042]: Withdrawing workstation service for ppp0. Dec 11 21:07:00 <HOSTNAME> pppd[22627]: Modem hangup Dec 11 21:07:00 <HOSTNAME> pppd[22627]: Exit. Dec 11 21:07:00 <HOSTNAME> pptpd[22626]: GRE: read(fd=6,buffer=6075a0,len=8196) from PTY failed: status = -1 error = Input/output error, usually caused by unexpected termination of pppd, check option syntax and pppd logs Dec 11 21:07:00 <HOSTNAME> pptpd[22626]: CTRL: PTY read or GRE write failed (pty,gre)=(6,7) Dec 11 21:07:00 <HOSTNAME> pptpd[22626]: CTRL: Reaping child PPP[22627] Dec 11 21:07:00 <HOSTNAME> pptpd[22626]: CTRL: Client 82.132.248.216 control connection finished Dec 11 21:07:00 <HOSTNAME> pptpd[22626]: CTRL: Exiting now Dec 11 21:07:00 <HOSTNAME> pptpd[5803]: MGR: Reaped child 22626 As far as Cisco are concerned, all I need is ip nat source static tcp <SERVER LAN IP> 1723 interface FastEthernet4 1723 but of course this doesn't seem to the be helping the GRE traffic through as it should. Trying the connection to the LAN IP of the server from the same LAN as the server (behind the router), the PPTP connection works fine, so I'm confident that the server's config is ok. Furthermore, all I needed on my WAG320N was to open 1723 in the firewall. Here's my current router config: ! ! Last configuration change at 20:20:15 UTC Tue Dec 11 2012 by xxx version 15.2 no service pad service timestamps debug datetime msec service timestamps log datetime msec service password-encryption ! hostname xxx ! boot-start-marker boot-end-marker ! ! enable secret 4 xxxx ! aaa new-model ! ! aaa authentication login local_auth local ! ! ! ! ! aaa session-id common ! memory-size iomem 10 ! crypto pki trustpoint TP-self-signed-xxx enrollment selfsigned subject-name cn=IOS-Self-Signed-Certificate-xxx revocation-check none rsakeypair TP-self-signed-xxx ! ! crypto pki certificate chain TP-self-signed-xxx certificate self-signed 01 xxx quit ip gratuitous-arps ip auth-proxy max-login-attempts 5 ip admission max-login-attempts 5 ! ! ! ! ! ip domain list dmz.xxx.local ip domain list xxx.local ip domain name dmz.xxx.local ip name-server 192.168.1.x ip cef login block-for 3 attempts 3 within 3 no ipv6 cef ! ! multilink bundle-name authenticated license udi pid CISCO881-SEC-K9 sn xxx ! ! username admin privilege 15 secret 4 xxx username joe secret 4 xxx ! ! ! ! ! ip ssh time-out 60 ! ! ! ! ! ! ! ! ! interface FastEthernet0 no ip address ! interface FastEthernet1 no ip address ! interface FastEthernet2 no ip address ! interface FastEthernet3 switchport access vlan 2 no ip address ! interface FastEthernet4 ip address dhcp ip nat enable duplex auto speed auto ! interface Vlan1 ip address 192.168.1.x 255.255.255.0 no ip redirects no ip unreachables no ip proxy-arp ip nat enable ! interface Vlan2 ip address 192.168.0.x 255.255.255.0 ! ip forward-protocol nd ip http server ip http access-class 1 ip http authentication local ip http secure-server ! ! ip nat source list 1 interface FastEthernet4 overload ip nat source list 2 interface FastEthernet4 overload ip nat source static tcp 192.168.1.x 1723 interface FastEthernet4 1723 ! ! access-list 1 permit 192.168.0.0 0.0.0.255 access-list 2 permit 192.168.1.0 0.0.0.255 ! ! ! ! control-plane ! ! banner motd Authorized Access only ! line con 0 exec-timeout 15 0 login authentication local_auth line aux 0 exec-timeout 15 0 login authentication local_auth line vty 0 4 access-class 2 in login authentication local_auth length 0 transport input all ! ! end UPDATE 16/12/2012: The only progress that I have been able to make on this issue is that I'm confident that the issue is caused by the GRE tunnels (which are required for the PPTP connection to complete) are being blocked. When attempting a connection, I can see in show ip nat nvi translations that both a TCP translation on 1723 is setup and also a GRE translation is setup also. I appear to be able to see GRE related packets on the LAN that the server is on, so I am lead to believe that the server is sending(?) GRE packets, however running Wireshark on a client PC when attempting a connection shows absolutely no GRE packets. Whilst there are no configuration directives in my config posted above (that I can pin point) which would specifically block them, it would appear that the GRE packets are not being allowed in/out of the router's firewall, even though a NAT translation entry is setup to the server's LAN address. Would anyone be able to provide me with some help to ensure that GRE packets are not blocked by the router's firewall, so that this can be ruled out as a possible issue please?

