>> A while back I was having networking issues. I eventually tried
>> drastically lowering the MTU of all the systems onsite and the issues
>> disappeared. I always thought the issue was due to the MTU on our
>> modem/router. Today I read that AT&T DSL requires a 1492 MTU so I
>> increased the MTU of our systems up to 1492 and haven't had any
>> issues. Do certain ISPs require you to change the MTU of your entire
>> network, or is this likely due to our AT&T modem/router itself?
> Are you using tunnels or a firewall that blocks related "icmp
> fragmentation needed" packets?
I have this in shorewall/rules:
ACCEPT all all icmp - - - 10/sec:20
Which I believe accepts all icmp packets but throttles them to 10/sec
to avoid being flooded. Is that OK?
> Please also try to find out if you're experiencing packet loss. If
> fragmented packets cannot be reassembled due to some packets lost, you
> will probably find connections freezing or going really slow.
I will watch the output of ifconfig today to see if there are any RX
or TX errors.