Search Results

Search found 30220 results on 1209 pages for 'connection problems'.

Page 185/1209 | < Previous Page | 181 182 183 184 185 186 187 188 189 190 191 192  | Next Page >

• Is there a common programming term for the problems of adding features to an already-featureful program?

  - by Jeremy Friesner

  I'm looking for a commonly used programming term to describe a software-engineering phenomenon, which (for lack of a better way to describe it) I'll illustrate first with a couple of examples-by-analogy: Scenario 1: We want to build/extend a subway system on the outskirts of a small town in Wyoming. There are the usual subway-problems to solve, of course (hiring the right construction company, choosing the best route, buying the subway cars), but other than that it's pretty straightforward to implement the system because there aren't a huge number of constraints to satisfy. Scenario 2: Same as above, except now we need to build/extend the subway system in downtown Los Angeles. Here we face all of the problems we did in case (1), but also additional problems -- most of the applicable space is already in use, and has a vocal constituency which will protest loudly if we inconvenience them by repurposing, redesigning, or otherwise modifying the infrastructure that they rely on. Because of this, extensions to the system happen either very slowly and expensively, or they don't happen at all. I sometimes see a similar pattern with software development -- adding a new feature to a small/simple program is straightforward, but as the program grows, adding further new features becomes more and more difficult, if only because it is difficult to integrate the new feature without adversely affecting any of the large number of existing use-cases or user-constituencies. (even with a robust, adaptable program design, you run into the problem of the user interface becoming so elaborate that the program becomes difficult to learn or use) Is there a term for this phenomenon?

  Read the article

• How to prevent Network Manager from auto creating network connection profiles with "available to everyone" by default

  - by airtonix

  We have several laptops at work which use Ubuntu 11.10 64bit. I have our Wifi Access Point requiring WPA2-EAP Authentication (backed by a LDAP server). I have the staff using these laptops when doing presentations by using the Guest Account. So by default when you have a wifi card, network manager will display available Wireless Access Points. So the logical course of action for a Novice(tm) user is to single left click the easy to use option in the Network Manager drop down list... At this point the Staff Member (who is logged in with the guest account) expects to just be able to connect and enter any authentication details if required. But because they are using the Guest account, they won't ever have admin permissions (nor do I want them to), and so PolKit kicks in with a request for admin authorisation. I solved this part by modifying the PolKit permissions required to allow all users to create System Network Connections... However, because these Staff members are logging onto the Wifi Access Point with Ldap Credentials and because the Network Manager is now saving those credentials as a System Connection, their password is available for the next guest user session (because system connection profiles are stored in /etc/NetworkManager/system-connections.d/* ). It creates system connections by default because "Available to all users" is ticked by default when you quickly connect to a new wifi access point. I want Network Manager to not tick this by default. This way I can revert the changes I made to Polkit and users network connection profiles will be purged when they log out.

  Read the article

• UBUNTU's Network Connection Manger can't detect Huawei ETS2051 Modem device!

  - by Doctoa

  I have a modem device called Huawei ETS2051 and the Network Connection Manger can't detect it, but when I use Gnome-PPP it work fine but the problem is when I use Gnome-PPP; apps like Ubuntu software Center Can't reconice that's Iam connecting to the Internet so the app is just act like it's offline while other apps like web browsers and IM's work good under Gnome-PPP. any way what I want is to have a Full Ubuntu experince by making The Network Connection Manger detect my ETS2051. I have another 3G USB modem and The Network Connection Manger detect it and it's work just fine but the internet price for this one is high and I can't effort it so am count on that ETS2051 modem as you can see for it's low price and stable internet speed that satesfy my needs. More information: Gnome-PPP is a GUI for wvdial. the ETS2051 modem use a serial USB port. I have a Windows driver CD for the device. I have also find This qustion about the software Center acting like it's offline around wvdial and there's this launchpad bug. and am really insest to use Ubuntu Software Center so please no other software manger apps recomendation... I've also this Genius ColorPage HR6X Slim scanner that's Ubuntu can't detect it, so if you interset you can check and answer the qustion from here...

  Read the article

• Why connection in Python's DB-API does not have "begin" operation?

