strange network behaviour

[Duane Winner]

ben at stonehenge-net.com wrote:

>on Friday i set up 4 old celeron boxes as DNS servers for a client.  after
>about 5 minutes, their ability to reach the network vanishes... they can't
>ping their router, and inbound network traffic vanishes.  rebooting fixes
>the problem... for another ~ 5 min.
>
>the only things running are chrooted bind, postfix, and webmin.  ipfw is
>on, with firewall_type="open".  i've also tried it with ipfw disabled.
>
>The same thing happens with my laptop, which is also running 5-STABLE as
>of about noon on friday.
>
>I know this sounds like a network issue, but is there anything in the
>system that might cause thist type of behavior?  it doesn't seem to be the
>hardware - my laptop is a pentium M centrino system with a bg nic, and
>they're old Celeron 500 machines with fxp nics.
>
>  
>
I believe something happenend out there in DNS land around noon on 
Friday...on the root servers possibly? I've been struggling with slow 
SSH and SSL connections that started around that time, and when I've 
posted, others have reported similar things...all starting around noon 
on Friday. AFAIK, something happened that affected reverse DNS 
lookups...on the machines on which I was able, I could fix SSH by 
setting "UseDNS no" in sshd_config. Today, I cured all the slowness (I 
think so far) by adding in-addr.arpa zones for my internal 10.x.x.x 
subnets.