Search Results

Search found 370 results on 15 pages for 'intermittent'.

Page 6/15 | < Previous Page | 2 3 4 5 6 7 8 9 10 11 12 13  | Next Page >

  • Is my dns server being attacked? And what should I do about it?

    - by Mnebuerquo
    I've been having some intermittent dns problems with a web server, where certain isp's dns servers don't have my hostnames in cache and fail to look them up. At the same time, queries to opendns for those hostnames resolve correctly. It's intermittent, and it always works fine for me, so it's hard to identify the problem when someone reports connectivity problems to my site. In trying to figure this out, I've been looking at my logs to see if there are any errors I should know about. I found thousands of the following messages in my logs, from different ip's, but all requesting similar dns records: May 12 11:42:13 localhost named[26399]: client 94.76.107.2#36141: query (cache) 'burningpianos.com/MX/IN' denied May 12 11:42:13 localhost named[26399]: client 94.76.107.2#29075: query (cache) 'burningpianos.com/MX/IN' denied May 12 11:42:13 localhost named[26399]: client 94.76.107.2#47924: query (cache) 'burningpianos.com/MX/IN' denied May 12 11:42:13 localhost named[26399]: client 94.76.107.2#4727: query (cache) 'burningpianos.com/MX/IN' denied May 12 11:42:14 localhost named[26399]: client 94.76.107.2#16153: query (cache) 'burningpianos.com/MX/IN' denied May 12 11:42:14 localhost named[26399]: client 94.76.107.2#40267: query (cache) 'burningpianos.com/MX/IN' denied May 12 11:43:35 localhost named[26399]: client 82.209.240.241#63507: query (cache) 'burningpianos.com/MX/IN' denied May 12 11:43:35 localhost named[26399]: client 82.209.240.241#63721: query (cache) 'burningpianos.org/MX/IN' denied May 12 11:43:36 localhost named[26399]: client 82.209.240.241#3537: query (cache) 'burningpianos.com/MX/IN' denied I've read of Dan Kaminski's dns cache poisoning vulnerability, and I'm wondering if these log records are an attempt by some evildoer to attack my dns server. There are thousands of records in my logs, all requesting "burningpianos", some for com and some for org, most looking for an mx record. There are requests from multiple ip's, but each ip will request hundreds of times per day. So this smells to me like an attack. What is the defense against this?

    Read the article

  • DNS requests failing from computers that can ping DNS server

    - by dunxd
    I have a situation where computers in some of our remote offices from time to time lose the ability to use our DNS server (in head office) to resolve hostnames. The offices are connected via VPN using Cisco ASA 5505 (VPNclient config rather than Site to Site). Ping to the IP address of the DNS server works. But nslookup will get a "no response from server" message. Computers in other locations can use DNS fine. This is an intermittent problem. One day/hour it works, another it doesn't. Other offices connected in the same way work when another doesn't. No config changes have been made on routers around the time we see the problem. Some users have reported that the problem goes away after doing a repair connection in Windows XP. I think this could be caused by the DNS cache being flushed as part of this - the Windows DNS cache makes the intermittent problem look less so because it caches failed lookups as well as successful ones. However, it is possible some other aspect of Windows is involved. Windows 7 clients have also had the same problem. Any pointers on deeper troubleshooting, or anyone else found this?

    Read the article

  • Specific DNS sometimes resolves to wildcard, incorrectly

    - by Mojo
    I have an intermittent problem, and I'm not sure where to start trying to troubleshoot it. In our dev environment, we have two visible IP addresses on load balancers, one to the front-end, and one to a number of back-end service machines. The front-end is configured to take a wildcard DNS name to support generic "portals." dev.example.com A 10.1.1.1 *.dev.example.com CNAME dev.example.com The back-end servers are all specific names within the same space: core.dev.example.com A 10.1.1.2 cms.dev.example.com CNAME core.dev.example.com search.dev.example.com CNAME core.dev.example.com Here's the problem. Periodically a developer or a program trying to reach, say, cms.dev.example.com will get a result that points to the front-end, instead of the back-end load balancer: cms.dev.example.com is an alias to core.dev.example.com core.dev.example.com is an alias to dev.example.com (WRONG!) dev.example.com 10.1.1.1 The developers are all on Mac OS X machines, though I've seen the problem occur on an Ubuntu machine as well, using a local cloud host DNS resolver. Sometimes the developer is using a VPN, which directs the DNS to its own resolver, and sometimes he's on the local net using a DNS resolver assigned by the NAT router. Sometimes clearing the Mac OS X DNS cache, logging into the VPN, then logging out of the VPN, will make the problem go away. The origin authoritative server is on zerigo, and a dig directly to their name servers always seems to give the correct answer. The published DNS cache time for these records is 15 minutes, but the problem has been intermittent for about a week. Any troubleshooting suggestions?