  - by newtover

  Working with cursors in mysql-python I used to call "BEGIN;", "COMMIT;", and "ROLLBACK;" explicitly as follows: try: cursor.execute("BEGIN;") # some statements cursor.execute("COMMIT;") except: cursor.execute("ROLLBACK;") then, I found out that the underlying connection object has the corresponding methods: try: cursor.connection.begin() # some statements cursor.connection.commit() except: cursor.connection.rollback() Inspecting the DB-API PEP I found out that it does not mention the begin() method for the connection object, even for the extensions. Mysql-python, by the way, throws the Deprecation Warning, when you use the method. sqlite3.connection, for example, does not have the methd at all. And the question is why there is no such method in the PEP? Is the statement somehow optional, is it enough to invoke commit() instead?

  Read the article

• Why implement DB connection pointer object as a reference counting pointer? (C++)

  - by DVK

  At our company one of the core C++ classes (Database connection pointer) is implemented as a reference counting pointer. To be clear, the objects are NOT DB connections themselves, but pointers to a DB connection object. The library is very old, and nobody who designed is around anymore. So far, nether I, nor any C++ experts in the company that I asked have come up with a good reason for why this particular design was chosen. Any ideas? It is introducing some problems (partially due to awful reference pointer implementation used), and I'm trying to understand if this design actually has some deep underlying reasons? The usage pattern these days seems to be that the DB connection pointer object is returned by a DB connection manager class, and it's somewhat unclear whether DB connection pointers were designed to be able to be used independently of DB connection manager.

  Read the article

• How to forward an Internet connection to another network?

  - by Naveen

  Can somebody please make a shot & sweet tutorial telling how to forward an Internet connection to different network interfaces in Ubuntu...? This is the idea: I'm using a 3G usb modem to get Internet on my laptop ,which is: ppp0 IP=10.225.174.70 My Wifi device is: wlan0 MAC=78:e4:00:d4:3d:85 These devices are determined from ifconfig command. I want to share ppp0's internet connection with wlan0 device, so I can connect any other device to wlan0 and browse internet from that device. Making a Hotspot using Network settings GUI doesn't do the trick because the other device won't receive Internet, it just connects to wlan0. I heard iptables can do this, but I'm totally confused by the alien commands seen online. I'm no expert in networking. Please compose a clear & simple answer using the above devices. This is a huge annoying problem for iPhone & tablet users came to Ubuntu from Windows.

  Read the article

• How do I run my XBOX XNA game without a network connection?

  - by Hugh

  I need to demo my XBOX XNA game in college. The college doesn't allow this type of device to connect to the network. I deployed my game to the Xbox and it is sitting in the games list along with my other games. It runs fine with a network connection but when its offline it comes up with an error message saying its needs a connection to run the game. This makes no sense, the game is deployed on the Xbox memory, it must be some security policy or something! Is there any way around this? The demo is on monday!

  Read the article

• Unable to use NSURLConnection to get contents of password/username protected webpage

