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Error 64 “ The specified network name is no longer available” while browsing Internet through ISA Server 2006 - Yuri Diogenes's Blog - Site Home - TechNet Blogs

Yuri Diogenes's Blog

Thoughts from a Senior Content Developer @ Microsoft Data Center, Devices & Enterprise Client – CSI (Enterprise Mobility Team)

Error 64 “ The specified network name is no longer available” while browsing Internet through ISA Server 2006

Error 64 “ The specified network name is no longer available” while browsing Internet through ISA Server 2006

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1. Another error 64?

 

After posting one of the reasons why ISA Server 2006 can come up with the generic error 64 in one of my posts, some readers asked me if this is the ultimate reason for this error. The answer is: it is not! Since the error 64 is generic it needs to be carefully interpreted, my previous post about this error mentions the “error 64” with the message: “host not available”.

 

This post will explain in more details why the error message below showed in the ISA Server 2006 Logging could occur while you are browsing Internet.

 

Figure 1 – Another error 64.

 

The error above was caught while the user was trying to browse www.fabrikam.com and download the Windows XP SP2 file. To simulate this problem I used the following lab:

 

 

Figure 2 – Lab used to simulate this problem.

 

2. Understanding the nature of this error

 

The 64: "The specified network name is no longer available" is a win32 error originally called ERROR_NETNAME_DELETED, this error is mapped in the winerror.h as:

 

//

// MessageId: ERROR_NETNAME_DELETED

//

// MessageText:

//

//  The specified network name is no longer available.

//

 

In the network level, this problem could be cause by:

Network connectivity problems have various causes, but they typically occur because of incorrect network adapters, incorrect switch settings, faulty hardware, or driver issues. Some connectivity symptoms are intermittent and do not clearly point to any one of these causes.

Per KB325487.

 

Which means that is more under the TCP/IP level, which is controlled by the Windows OS rather than ISA Server itself.

 

3. Simulating the Problem

 

To simulate this problem I used a tool called Network Emulator for Windows and added high latency and random packet loss. Besides I also used the Web Application Stress Tool to add more load to my web server and really simulate a situation where server is busy. Now let’s take a look in the netmon trace got from the external interface of the ISA Server:

 

ISA Server sends the HTTP GET for the destination server:

12:39:13.355  192.168.1.113 192.168.1.95  HTTP   HTTP:Request, GET /

- Http: Request, GET /

    Command: GET

  + URI: /

    ProtocolVersion: HTTP/1.1

    Via:  1.1 ISACONTN1

    If-None-Match:  "304054985f13c91:4b2"

    UserAgent:  Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; SV1; .NET CLR 1.1.4322)

    Host:  www.fabrikam.com

    If-Modified-Since:  Wed, 10 Sep 2008 16:09:25 GMT

    Accept:  image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, */*

    Accept-Language:  en-us

    UA-CPU:  x86

    Connection:  Keep-Alive

    HeaderEnd: CRLF

 

Destination server sends the answer:

12:39:13.745  192.168.1.95  192.168.1.113 HTTP   HTTP:Response, HTTP/1.1, Status Code = 200, URL: /

 

A HTTP GET is sent to get the XP SP2 file:

12:39:31.751  192.168.1.113 192.168.1.95  HTTP   HTTP:Request, GET /XPSP2.zip

 

Destination server answers:

12:39:32.142  192.168.1.95  192.168.1.113 HTTP   HTTP:Response, HTTP/1.1, Status Code = 200, URL: /XPSP2.zip

 

The file starts to be transferred:

12:39:32.242  192.168.1.95  192.168.1.113 TCP    TCP:Flags=...A...., SrcPort=HTTP(80), DstPort=2050

 

12:39:32.242  192.168.1.113 192.168.1.95  TCP    TCP:Flags=...A...., SrcPort=2050, DstPort=HTTP(80)

 

Suddenly the destination server resets the connection:

12:39:32.424  192.168.1.95  192.168.1.113 TCP    TCP:Flags=.....R.., SrcPort=HTTP(80), DstPort=2050

 

12:39:32.584  192.168.1.95  192.168.1.113 TCP    TCP:Flags=.....R.., SrcPort=HTTP(80), DstPort=2050

 

At this point the session was lost and the error showed in figure 1 appeared in the log.  

 

4. Conclusion

 

What it is important for you after reading this post is to really understand that ISA Server for scenarios like this only externalize the problem. You need to focus on the real problem and start that by verifying:

·         Which device is in between ISA and Internet?

o   Don’t think that just because you have only a router in front of ISA Server that you will be “free of errors”. Routers do have updates and potential problems also.

·         Can you sniffer the outside traffic to have the real picture of what comes into your network before hits the external interface of ISA Server?

o   If you get the netmon trace only on the external interface of ISA and you have more devices in front of it you could be masquerading the real issue since you can’t see the clear traffic.

·         If ISA is really the edge device, make sure that network interface card is update, the switch where ISA is connected is working properly, etc.

o   Many administrators are only concern with updates on the OS level and forgot to address key updates do the drivers and active network devices.

 

Almost of the time the investigation of those errors occurs around ISA Server rather than in ISA Server itself. Keep your mind open to a broader set of possibilities instead of focus all our time and efforts in troubleshoot only ISA Server.

 

Comments
  • PingBack from http://www.keyongtech.com/3061046-ssl-vs-dmz

  • Hi Yuri

    Error 64 has been annoying me for a while - this might interest you

    http://bit.ly/hHcBsx

    Regards

    Jack

  • Thanks Jack, I will check it out !

  • Jack, thanks for the link, but we have the exact same setup as your solution (W2K8, 8GB RAM) and we are still getting Error 64.  Back to the drawing board.

  • I think this error may also occur if the http request has been initiated with a session which is not longer available / reachable. Of course the client still sends those requests and fails.

  • I have this issue with OWA publishing although i could reach my server with telnet www.adminkit.net/telnet.aspx on port 443 but OWA works some times and others down i think it might be a problem in ASA firewall.

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