    Read the article

  • Unexpected media key behavior on new Acer Aspire

    - by Morgan May
    I'm having weird issues with the media keys (play/pause, previous, next, etc.) on a new Acer Aspire laptop. This is the first Acer I've owned and also my first Windows 7 computer, so I'm not sure whether the behavior is a result of some hidden Acer process that I haven't rooted out yet, or some Windows 7 option that I'm not aware of, or something else. I'm experiencing two issues that I suspect are related. Both problems are intermittent but happen more often than not. The media player I'm using is Winamp. I'm pretty sure I've had the same problem when using other media players, but when I tried to verify that before posting this, I only had the problems with Winamp. Because the problems are intermittent, I'm not sure if that's significant. 1) When I press the Play/Pause media key, in addition to playing or pausing the media player, it brings up a little menu in the center of the screen that lists my removable drives (CD/DVD, USB drives, etc.). To make the menu go away I have to either click away from it or hit Escape. Selecting a drive on the menu doesn't seem to do anything. 2) When I press the Previous or Next media keys, it skips 2+ tracks instead of just one (the exact number seems to vary). I've poked around all the control panel options that I can find, and looked through all the utilities that came with the computer with no luck. There's nothing that I can find in the (very slim) documentation, either. I have a hunch that the problem is caused by whatever utility manages global hotkeys, but I haven't found any way to configure that. Any guidance would be greatly appreciated. UPDATE: It looks like Winamp was the culprit. I did have the problem when using other media players, but when I uninstalled Winamp, the problem went away. I'd like to use Winamp, but I can survive with other players.

    Read the article

  • Character encoding issues when generating MD5 hash cross-platform

    - by rogueprocess
    This is a general question about character encoding when using MD5 libraries in various languages. My concern is: suppose I generate an MD5 hash using a native Python string object, like this: message = "hello world" m = md5() m.update(message) Then I take a hex version of that MD5 hash using: m.hexdigest() and send the message & MD5 hash via a network, let's say, a JMS message or a HTTP request. Now I get this message in a Java program in the form of a native Java string, along with the checksum. Then I generate an MD5 hash using Java, like this (using the Commons Codec library): String md5 = org.apache.commons.codec.digest.DigestUtils.DigestUtils.md5Hex(s) My feeling is that this is wrong because I have not specified character encodng at either end. So the original hash will be based on the bytes of the Python version of the string; the Java one will be based on the bytes of the Java version of the string , these two byte sequences will often not be the same - is that right? So really I need to specify "UTF-8" or whatever at both ends right? (I am actually getting an intermittent error in my code where the MD5 checksum fails, and I suspect this is the reason - but because it's intermittent, it's difficult to say if changing this fixes it or not. ) Thank you!

    Read the article

  • IKImageView, Buttons work intermittently in 10.5 but ok in 10.6

    - by markhunte
    Hi all, In IB,I have connected some buttons to a IKImageView. Using its received Action 'ZoomIn:', 'ZoomOut:','ZoomImageToActualSize:' When I build for 10.6 I have no issues these work as expected. But in 10.5 (ppc), they sometimes work as expected and sometimes do not. I have even tried it programatically. But I get the same results. It is intermittent with each build after I have made some small change in IB that I need. But not changes that should affect how the view acts. The only buttons that seem to work through out are 'ZoomImageToFit' and the rotate ones. When the do not work as expected, I see no change to the current image in the view, but when my app (/s, I have had this issue before in different apps) changes the image The view reflects the last request from a button. So for example when it does not work. An image is displayed, I click the 'ZoomImageToActualSize:' button, nothing happens. I load a new image and it is displayed at Actual size. Example when it does work. An image is displayed, I click the 'ZoomImageToActualSize:' button, It is displayed at Actual size. By the way, I know I can reset the view default , before I load a new image. Also if I run the 10.5 app in 10.6, it works ok, but as above I get intermittent results with the same build on multible 10.5 machines. Does anyone know what is going on, is this a known bug? Thanks for any help. MH