  - by bubster

  I am trying to get the contents of a webpage that requires a password and user name to access. I am using a NSURLConnection object to get it however when I write the NSMutableData object that is returned to a file all I get is the login page. Normally when you try to load the password protected page when you are not logged in it redirects to the login page however I thought that if I provided valid credentials then this I would be able to view the password protected page. Also I do not know if it is relevant the website is using a microsoft mysql database on an IIS (internet information server). Note: [protectionSpace authenticationMethod] returns NSURLAuthenticationMethodServerTrust I am pretty unfamiliar with this so any ideas would be greatly appreciated. Below is all of the relevant code: - (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response { // This method is called when the server has determined that it // has enough information to create the NSURLResponse. // It can be called multiple times, for example in the case of a // redirect, so each time we reset the data. // receivedData is an instance variable declared elsewhere. [receivedData setLength:0]; } - (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data { // Append the new data to receivedData. // receivedData is an instance variable declared elsewhere. [receivedData appendData:data]; } - (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error { // release the connection, and the data object //[connection release]; // receivedData is declared as a method instance elsewhere //[receivedData release]; // inform the user NSLog(@"Connection failed! Error - %@ %@", [error localizedDescription], [[error userInfo] objectForKey:NSURLErrorFailingURLStringErrorKey]); } - (void)connectionDidFinishLoading:(NSURLConnection *)connection { // do something with the data // receivedData is declared as a method instance elsewhere NSLog(@"Succeeded! Received %d bytes of data",[receivedData length]); // release the connection, and the data object //[connection release]; //[receivedData release]; //Write data to a file [receivedData writeToFile:@"/Users/matsallen/Desktop/receivedData.html" atomically:YES]; } - (BOOL)connection:(NSURLConnection *)connection canAuthenticateAgainstProtectionSpace: (NSURLProtectionSpace *)protectionSpace { NSLog(@"The connection encountered a protection space. The authentication method is %@", [protectionSpace authenticationMethod]); secureTrustReference = [protectionSpace serverTrust]; //SecTrustResultType *result; //OSStatus status = SecTrustEvaluate(secureTrustReference, result); //NSLog(@"Result of the trust evaluation is %@",status); return YES; } - (void)connection:(NSURLConnection *)connection didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge { NSURLCredential *newCredential; newCredential = [NSURLCredential credentialWithUser:@"username" password:@"password" persistence:NSURLCredentialPersistenceForSession]; newCredential = [NSURLCredential credentialForTrust:secureTrustReference]; // [[challenge sender] useCredential:newCredential forAuthenticationChallenge:challenge]; // [[challenge sender] continueWithoutCredentialForAuthenticationChallenge:challenge]; } #pragma mark - View lifecycle - (void)viewDidLoad { receivedData = [[NSMutableData alloc] init]; [super viewDidLoad]; // Do any additional setup after loading the view, typically from a nib. // Create the request. NSURLRequest *theRequest=[NSURLRequest requestWithURL:[NSURL URLWithString:@"https://www.markallenonline.com/secure/maoCoaching.aspx"] cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0]; // create the connection with the request // and start loading the data NSURLConnection *theConnection=[[NSURLConnection alloc] initWithRequest:theRequest delegate:self]; if (theConnection) { // Create the NSMutableData to hold the received data. // receivedData is an instance variable declared elsewhere. receivedData = [NSMutableData data]; NSLog(@"Connection succeeded!"); } else { // Inform the user that the connection failed. NSLog(@"Connection failed!"); } }

  Read the article

• Android: HttpURLConnection not working properly

  - by giorgiline

  I'm trying to get the cookies from a website after sending user credentials through a POST Request an it seems that it doesn't work in android this way. ¿Am I doing something bad?. Please help. I've searched here in different posts but there's no useful answer. It's curious that this run in a desktop Java implementation it works perfect but it crashes in Android platform. And it is exactly the same code, specifically when calling HttpURLConnection.getHeaderFields(), it also happens with other member methods. It's a simple code and I don't know why the hell isn't working. DESKTOP CODE: This goes just in the main() HttpURLConnection connection = null; OutputStream out = null; try { URL url = new URL("http://www.XXXXXXXX.php"); String charset = "UTF-8"; String postback = "1"; String user = "XXXXXXXXX"; String password = "XXXXXXXX"; String rememberme = "on"; String query = String.format("postback=%s&user=%s&password=%s&rememberme=%s" , URLEncoder.encode(postback, charset) , URLEncoder.encode(user,charset) , URLEncoder.encode(password, charset) , URLEncoder.encode(rememberme, charset)); connection = (HttpURLConnection)url.openConnection(); connection.setRequestMethod("POST"); connection.setRequestProperty("Accept-Charset", charset); connection.setDoOutput(true); connection.setFixedLengthStreamingMode(query.length()); out = connection.getOutputStream (); out.write(query.getBytes(charset)); if (connection.getHeaderFields() == null){ System.out.println("Header null"); }else{ for (String cookie: connection.getHeaderFields().get("Set-Cookie")){ System.out.println(cookie.split(";", 2)[0]); } } } catch (IOException e){ e.printStackTrace(); } finally { try { out.close();} catch (IOException e) { e.printStackTrace();} connection.disconnect(); } So the output is: login_key=20ad8177db4eca3f057c14a64bafc2c9 FASID=cabf20cc471fcacacdc7dc7e83768880 track=30c8183e4ebbe8b3a57b583166326c77 client-data=%7B%22ism%22%3Afalse%2C%22showm%22%3Afalse%2C%22ts%22%3A1349189669%7D ANDROID CODE: This goes inside doInBackground AsyncTask body HttpURLConnection connection = null; OutputStream out = null; try { URL url = new URL("http://www.XXXXXXXXXXXXXX.php"); String charset = "UTF-8"; String postback = "1"; String user = "XXXXXXXXX"; String password = "XXXXXXXX"; String rememberme = "on"; String query = String.format("postback=%s&user=%s&password=%s&rememberme=%s" , URLEncoder.encode(postback, charset) , URLEncoder.encode(user,charset) , URLEncoder.encode(password, charset) , URLEncoder.encode(rememberme, charset)); connection = (HttpURLConnection)url.openConnection(); connection.setRequestMethod("POST"); connection.setRequestProperty("Accept-Charset", charset); connection.setDoOutput(true); connection.setFixedLengthStreamingMode(query.length()); out = connection.getOutputStream (); out.write(query.getBytes(charset)); if (connection.getHeaderFields() == null){ Log.v(TAG, "Header null"); }else{ for (String cookie: connection.getHeaderFields().get("Set-Cookie")){ Log.v(TAG, cookie.split(";", 2)[0]); } } } catch (IOException e){ e.printStackTrace(); } finally { try { out.close();} catch (IOException e) { e.printStackTrace();} connection.disconnect(); } And here there is no output, it seems that connection.getHeaderFields() doesn't return result. It takes al least 30 seconds to show the Log: 10-02 16:56:25.918: V/class com.giorgi.myproject.activities.HomeActivity(2596): Header null

