FreeBSD 4.9 losing mbufs!!!

[Stephen Clark]

Hello List,

I know 4.9 is ancient history, but unfortunately we have several 
thousand sites installed. We are in the process of moving to 6.1 when it 
is released.

Right now I have an immediate problem where we are going to install two 
system at a
HQ site. Each of the 2 systems will have two gre/vpn/ospf tunnels to a 
100 remote sites in the
field. The broadband will be a T3 with failover to dialup actiontec 
dualpc modems. We want
to use FreeBSD systems rather than put in Cisco equip which is what we 
have done for other
large customers.

The problem:

I have been testing between an Athlon 64 3000+ (client)  and an Athlon 
64 X2 4800+ (server) across a dedicated 100mb lan. When I use nttcp, 
which is a round trip tcp test, across the gre/vpn the client system, 
(which goes to 0 percent idle), network stack will eventually stop 
responding. In trying to track this down I find that   
net.inet.ip.intr_queue_maxlen which is normally 50 has been reached (I 
added a sysctl to be able to look at it), but it never drains down. If I 
increase it things start working again. If I continue to hammer the 
client I see the
intr_queue_maxlen continue to grow until it again reaches the new 
maximum. Another datapoint if I don't send the data thru the gre tunnel, 
but only thru the vpn I don't see this problem.

I've looked at the gre code til I am blue in the face and can't see 
where mbufs  were not being freed when the quelen is full.

If anybody could give some direction as where to look or how to better 
trouble shoot this problem it would be greatly appreciated.

Thanks for being such a great list,
Steve

-- 

"They that give up essential liberty to obtain temporary safety, 
deserve neither liberty nor safety."  (Ben Franklin)

"The course of history shows that as a government grows, liberty 
decreases."  (Thomas Jefferson)