    Read the article

  • OS X Snow Leopard 10.6 Refuses to Load Websites the first time intermittently

    - by Brandon
    Many times when I am browsing the web, Snow Leopard will sit and load a site for 20 seconds or more, until it times out and says it cannot be displayed. If I refresh, it loads RIGHT away, every time. The issue is intermittent but happens from once every couple of days to a few times a day. So the long and short of it is this: Aluminum MacBook (Non-Pro) 2.4GHz Core2Duo, 4GB DDR3 I am using 10.6.6 but I have had this issue since 10.6.0 It happens in Firefox, Chrome, and Safari I have flushed my DNS (using the command 'blablabla flush') I am using custom DNS servers which I hoped would fix it but it had no effect* I am running Apache currently but haven't been for most of the time I've reformatted multiple times, always experiencing the issue I am on Cox cable internet, with a Motorola Surfboard & a Belkin F6D4230-4 v1 (Pre?) N wireless router. I've put the router in G only & N only & G+N to no effect It seems to be domain dependant as I can sometimes load the Google cache right away, and sometimes other sites will load but Google will refuse My Powerbook G4 with Leopard, other Windows XP laptops, & my wired Win7 desktop do not suffer from the issue. *I recently started using these to escape the awful Cox redirect page on timeouts I'm almost positive the issue has happened on other networks but I can't recall a specific instance (I have a terrible memory). The problem is intermittent and fixable enough (I just have to wait until it times out and hit refresh one time) but incredibly annoying since I'm constantly reading documentation from a large variety of sites. EDIT: To clarify, this happens with ALL sites, not only specific sites. I haven't been able to detect any pattern to the failures, but one day Google.com will refuse to load while reddit.com will, and the next day vice versa. Keep in mind that waiting for a timeout and hitting refresh loads the page right away, every time. If I don't wait for the timeout, opening more links, hitting refresh, and clicking the link a billion times have no effect. It seems to be domain neutral, affecting sites seemingly at random. It doesn't seem to have anything to do with connection inactivity either, because I will be SSHed into different servers, uploading files, browsing, downloading, etc, and it will just quit loading Jquery.com (for example) until I sit and wait for a timeout. /EDIT This is my last resort. Please, someone, tell me what is happening. Thank you.

    Read the article

  • How to place a dropbox file into other dropbox

    - by Nrew
    There is this file that I really want to download. The kahel os live cd I tried downloading it with 45kbps download rate and it would take 3 hours. And the connection is intermittent. So my download was cut. Is it possible to treat the file as your own and then put it to your own dropbox. And from there it would continue downloading.

    Read the article

  • Server suffering serious speed drop

    - by Tar
    As you can see from the picture http://i.imgur.com/UpDZh.png), my server is suffering a serious drop in speed. This is intermittent and has been happening for the past 3 or 4 hours. The server has 1gbps uplink so I can't figure out why it's happening. Checking bandwidth monitoring tools like bwm-ng and dstat show normal speeds of like 150kb/s outbound traffic. Just now I was completely disconnected from SSH.

    Read the article

  • Windows XP procedurally drop packets

    - by Michael J Mulligan
    We have a need in our office network to procedurally drop incoming packets on an XP machine acting as a server. By procedurally we mean to drop a percentage of packets incoming on the XP machine from a specific IP. Asked here because these seem like server related questions. And none of us have really any idea how to execute this. Another option is to introduce intermittent latency for an incoming IP. Thank you for your help.