  Read the article

• How to prevent WLAN connection from dropping permanently on a Fritz USB WLAN N stick?

  - by Chris

  I have a desktop with a Fritz USB WLAN N stick and tried Ubuntu 12.04. Installation went fine and WLAN is working. However, connection drops permanent. Reconnecting manually fixes it but after a few minutes it drops again. It's connected to a Vodafone 802 box with WLAN N fix set. It seems that it works when I switch off N mode. But I need to test. Can someone confirm this issue or is there another solution? I have another machine with 12.04 (HP 625 laptop) running where connection is stable.

  Read the article

• Are there non-programming related activities akin to solving programming problems ?

  - by julien

  I'm talking about particular activities, for which you can draw parallels with the specific kind of reasonning needed when solving programming problems. Counter examples are activities that would help in almost any situation, like : take a shower or any other, somewhat passive activities, which are only helpful in triggering this sort of asynchronous problem solving our brain does exercise, because you brain simply works better when you're fit EDIT : It seems this question was quite misunderstood. I wasn't asking about what you can do when stuck on a problem but rather, what kind of activities you have in you spare time that you think help you, more or less directly, solving programing problems.

  Read the article

• What do you do when practical problems get in the way of practical goals?

  - by P.Brian.Mackey

  UPDATE Source control is good to use. Sometimes, real world issues make it impractical to use. For example: If the team is not used to using source control, training problems can arise If a team member directly modifies code on the server, various issues can arise. Merge problems, lack of history, etc Let's say there's a project that is way out of sync. The physical files on the server differ in unknown ways over ~100 files. Merging would take not only a great knowledge of the project, but is also well beyond the ability to complete in the given time. Other projects are falling out of sync. Developers continue to have a distrust of source control and therefore compound the issue by not using source control. Developers argue that using source control is wasteful because merging is error prone and difficult. This is a difficult point to argue, because when source control is being so badly mis-used and source control continually bypassed, it is error prone indeed. Therefore, the evidence "speaks for itself" in their view. Developers argue that directly modifying source control saves time. This is also difficult to argue. Because the merge required to synchronize the code to start with is time consuming, across ~10 projects. Permanent files are often stored in the same directory as the web project. So publishing (full publish) erases these files that are not in source control. This also drives distrust for source control. Because "publishing breaks the project". Fixing this (moving stored files out of the solution subfolders) takes a great deal of time and debugging as these locations are not set in web.config and often exist across multiple code points. So, the culture persists itself. Bad practice begets more bad practice. Bad solutions drive new hacks to "fix" much deeper, much more time consuming problems. Servers, hard drive space are extremly difficult to come by. Yet, user expectations are rising. What can be done in this situation?

  Read the article

• Is there any way to simulate a slow connection between my server and an iPad (without installing anything on the server)?

