Liniux 'ping' Problem

[chez]

I am currently experiencing a problem whereby a Linux box cannot ping a server which a Windows XP box, plugged into the exact same cable/port etc, can ping.

Here is how our network is configured -



The ISA Server has 3 NICs, one connected to the internal domain, one for the DMZ and one external interface.

We have an exchange server internally, with an Exchange bridgehead in the DMZ (to allow the complex routing/header re-writes that we require).

As we cannot plug the external connection in until the system has received security accreditation, I am hoping to use the Linux box (plugged into the external interface of the firewall) as an external SMTP server (using sendmail) to test our Exchange routing.

Here's the problem:

- I can ping the Linux laptop from the Exchange bridgehead.

- I cannot ping the Exchange bridgehead from the Linux laptop.

- If I replace the Linux laptop with an XP laptop (using the same IP and network settings), I can ping the Exchange bridgehead from the laptop (which, in my mind, rules out the network itself and the firewall as an issue).

The domain is Server 2003. The Linux box is running Suse and has Webmin and sendmail installed.

We have opened up the Firewall completely, but this made no difference.

I am a bit of a n00b when it comes to Linux, so any help/advice welcomed

Thanks in advance
Richard

[TheAnimus]

on the linux box, can you ping its IP on the network?

[Moby-Dick]

I'd be thinking about name resolution too... Linux boxes can't register themselves in DNS can they ?

if its on a static IP then add the mapping to your DNS manually , if its on a dynamic mapping then configure your DHCP box to register clients that can't register themselves.


are you using the FQDN to ping the server ? Is local DNS set up ok ?

[chrestomanci]

Most linux distros ship with a firewall by default. It might be blocking the outbound ping, or the reply from the Exchange bridgehead.

Webmin includes a firewall administration module. If the module is installed it should be easy to view & change the firewall setup.

[chez]

I'm in the middle of something else and will check out the things mentioned and reply in a while, but name resolution is not the problem.

An external server would not use our internal domain DNS.

I am pinging by IP address on both machines (XP/Linux), not hostname, so DNS should be irrelevant..?

[javalord]

I'm in the middle of something else and will check out the things mentioned and reply in a while, but name resolution is not the problem.

An external server would not use our internal domain DNS.

I am pinging by IP address on both machines (XP/Linux), not hostname, so DNS should be irrelevant..?

What about the switches? VLAN configs would be first thing I'd check.

I take it you can ping other linux boxes?

[yamangman]

Are you sure you're using the ping program correctly?