    Read the article

  • Hamachi network problem in virtual machine

    - by Ngu Soon Hui
    Hello, I have two virtual instances of Windows XP, and they are members of my Hamachi network. The problem is that the virtual machines seem to have a connectivity problem. The connection is intermittent, at best. Is there any known issues of hamachi, with Virtual Machine running on Windows XP?

    Read the article

  • MacBook Pro Intermiten Wireless Connection

    - by Pisaro
    Hello SuperUsers I bought a macbook pro last year ( i liked it a lot but i am still getting use to it), and since then i have been experiencing intermittent wireless connection. I researched a lot in internet about what could be causing this but there are many reason that it could be affecting i posted my questions in Apple's help forum and i haven't received any help yet I am wondering if anybody had or still has the same problem than me Any info would be more than appreciated thanks Pisaro - London

    Read the article

  • Dell 36400 Display issue - "doubling up" intermittently

    - by alex
    I've got a Dell E6400 It's suddenly developed an intermittent fault with the display Every now and again, it seems to boot up with "double vision" By that I mean, its split horizontally, with each half showing the same thing, but with low resolution, and looks grainy - if that makes sense (I will try to get a couple of pictures if I can) I haven't changed any hardware or anything. I have re-built windows, to see if that fixed the problem, it didn't. I've upgraded the BIOS to see if that would help, still same problem. I'm out of ideas :-(

    Read the article

  • "Zinc Whisker" issues?

    - by Dizzle
    Good morning; We've been having intermittent power supplies failures in our data center that have been preliminarily attributed to "zinc whiskers". I'm just starting to read about them (I just Googled the term and started picking stuff), and I'm interested in others experiences with them and any cleanup and recovery experiences. Thanks!

    Read the article

  • Do RAID controllers commonly have SATA drive brand compatibility issues?

    - by Jeff Atwood
    We've struggled with the RAID controller in our database server, a Lenovo ThinkServer RD120. It is a rebranded Adaptec that Lenovo / IBM dubs the ServeRAID 8k. We have patched this ServeRAID 8k up to the very latest and greatest: RAID bios version RAID backplane bios version Windows Server 2008 driver This RAID controller has had multiple critical BIOS updates even in the short 4 month time we've owned it, and the change history is just.. well, scary. We've tried both write-back and write-through strategies on the logical RAID drives. We still get intermittent I/O errors under heavy disk activity. They are not common, but serious when they happen, as they cause SQL Server 2008 I/O timeouts and sometimes failure of SQL connection pools. We were at the end of our rope troubleshooting this problem. Short of hardcore stuff like replacing the entire server, or replacing the RAID hardware, we were getting desperate. When I first got the server, I had a problem where drive bay #6 wasn't recognized. Switching out hard drives to a different brand, strangely, fixed this -- and updating the RAID BIOS (for the first of many times) fixed it permanently, so I was able to use the original "incompatible" drive in bay 6. On a hunch, I began to assume that the Western Digital SATA hard drives I chose were somehow incompatible with the ServeRAID 8k controller. Buying 6 new hard drives was one of the cheaper options on the table, so I went for 6 Hitachi (aka IBM, aka Lenovo) hard drives under the theory that an IBM/Lenovo RAID controller is more likely to work with the drives it's typically sold with. Looks like that hunch paid off -- we've been through three of our heaviest load days (mon,tue,wed) without a single I/O error of any kind. Prior to this we regularly had at least one I/O "event" in this time frame. It sure looks like switching brands of hard drive has fixed our intermittent RAID I/O problems! While I understand that IBM/Lenovo probably tests their RAID controller exclusively with their own brand of hard drives, I'm disturbed that a RAID controller would have such subtle I/O problems with particular brands of hard drives. So my question is, is this sort of SATA drive incompatibility common with RAID controllers? Are there some brands of drives that work better than others, or are "validated" against particular RAID controller? I had sort of assumed that all commodity SATA hard drives were alike and would work reasonably well in any given RAID controller (of sufficient quality).

    Read the article

  • Complete stack traces from Hyperic

    - by Mike Kushner
    I've setup Hyperic to run on our CI-machine, and every once in a while it reacts to some random stack trace and sends of an alert. So far so good, we've caught a lot of intermittent bugs that way. My only issue is that the alert only contains the first error line and not the entire stack trace, which requires me to access the machine and look at the logs manually. Is there any way to modify the alert message to contain more information, alternatively to include the log file in the alert mail?