  - by Clay Nichols

  Some of our webapp users have difficulty on slower connections. I"m trying to get a better idea of what that "speed barrier is" so I'd like to be able to test a variety of connection speeds. I've found ways to do this on Windows but no on the iPad, so I'm looking more for some sort of proxy service that'll work with any device (not running ON that device) I did find an article about using the CharlesProxy and providing a connection to another device, but I was hoping for something simpler (need not be free) Constraints * We are on a shared server so we can't install anything and we are limited in our control over that server. * I'd like to test an iPad, Android Tablet, Windows PC.

  Read the article

• can I put my sqlite connection and cursor in a function?

  - by steini

  I was thinking I'd try to make my sqlite db connection a function instead of copy/pasting the ~6 lines needed to connect and execute a query all over the place. I'd like to make it versatile so I can use the same function for create/select/insert/etc... Below is what I have tried. The 'INSERT' and 'CREATE TABLE' queries are working, but if I do a 'SELECT' query, how can I work with the values it fetches outside of the function? Usually I'd like to print the values it fetches and also do other things with them. When I do it like below I get an error Traceback (most recent call last): File "C:\Users\steini\Desktop\py\database\test3.py", line 15, in <module> for row in connection('testdb45.db', "select * from users"): ProgrammingError: Cannot operate on a closed database. So I guess the connection needs to be open so I can get the values from the cursor, but I need to close it so the file isn't always locked. Here's my testing code: import sqlite3 def connection (db, arg): conn = sqlite3.connect(db) conn.execute('pragma foreign_keys = on') cur = conn.cursor() cur.execute(arg) conn.commit() conn.close() return cur connection('testdb.db', "create table users ('user', 'email')") connection('testdb.db', "insert into users ('user', 'email') values ('joey', 'foo@bar')") for row in connection('testdb45.db', "select * from users"): print row How can I make this work?

  Read the article

• How to deal with OOP design problems in interviews?

  - by haps10

  This is a question where I seek guidance from fellow/senior developers to get into my dream company - it's a pioneer in OOP and Agile. I've already failed once to clear an interview. One part I feel most challenging is to come up with a proper Object Oriented design(classes, interfaces, methods, interactions etc.) in a very short time for certain situations like Pacman, Game Of Life and so on. As the problems are unprecedented ones - my approach is mostly to try different things and then make decisions - which they feel is not clear and not what they expect from a developer with 5+ years of experience. I've already studied a few books on patterns, OOP - it didn't help me much and I think it'll take a bit more than that. Could some one please guide on what specifically shall I practice so that I can do better at design problems as above. I want to refine my approach and have a better thought process.

  Read the article

• Why does my internet connection get cut off and is slow sometimes?

  - by user3716773

  When I first set up my internet connection it was all good and fast but after 2 months the connection started to be slow sometimes and sometimes there is no connection until i turn off my wifi then turn it on again on the laptop. And sometimes I have to restart the router. I don't know what's wrong. I think there is something wrong with the router because this problem happens with my brother's laptop and my phone too.

  Read the article

• MySQL-5.5.10 - Lost connection to MySQL server during query (Both Web Clients and MySQL Slaves)

  - by kwiksand

  We've just upgraded our existing MySQL5.1 DB servers to newer (much better) hardware with MySQL 5.5, and things have been going mostly smoothly for almost 6 weeks. Just the last few days, I've noticed a few errors, such as: From a MySQL Slave: [ERROR] Error reading packet from server: Lost connection to MySQL server during query ( server_errno=2013) Or From Apache/Other: Lost connection to MySQL server at 'reading initial communication packet', system error: 110 At one point this evening, many webnodes reported this error for a three minute period (many such reports as this was in a busy period). However, the issues don't appear to correspond with any times of extreme load. For all intents and purposes, the connection/thread load on MySQL is at a normal rate (between about 10 and 40 connected threads), and Web load has been a LOT higher at times over the last few weeks. Could there bee other reasons for these connection errors, that I'm not seeing?

  Read the article

• WTH? Upgrading Ubuntu 9.10 to 10.04 Problem: No Internet Connection?

