Onew Way Ping

[Guest_imported]

We have two networks, 194.153.29.x and 10.10.x.x. We have a Windows NT Server machine doing the routing between the two. This machine is running service pack 6a, It has two network cards in, one on the 194.153.29.x network and one on the 10.10.x.x network. Each card has the other card as the default gateway. IP forwarding and BOOTP are both enabled.

There is another router on our network which is our internet gateway. This routers IP address is 194.153.29.1. It has a static route on it which routes all traffic for the 10.10.x.x network back to the WINNT 4 routing machine. This router is the default gateway for all 194.153.29.x machines.

All the machine in both networks can ping each other. However no 10.10.x.x machine can ping our exchange server.

The exchange server is running Windows 2000 with service pack 2 and exchange 5.5 (we have an identical machine elsewhere in the office that can be pinged) with the following set-up.

IP Address : 194.153.29.2
Subnet mask: 255.255.255.0
Default Gateway 194.153.29.1

This exchange server can ping any 10.10.x.x machine. 10.10.x.x machines cannot ping the exchange server. However, if you reboot the exchange server the 10.10.x.x. machine will be able to ping it for a short period of time (between 8 and 20 replies). As the windows splash screen appears the ping fails. All 194.153.29.x machines can ping the exchange server.

All 10.10.x.xd machines are running windows 2000.

To resolve this issue we have attempted the following.

1) Re-installed TCPIP on the Exchange server.
2) Re-applied windows 2000 service pack 2 on the exchange server
3) Re-installed network card on exchange server.
4) Checked all cables are connected.
5) Disabled all exchange services
6) Stopped each service possible individually on the exchange server

 

[gurner]

This may sound a bit daft, but when you say you have 2 identical Exchange machines they dont have identical IP addresses do they?

Also your 10.10.x.x machines appear to be on a different subnet to the 194.153.29.x machines. But this shouldnt really be an issue, i beleive if the IP forwarding is enabled (would this be both ways?).

 

[GlenJohnson]

Use your monitor to make sure you don't have a network card sending out bad packets. I had one go bad on a server, and when my users tried to log in after a couple of hours of the server being up, they got a "wrong password or user id". When I finally figured out that something had to be changing over the course of time, I monitored for bad packets on the server. When I re-booted the server, the bad packets weren't to bad, but it kept getting worse to the point that the added network traffic wouldn't let the users log on. I changed the nic and never had a lick of problem again. The nic doesn't need to be on the server. Any piece of equipment with a bad network card could be flooding the network with bad packets, causing confusion. Good luck. Glen A. Johnson
Microsoft Certified Professional

"All things are difficult before they are easy."
Thomas Fuller (1608 - 1661) English scholar, preacher.