    Read the article

  • Flow-Design Cheat Sheet &ndash; Part I, Notation

    - by Ralf Westphal
    You want to avoid the pitfalls of object oriented design? Then this is the right place to start. Use Flow-Oriented Analysis (FOA) and –Design (FOD or just FD for Flow-Design) to understand a problem domain and design a software solution. Flow-Orientation as described here is related to Flow-Based Programming, Event-Based Programming, Business Process Modelling, and even Event-Driven Architectures. But even though “thinking in flows” is not new, I found it helpful to deviate from those precursors for several reasons. Some aim at too big systems for the average programmer, some are concerned with only asynchronous processing, some are even not very much concerned with programming at all. What I was looking for was a design method to help in software projects of any size, be they large or tiny, involing synchronous or asynchronous processing, being local or distributed, running on the web or on the desktop or on a smartphone. That´s why I took ideas from all of the above sources and some additional and came up with Event-Based Components which later got repositioned and renamed to Flow-Design. In the meantime this has generated some discussion (in the German developer community) and several teams have started to work with Flow-Design. Also I´ve conducted quite some trainings using Flow-Orientation for design. The results are very promising. Developers find it much easier to design software using Flow-Orientation than OOAD-based object orientation. Since Flow-Orientation is moving fast and is not covered completely by a single source like a book, demand has increased for at least an overview of the current state of its notation. This page is trying to answer this demand by briefly introducing/describing every notational element as well as their translation into C# source code. Take this as a cheat sheet to put next to your whiteboard when designing software. However, please do not expect any explanation as to the reasons behind Flow-Design elements. Details on why Flow-Design at all and why in this specific way you´ll find in the literature covering the topic. Here´s a resource page on Flow-Design/Event-Based Components, if you´re able to read German. Notation Connected Functional Units The basic element of any FOD are functional units (FU): Think of FUs as some kind of software code block processing data. For the moment forget about classes, methods, “components”, assemblies or whatever. See a FU as an abstract piece of code. Software then consists of just collaborating FUs. I´m using circles/ellipses to draw FUs. But if you like, use rectangles. Whatever suites your whiteboard needs best.   The purpose of FUs is to process input and produce output. FUs are transformational. However, FUs are not called and do not call other FUs. There is no dependency between FUs. Data just flows into a FU (input) and out of it (output). From where and where to is of no concern to a FU.   This way FUs can be concatenated in arbitrary ways:   Each FU can accept input from many sources and produce output for many sinks:   Flows Connected FUs form a flow with a start and an end. Data is entering a flow at a source, and it´s leaving it through a sink. Think of sources and sinks as special FUs which conntect wires to the environment of a network of FUs.   Wiring Details Data is flowing into/out of FUs through wires. This is to allude to electrical engineering which since long has been working with composable parts. Wires are attached to FUs usings pins. They are the entry/exit points for the data flowing along the wires. Input-/output pins currently need not be drawn explicitly. This is to keep designing on a whiteboard simple and quick.   Data flowing is of some type, so wires have a type attached to them. And pins have names. If there is only one input pin and output pin on a FU, though, you don´t need to mention them. The default is Process for a single input pin, and Result for a single output pin. But you´re free to give even single pins different names.   There is a shortcut in use to address a certain pin on a destination FU:   The type of the wire is put in parantheses for two reasons. 1. This way a “no-type” wire can be easily denoted, 2. this is a natural way to describe tuples of data.   To describe how much data is flowing, a star can be put next to the wire type:   Nesting – Boards and Parts If more than 5 to 10 FUs need to be put in a flow a FD starts to become hard to understand. To keep diagrams clutter free they can be nested. You can turn any FU into a flow: This leads to Flow-Designs with different levels of abstraction. A in the above illustration is a high level functional unit, A.1 and A.2 are lower level functional units. One of the purposes of Flow-Design is to be able to describe systems on different levels of abstraction and thus make it easier to understand them. Humans use abstraction/decomposition to get a grip on complexity. Flow-Design strives to support this and make levels of abstraction first class citizens for programming. You can read the above illustration like this: Functional units A.1 and A.2 detail what A is supposed to do. The whole of A´s responsibility is decomposed into smaller responsibilities A.1 and A.2. FU A thus does not do anything itself anymore! All A is responsible for is actually accomplished by the collaboration between A.1 and A.2. Since A now is not doing anything anymore except containing A.1 and A.2 functional units are devided into two categories: boards and parts. Boards are just containing other functional units; their sole responsibility is to wire them up. A is a board. Boards thus depend on the functional units nested within them. This dependency is not of a functional nature, though. Boards are not dependent on services provided by nested functional units. They are just concerned with their interface to be able to plug them together. Parts are the workhorses of flows. They contain the real domain logic. They actually transform input into output. However, they do not depend on other functional units. Please note the usage of source and sink in boards. They correspond to input-pins and output-pins of the board.   