[OpenAFS] MTU size -- don't set using both -maxmtu and ifconfig, at least under Solaris 9

Kim Kimball dhk@ccre.com
Tue, 21 Apr 2009 15:44:35 -0600


 From the "shoot yourself in the foot" department ...


We had some small issues trying to configure AFS file servers for 
correct functioning with a firewall, and -maxmtu 1260 finally fixed the 
problem, as it used to for older versions of Cisco VPN software on 
Windows.   [Which is why I thought of it, thank you Mr. Altman]

After getting things working I moved data onto the fileserver behind the 
firewall. 

Of numerous Solaris 9 clients that connect via VPN and run antique cache 
managers (3.6 2.53) -- only two failed to function correctly. 

The two that failed to function either timed out when accessing volumes 
on the fileserver in question, or succeeded after lengthy delays.

Cause:

fileserver -maxmtu 1260
ifconfig bge0 mtu 1260

This may be immediately obvious to others, but it was the last place I 
looked.

Once I reset the bge0 interface to mtu 1500 everything started working.

I can't say I understand the interaction, but thought mentioning it 
might help someone somewhere sometime.

Cheers.

Kim