Problem w/ 3620 config

[m.egan]

Hello,

I have small lab environment and recently starting experiencing problems connecting to some internet sites. The setup is as follows.

ISP-DSLMODEM-3620(e0/0)-3630(fa1/0)-2900XL-PC.

The e0/0 int gets a dynamic ip addres from ISP.

I'm running static and dynamic NAT with overloading. Initially the config worked great. Then I started testing IDS when I reaized I could now longer get to sites like Microsoft.com and Msnbc.com. Once I realized this I backed off the IDS config. There were a few CRC errors on e0/0 so I changed cables and reloaded the router. No more CRC errors but those sites still won't come up. I connected the DSL modem to a PC and, of course everything works fine. So before I blowout my configs I thought I'd ask for some ideas. Thanks and Happy New Year.

[spremkumar]

hi

can u pls clarify whether u r trying out with an external ids system or with ids configs in the 3620 box itself ?if yes with 3620 box then do post the config part of tht..

regds

[m.egan]

Thanks for the reply.

I was using IDS configs within the 3620 itself. I got so frustrated with the performance that I blew away the config. Then configured a very basic NAT connection to the internet and I'm still experiencing problems. Browsing some sites are slow and others don't even load. But most seem fine. I can't seem pin point the problem. Recent I took all other components out of the picture so the diagram would have been this...

dslmodem->3620(e0/0)-3630(fa1/0)->laptop(w/cross-over). So it's just the router and the modem and the pc.

[spremkumar]

hi

hv u tried connecting ur laptop directly to the DSL modem and chekd up the speed ?

as u said some of the sites arent opening ,chek them by loggin onto the router and clear the ip nat translations first then try to access those sites and chek whether any translation is happening or not..tht would help u out to find out the reason.

and as u said the browsin is slow whts the benchmark ur using to compare the speed with this setup ??

regds

[tjeanne]

I already had this problem with DSL connections using PPPoE. Some web sites worked correctly but some others ones were unreacheable. I solved it modifying MTU parameters.

A tech note is available about this problem on http://www.cisco.com/warp/public/794/router_mtu.html .

Maybe it will help you to solve your problem.

Regards,

Tanguy

[egain.com]

There may be a problem with DNS name resolution. ..regards

[m.egan]

Thanks,

I'll try lowering the mtu. It's already at 1492 but it may need to be lowered. Attached is a copy of my config.