  - by damx

  Earlier today I tried upgrading my Ubuntu 9.10 Karmic Kaola from the update manager. (FYI: all 9.10 updates were applied prior to this) Everything was going well downloading until I got an error dialog informing me that some software packages weren't downloaded because of an Internet connection. Would say it was halfway thru. Anyway, Was told that the software packages that it did download, however, would kept and I figure it's not a big deal. Just run it again. But first ran Firefox to verify my connection as I haven't had any connection problems. But my internet connection was/is fine as evident by this posting. With that cleared, I ran the update manager again, clicked on "Upgrade" and this time I received "Could not download the release notes. Please check your internet connection" huh? This is my first time dealing w/ Ubuntu and my first upgrade so I am hoping someone can help. Not sure what the problem can be. I am can surf the web w/ no problems. Please help. PS: There was no installing at any point. Just downloading. PSS: The software it managed to download the first time around is now visible in the update manager but don't think I should install as I see in the compiz description it's for v1:0.8-4-0ubuntu2 I figure it's designed for 10.04 and might ruin things further if I install

  Read the article

• Mac OS X 10.8 VPN Server: Bypass VPN for LAN traffic (routing LAN traffic to secondary connection)

  - by Dan Robson

  I have somewhat of an odd setup for a VPN server with OS X Mountain Lion. It's essentially being used as a bridge to bypass my company's firewall to our extranet connection - certain things our team needs to do require unfettered access to the outside, and changing IT policies to allow traffic through the main firewall is just not an option. The extranet connection is provided through a Wireless-N router (let's call it Wi-Fi X). My Mac Mini server is configured with the connection to this router as the primary connection, thus unfettered access to the internet via the router. Connections to this device on the immediate subnet are possible through the LAN port, but outside the subnet things are less reliable. I was able to configure the VPN server to provide IP addresses to clients in the 192.168.11.150-192.168.11.200 range using both PPTP and L2TP, and I'm able to connect to the extranet through the VPN using the standard Mac OS X VPN client in System Preferences, however unsurprisingly, a local address (let's call it internal.company.com) returns nothing. I tried to bypass the limitation of the VPN Server by setting up Routes in the VPN settings. Our company uses 13.x.x.x for all internal traffic, instead of 10.x.x.x, so the routing table looked something like this: IP Address ---------- Subnet Mask ---------- Configuration 0.0.0.0 248.0.0.0 Private 8.0.0.0 252.0.0.0 Private 12.0.0.0 255.0.0.0 Private 13.0.0.0 255.0.0.0 Public 14.0.0.0 254.0.0.0 Private 16.0.0.0 240.0.0.0 Private 32.0.0.0 224.0.0.0 Private 64.0.0.0 192.0.0.0 Private 128.0.0.0 128.0.0.0 Private I was under the impression that if nothing was entered here, all traffic was routed through the VPN. With something entered, only traffic specifically marked to go through the VPN would go through the VPN, and all other traffic would be up to the client to access using its own default connection. This is why I had to specifically mark every subnet except 13.x.x.x as Private. My suspicion is that since I can't reach the VPN server from outside the local subnet, it's not making a connection to the main DNS server and thus can't be reached on the larger network. I'm thinking that entering hostnames like internal.company.com aren't kicked back to the client to resolve, because the server has no idea that the IP address falls in the public range, since I suspect (probably should ping test it but don't have access to it right now) that it can't reach the DNS server to find out anything about that hostname. It seems to me that all my options for resolving this all boil down to the same type of solution: Figure out how to reach the DNS with the secondary connection on the server. I'm thinking that if I'm able to do [something] to get my server to recognize that it should also check my local gateway (let's say Server IP == 13.100.100.50 and Gateway IP == 13.100.100.1). From there Gateway IP can tell me to go find DNS Server at 13.1.1.1 and give me information about my internal network. I'm very confused about this path -- really not sure if I'm even making sense. I thought about trying to do this client side, but that doesn't make sense either, since that would add time to each and every client side setup. Plus, it just seems more logical to solve it on the server - I could either get rid of my routing table altogether or keep it - I think the only difference would be that internal traffic would also go through the server - probably an unnecessary burden on it. Any help out there? Or am I in over my head? Forward proxy or transparent proxy is also an option for me, although I have no idea how to set either of those up. (I know, Google is my friend.)

  Read the article

• Upgrading Ubuntu 9.10 to 10.04 Problem: No Internet Connection?