    Read the article

  • Restart browser on error

    - by billfredtom
    Is there a way to restart a browser (Internet Explorer, Firefox, etc) automatically upon receiving an error such as a DNS error or Page not found? Background: It is for a web based signage application that has intermittent network drop outs, therefore if there's no internet, and the sign tries to go to the next page, an error occurs on browser, and we get one big ugly sign. We need a way to either restart the browser, or customise displayed error messages to use javascript to try redirection to the live sign again.

    Read the article

  • Dell E6400 Display issue - "doubling up" intermittently

    - by alex
    I've got a Dell E6400 It's suddenly developed an intermittent fault with the display Every now and again, it seems to boot up with "double vision" By that I mean, its split horizontally, with each half showing the same thing, but with low resolution, and looks grainy - if that makes sense (I will try to get a couple of pictures if I can) I haven't changed any hardware or anything. I have re-built windows, to see if that fixed the problem, it didn't. I've upgraded the BIOS to see if that would help, still same problem. I'm out of ideas :-(

    Read the article

  • Do certain usb ports work better on my IBM T60?

    - by Xavierjazz
    Hi. I am using a Microsoft wireless phone ear piece and I have had the receiver plugged into the USB port on the Left Hand side. I have been getting intermittent success with the signal. I have recently tried plugging it in to one of the ports on the top Right Hand side, and it seems that I am getting a better signal. Is there a difference between the ports? Thanks.

    Read the article

  • Computer name not appearing on network

    - by stib
    I can connect to other computers on my home network (ubuntu + OSX machines) using the IP address, but I can't connect using the netbios name. On the mac the name appears in Finder but if I try to connect (goconnect to server smb://[email protected]) it doesn't work, while smb://[email protected] does. Same with ssh, ping and afp between the macs. This is a intermittent problem. It has worked in the past.

    Read the article

  • Dell Inspiron 1525 - internal hard drive not detected

    - by GingerT
    Others have asked about this issue but had intermittent access to their HD, therefore their results did not apply to this situation. I have tried reseating the HD to no effect. I also tried booting from the Internal HD to no effect. Next step get a connector cable and move the data to a different HD, or send in for HD recovery? Any suggestions?

    Read the article

  • What process is making that sound?

    - by harschware
    My Windows 7 system makes an intermittent ding sound (like a single chime, or bell). I don't know which process does it. So, my question is: Is there software out there that can tell me which processes are currently sending output to the sound device?

    Read the article

  • What brand of wireless router would be compatible with many broadband modems and easy to use?

    - by Junior Mayhé
    Good afternoon I'm having too many intermittent problems with my DLINK DIR 400 router: Wireless connection is lost with no reason. Perhaps the current router is incompatible with this Scientific Atlanta cable modem DPC 2100R2. Scientific Atlanta is a Cisco company, but I'm really worried about this combination DLink - Cisco. Could anyone recommend me a good wireless router for Windows Vista / Windows 7? Thank you

    Read the article

  • Reset network (airport) connections from the command line

    - by Klaus Byskov Hoffmann
    I have this MacBook Pro that has intermittent problems connecting to my Wifi network. Sometimes it helps to disable/re-enable airport and sometimes I have to restart the computer to get my network running again. Has anyone experienced this? And is there a command I can run that would do the same as I do when I restart the computer (short of actually restarting it, obviously) or at least a command that restarts the airport service? Thanks in advance.

    Read the article

  • What brand of wireless router would be compatible with many broadband modems and easy to use?

    - by Junior Mayhé
    Good afternoon I'm having too many intermittent problems with my DLINK DIR 400 router: Wireless connection is lost with no reason. Perhaps the current router is incompatible with this Scientific Atlanta cable modem DPC 2100R2. Scientific Atlanta is a Cisco company, but I'm really worried about this combination DLink - Cisco. Could anyone recommend me a good wireless router for Windows Vista / Windows 7? Thank you

    Read the article

< Previous Page | 2 3 4 5 6 7 8 9 10 11 12 13  | Next Page >