Performance/lockup issues with FreeBSD as a router

[Charles Swiger]

On May 26, 2005, at 1:47 PM, Peter Kieser wrote:
> The nics are if_dc, this is a stock FreeBSD 5.4-RELEASE  
> installation (no
> firewall or anything):
>
> Here's my /etc/sysctl.conf:
>
> net.inet.ip.rtexpire=1800
> net.inet.ip.rtminexpire=1800
> kern.maxfiles=32768
> kern.maxfilesperproc=32768
> kern.ipc.somaxconn=32767
> net.inet.tcp.sendspace=256000
> net.inet.tcp.recvspace=256000
> kern.ipc.maxsockbuf=2097152
> net.inet.ip.fastforwarding=1
> net.inet.tcp.rfc1323=1
> net.link.ether.inet.max_age=600
> net.inet.tcp.msl=7500
> net.inet.ip.fw.dyn_udp_lifetime=10
> net.inet.ip.fw.dyn_buckets=1024
>
> And here's my /boot/loader.conf:
>
> kern.ipc.maxsockets="163840"
> kern.maxusers="2048"
>
> Is there anythign I'm overlooking that would be causing the machine  
> to lockup
> like this?

Your settings are tuned so high that you may be running out of KVA  
memory.  I bet the system would be happier if you let maxusers  
autotune itself (and then maybe adjust it by a factor of 2 from  
there), and if you reduced kern.maxfilesperproc to 2048 or less, and  
reduced the TCP sendspace to 65K.

[ As a last resort, you might even try nixing the fastforwarding  
option.  It's well-suited for your task, and you do want it on if it  
is working right, but maybe try running without it for a test. ]

-- 
-Chuck