Implicit Dependencies Nesting functional units leads to a dependency tree. Boards depend on nested functional units, they are the inner nodes of the tree. Parts are independent, they are the leafs: Even though dependencies are the bane of software development, Flow-Design does not usually draw these dependencies. They are implicitly created by visually nesting functional units. And they are harmless. Boards are so simple in their functionality, they are little affected by changes in functional units they are depending on. But functional units are implicitly dependent on more than nested functional units. They are also dependent on the data types of the wires attached to them: This is also natural and thus does not need to be made explicit. And it pertains mainly to parts being dependent. Since boards don´t do anything with regard to a problem domain, they don´t care much about data types. Their infrastructural purpose just needs types of input/output-pins to match.   Explicit Dependencies You could say, Flow-Orientation is about tackling complexity at its root cause: that´s dependencies. “Natural” dependencies are depicted naturally, i.e. implicitly. And whereever possible dependencies are not even created. Functional units don´t know their collaborators within a flow. This is core to Flow-Orientation. That makes for high composability of functional units. A part is as independent of other functional units as a motor is from the rest of the car. And a board is as dependend on nested functional units as a motor is on a spark plug or a crank shaft. With Flow-Design software development moves closer to how hardware is constructed. Implicit dependencies are not enough, though. Sometimes explicit dependencies make designs easier – as counterintuitive this might sound. So FD notation needs a ways to denote explicit dependencies: Data flows along wires. But data does not flow along dependency relations. Instead dependency relations represent service calls. Functional unit C is depending on/calling services on functional unit S. If you want to be more specific, name the services next to the dependency relation: Although you should try to stay clear of explicit dependencies, they are fundamentally ok. See them as a way to add another dimension to a flow. Usually the functionality of the independent FU (“Customer repository” above) is orthogonal to the domain of the flow it is referenced by. If you like emphasize this by using different shapes for dependent and independent FUs like above. Such dependencies can be used to link in resources like databases or shared in-memory state. FUs can not only produce output but also can have side effects. A common pattern for using such explizit dependencies is to hook a GUI into a flow as the source and/or the sink of data: Which can be shortened to: Treat FUs others depend on as boards (with a special non-FD API the dependent part is connected to), but do not embed them in a flow in the diagram they are depended upon.   Attributes of Functional Units Creation and usage of functional units can be modified with attributes. So far the following have shown to be helpful: Singleton: FUs are by default multitons. FUs in the same of different flows with the same name refer to the same functionality, but to different instances. Think of functional units as objects that get instanciated anew whereever they appear in a design. Sometimes though it´s helpful to reuse the same instance of a functional unit; this is always due to valuable state it holds. Signify this by annotating the FU with a “(S)”. Multiton: FUs on which others depend are singletons by default. This is, because they usually are introduced where shared state comes into play. If you want to change them to be a singletons mark them with a “(M)”. Configurable: Some parts need to be configured before the can do they work in a flow. Annotate them with a “(C)” to have them initialized before any data items to be processed by them arrive. Do not assume any order in which FUs are configured. How such configuration is happening is an implementation detail. Entry point: In each design there needs to be a single part where “it all starts”. That´s the entry point for all processing. It´s like Program.Main() in C# programs. Mark the entry point part with an “(E)”. Quite often this will be the GUI part. How the entry point is started is an implementation detail. Just consider it the first FU to start do its job.   Patterns / Standard Parts If more than a single wire is attached to an output-pin that´s called a split (or fork). The same data is flowing on all of the wires. Remember: Flow-Designs are synchronous by default. So a split does not mean data is processed in parallel afterwards. Processing still happens synchronously and thus one branch after another. Do not assume any specific order of the processing on the different branches after the split.   It is common to do a split and let only parts of the original data flow on through the branches. This effectively means a map is needed after a split. This map can be implicit or explicit.   Although FUs can have multiple input-pins it is preferrable in most cases to combine input data from different branches using an explicit join: The default output of a join is a tuple of its input values. The default behavior of a join is to output a value whenever a new input is received. However, to produce its first output a join needs an input for all its input-pins. Other join behaviors can be: reset all inputs after an output only produce output if data arrives on certain input-pins

    Read the article

< Previous Page | 102 103 104 105 106 107 108 109 110 111 112 113  | Next Page >