NEtbios over TCP/ip not working

[jdedon]

I just replaced a 3660 with a 3745 running 12.3(6)a.

I have a server that communicates to a remote server using a network share. The originating server crosses a pix firewall and picks up the global PAT address before it reaches the 3660 and then crosses a T1 to the remote site. Everything was working fine for at least a year until I replace the 3660 with the 3745. There is no nat done on the router.

If I create the share and try to do a directory listing, it will sometimes complete the listing, and other times it will stop in the middle with file not found or share no longer available. I solved this problem by implementing a one to one NAT translation on the firewall. I have heard of some problems with netbios support over nat with low end cisco routers, but never with the higher end stuff. Why should the router care at this point anyway, it is not performing the nat and it should have no knowledge of the nat, right? Any ideas?

[scottmac]

Are you using IP Helper? or do you have a mapping on the host/local browser that points to a WINS server on the other segment (or vice versa)?

With the exception of some encryptions, NAT should not be an issue, IIRC.

Did you change the type or priority of NbT (broadcast versus WINS versus using files / LMHosts)?

Is netbeui enabled on either side (or both)?

Check it out and let us know ...

Scott

[jdedon]

No IP helper. What I have is a unc path from a windows 2000 server to a remote windows 2000 server.

The UNC is to an \\ip address\share name. No WINs server should be needed. No netbeui on either side. Ip only. The source server connects to the share by first traversing a local pix firewall where it picks up the global pat address for the DMZ where there is a 3745 router with no special configuration. Nothing but IP running on the router. All static routes. The traffic enters on an ethernet port on the router and exits the router on a serial T1 connection. The traffic enters on a serial T1 on the remote end and then crosses another pix firewall. This has worked fine until the 3660 died. I cut and pasted the serial configuration and the static routes onto the 3745 and then the share became unstable. I remembered having a simialr problem with another connection on this router where I had go back to the local firewall and make the source server of a netbios over tcp/ip connection a one to one nat. I assumed at the time that it had something to do with the size of the filesystem on the remote end. Large directories, millions of files on that file system. Anyway, the one to one nat at the firewall solved the problem. This file system is not that large.

[scottmac]

The only thing that comes to mind then is to maybe do a "clear XLATE" (clear the translation table) on the Pix(es) in case the new MAC / destination of the (newley added) router is causing some issue with the previously established link information.

I've seen a few occasions where a clear xlate has resolved off-the-wall issues.

Other than that, your setup appears to be pretty straight forward. Hopefully someone else has seen this and can throw out some more suggestions.

Good luck!

Scott

[jdedon]

That might be worth a shot, except the first time I saw this situation was when I added a new T1 to this router that connected a remote share that had previously been working without going through a firewall and di not involve nat. It broke when I added the pat translation.(no previous xlate or route for that matter). I solved it by a one to one nat on the firewall.

Still Stumped