  - by damx

  Earlier today I tried upgrading my Ubuntu 9.10 Karmic Kaola from the update manager. (FYI: all 9.10 updates were applied prior to this) Everything was going well downloading until I got an error dialog informing me that some software packages weren't downloaded because of an Internet connection. Would say it was halfway thru. Anyway, Was told that the software packages that it did download, however, would kept and I figure it's not a big deal. Just run it again. But first ran Firefox to verify my connection as I haven't had any connection problems. But my internet connection was/is fine as evident by this posting. With that cleared, I ran the update manager again, clicked on "Upgrade" and this time I received "Could not download the release notes. Please check your internet connection" This is my first time dealing with Ubuntu and my first upgrade so I am hoping someone can help. Not sure what the problem can be. I can surf the web with no problems. PS: There was no installing at any point. Just downloading. PSS: The software it managed to download the first time around is now visible in the update manager but don't think I should install as I see in the compiz description it's for v1:0.8-4-0ubuntu2 I figure it's designed for 10.04 and might ruin things further if I install.

  Read the article

• Why is my Wifi connection slower than ethernet even though bandwidth should saturated?

  - by supercheetah

  I'm wondering why it is that my wireless connection is slower than my wired connection for things going to the outside world (so, not files being transferred within the network), which is should be faster than the outside connection, which, I would think, would mean that downloading something like an ISO or other large file from the Internet should be the same either way since that should saturate the connection anyway. Does it have something to do with the encryption (WPA)? Could it have something to do with MTU since the MTU for ethernet can be in the range of 1500 to 9000 bytes, and 2304 bytes for 802.11? Do wireless packets have to be buffered, whereas this wouldn't be an issue with ethernet? What's the math behind the difference?

  Read the article

• How do I choose the number of connection for load balancer?

  - by user105196

  I want to add hardware load balancer for apache and I want to know how many people are connected to my server to to choose the type of load balancer: Local Load Balancing with SSL - 250 Connections Local Load Balancing with SSL - 500 Connections Local Load Balancing with SSL - 1000 Connections I run the following commands in the same time: netstat -nt|grep -c :443 ( all connection wait and ESTABLISHED) result : 1208 netstat -ant | grep 443 | grep EST | wc -l ( just ESTABLISHED connection) result :106 My question: Whichever is the correct value to choose the load balancer all connection or just ESTABLISHED ?

  Read the article

• Can make the proxy settings invisible when I share my internet connection via wifi?

  - by Neil

  This is probably a long shot... I have an HTC Desire and frustratingly found out after I got it that it doesn't support network proxy settings. We have a wireless network at my office that uses a proxy. My desktop at work runs ubuntu. I was wondering if the following set up would work: Plug a USB Wireless adapter into the desktop that has a working internet connection using the proxy. Setup the wireless adapter as an ad-hoc network Share the internet connection over the ad-hoc network. Make it so that the use of the proxy is invisible to users of the shared network connection. Connect the Android phone to the ad-hoc wireless network and utilise the internet connection. My question is this: Is this possible or should I give up now and not even try? I think I can handle steps 1, 2, 3 and 5. I just have no idea if step 4 even makes sense, let alone is possible. Thanks

  Read the article

• How do I prevent TCP connection freezes over an OpenVPN network?

