Another routing question for a PC with 2 NICs

[FastEddieC]

I know there are already 2 other recent posts on this subject, but my situation is a little different.

When I first installed the 2nd NIC, I posted the problems I encountered here:

http://www.tek-tips.com/viewthread.cfm?qid=1006195&page=1

- which was solved by adding a persistent "route add" statement. (thanks again!)

We recently changed our ISP, which caused this PC to have a problem getting to the internet. I figured "no problem - just remove the old “route add” statement and put in a new “route add” statement Which worked - sort of. We can ping a web address but the response time is anywhere from 2000 - 4000. So if I use a web browser, it will time-out long before a response comes back. On a standard PC (with one NIC) the response to the internet is very quick (40ms)

I have a theory, I believe the problem is: The PC is connected to two networks, and when the user requests an internet site, it asks the primary gateway (fails), then it goes through the other card and asks the gateway that I manually put in with the “route add” command, which means it goes to our DNS server (windows 2003), - which looks on our network (fails), so it goes to the address I have setup as a “Forwarder” which is our ISP... then it reaches it’s destination.

Like I said, this is only a theory, because I have no way of tracking the data packets. (I do have Ethereal packet sniffer, but I’m not sure how I could identify this particular traffic flow from all the rest).

I also tried to flush the dns & re-register it - but that didn’t help.

Anyone have any ideas?
Did I make sense in my description?

Thanks in advance,


Eddie

 

[DTracy]

Try using the Tracert program and display the results here. Just open a command window and type tracert xxx.xxx.xxx.xxx (which is the IP of your ISP) and press the enter key. This will give you a look at the route used to your ISP and any hops needed.

BR
David Tracy

 

[PalmTest]

When using Windows XP you can also use pathping xxx.xxx.xxx.xxx to see where the biggest delay occurs.

 

[FastEddieC]

I'm not familiar with "pathping", it seems to act more like "tracert" than "ping". - neat...
Anyway, I tried both commands on a working PC first before trying it on the problem PC. Since I have a Cisco firewall seperating me from my ISP, tracert to the ISP's servers doesn't show any results. Similarly, pingpath shows my PC, then the router, then times out - because the next step is the router.
On the problem PC - I recieved no results using either command. I'll tinker with somemore when the user can give me access to it.

 

[PeterHurst]

Traceroute and Pathping may not show you the problem if it is as you describe (I suspect so)

The delay will cause the utilities to pause too.

If possible take out the default gateway in the other card to stop the unknown traffic using it. If this works you can try putting it back but with a higher metric (2 or 3) to make it a lower priority.

If this doesn't work, take it out and put statics in to the networks that appear on that card using route add but use the /p switch to make them permanent.