VERY strange ssh (and other network) behavior

Nimue · 2011-03-20 04:57:19

Okay, so let me set this up for you. I have a server, right? Seemingly randomly, I cannot access it locally. However, I *CAN* access it remotely on a constant basis.

What happens is if I try to access it locally, it ends up timing out. However, if I ssh in remotely and ping the computer I'm trying to reach it from, it will drop several of the initial packets, THEN it will suddenly "see" the local computer. Basically, here's a scenario:

Computer A tries to access Computer B
Fail

Computer A tries to ping Computer B
Fail

Computer A uses remote access to access the SAME computer B, but bouncing off of dyndns.
Success!

Computer A tries to ping the router from Computer B
Success!

Computer A now tries to ping itself from Computer B on the local network
First couple packets are dropped, then the ping suddenly works.

Computer A tries to access Computer B on the local network
Success!

This applies to ssh, my air video server, and any other service. I have also verified this over several computers and iOS devices.

My hosts.deny is blank.

Thoughts?

toad · 2011-03-20 07:10:39

A router issue? Perhaps faulty switches? What is your local setup?

cactus · 2011-03-20 19:53:39

Try setting 'UseDNS no' in the server sshd_config.
See if that makes a difference. It *may* help... but given the ping issue.... maybe not.

As to the ping issue..that is quite odd. I agree with toad that you may want to look at your switching layer. There could be a device between the hosts that has bad ram (switch might not be storing the MAC to switchport references correctly) and it takes a few arps to get it right again. Another possibility could be a switching loop maybe?

Nimue · 2011-03-22 18:32:38

I'm not sure. There are other computers that can access other servers on the network just fine.

If it helps, I am using wpa_supplicant on the host computer.

arch_gala · 2011-03-23 12:05:41

firewall on the sshd computer is probably not setup properly.

you need to define the allowed hosts on 'hosts.allow' with a line like 'ssh:192.168.' .

Nimue · 2011-03-23 16:30:04

arch_gala wrote:

firewall on the sshd computer is probably not setup properly.
you need to define the allowed hosts on 'hosts.allow' with a line like 'ssh:192.168.' .

I have that, actually.

Arch Linux

#1 2011-03-20 04:57:19

VERY strange ssh (and other network) behavior

#2 2011-03-20 07:10:39

Re: VERY strange ssh (and other network) behavior

#3 2011-03-20 19:53:39

Re: VERY strange ssh (and other network) behavior

#4 2011-03-22 18:32:38

Re: VERY strange ssh (and other network) behavior

#5 2011-03-23 12:05:41

Re: VERY strange ssh (and other network) behavior

#6 2011-03-23 16:30:04

Re: VERY strange ssh (and other network) behavior

Board footer