  - by Jason R

  New details added at the end of this question; it's possible that I'm zeroing in on the cause. I have a UDP OpenVPN-based VPN set up in tap mode (I need tap because I need the VPN to pass multicast packets, which doesn't seem to be possible with tun networks) with a handful of clients across the Internet. I've been experiencing frequent TCP connection freezes over the VPN. That is, I will establish a TCP connection (e.g. an SSH connection, but other protocols have similar issues), and at some point during the session, it seems that traffic will cease being transmitted over that TCP session. This seems to be related to points at which large data transfers occur, such as if I execute an ls command in an SSH session, or if I cat a long log file. Some Google searches turn up a number of answers like this previous one on Server Fault, indicating that the likely culprit is an MTU issue: that during periods of high traffic, the VPN is trying to send packets that get dropped somewhere in the pipes between the VPN endpoints. The above-linked answer suggests using the following OpenVPN configuration settings to mitigate the problem: fragment 1400 mssfix This should limit the MTU used on the VPN to 1400 bytes and fix the TCP maximum segment size to prevent the generation of any packets larger than that. This seems to mitigate the problem a bit, but I still frequently see the freezes. I've tried a number of sizes as arguments to the fragment directive: 1200, 1000, 576, all with similar results. I can't think of any strange network topology between the two ends that could trigger such a problem: the VPN server is running on a pfSense machine connected directly to the Internet, and my client is also connected directly to the Internet at another location. One other strange piece of the puzzle: if I run the tracepath utility, then that seems to band-aid the problem. A sample run looks like: [~]$ tracepath -n 192.168.100.91 1: 192.168.100.90 0.039ms pmtu 1500 1: 192.168.100.91 40.823ms reached 1: 192.168.100.91 19.846ms reached Resume: pmtu 1500 hops 1 back 64 The above run is between two clients on the VPN: I initiated the trace from 192.168.100.90 to the destination of 192.168.100.91. Both clients were configured with fragment 1200; mssfix; in an attempt to limit the MTU used on the link. The above results would seem to suggest that tracepath was able to detect a path MTU of 1500 bytes between the two clients. I would assume that it would be somewhat smaller due to the fragmentation settings specified in the OpenVPN configuration. I found that result somewhat strange. Even stranger, however: if I have a TCP connection in the stalled state (e.g. an SSH session with a directory listing that froze in the middle), then executing the tracepath command shown above causes the connection to start up again! I can't figure out any reasonable explanation for why this would be the case, but I feel like this might be pointing toward a solution to ultimately eradicate the problem. Does anyone have any recommendations for other things to try? Edit: I've come back and looked at this a bit further, and have found only more confounding information: I set the OpenVPN connection to fragment at 1400 bytes, as shown above. Then, I connected to the VPN from across the Internet and used Wireshark to look at the UDP packets that were sent to the VPN server while the stall occurred. None were greater than the specified 1400 byte count, so the fragmentation seems to be functioning properly. To verify that even a 1400-byte MTU would be sufficient, I pinged the VPN server using the following (Linux) command: ping <host> -s 1450 -M do This (I believe) sends a 1450-byte packet with fragmentation disabled (I at least verified that it didn't work if I set it to an obviously-too-large value like 1600 bytes). These seem to work just fine; I get replies back from the host with no issue. So, maybe this isn't an MTU issue at all. I'm just confused as to what else it might be! Edit 2: The rabbit hole just keeps getting deeper: I've now isolated the problem a bit more. It seems to be related to the exact OS that the VPN client uses. I have successfully duplicated the problem on at least three Ubuntu machines (versions 12.04 through 13.04). I can reliably duplicate an SSH connection freeze within a minute or so by just cat-ing a large log file. However, if I do the same test using a CentOS 6 machine as a client, then I don't see the problem! I've tested using the exact same OpenVPN client version as I was using on the Ubuntu machines. I can cat log files for hours without seeing the connection freeze. This seems to provide some insight as to the ultimate cause, but I'm just not sure what that insight is. I have examined the traffic over the VPN using Wireshark. I'm not a TCP expert, so I'm not sure what to make of the gory details, but the gist is that at some point, a UDP packet gets dropped due to the limited bandwidth of the Internet link, causing TCP retransmissions inside the VPN tunnel. On the CentOS client, these retransmissions occur properly and things move on happily. At some point with the Ubuntu clients, though, the remote end starts retransmitting the same TCP segment over and over (with the transmit delay increasing between each retransmission). The client sends what looks like a valid TCP ACK to each retransmission, but the remote end still continues to transmit the same TCP segment periodically. This extends ad infinitum and the connection stalls. My question here would be: Does anyone have any recommendations for how to troubleshoot and/or determine the root cause of the TCP issue? It's as if the remote end isn't accepting the ACK messages sent by the VPN client. One common difference between the CentOS node and the various Ubuntu releases is that Ubuntu has a much more recent Linux kernel version (from 3.2 in Ubuntu 12.04 to 3.8 in 13.04). A pointer to some new kernel bug maybe? I'm assuming that if that were so, then I wouldn't be the only one experiencing the problem; I don't think this seems like a particularly exotic setup.

  Read the article

• How can I change the connection timeout setting in Firefox?

  - by gylns

  When I load a page which can't be connected for some reasons, before Firefox shows the error "The connection has timed out", I will wait for about three minutes. I want change the Firefox connection timeout value to 20 seconds. I found something here http://stackoverflow.com/questions/1342310/where-can-i-find-the-default-timeout-settings-for-all-browsers, but it doesn't mention how to set the connection timeout value, please help!

  Read the article

< Previous Page | 181 182 183 184 185 186 187 188 189 190 191 192  | Next Page >