On Thu, Mar 29, 2007 at 02:18:30AM -0400, Kyle George wrote: > On Wed, 28 Mar 2007, Watson Crick wrote: > > >I've got OpenBSD 4.0 (release) on a laptop setup up as a router between > >2 subnets, and providing internet access through a 3rd nic to a DSL > >modem. The problem is the bandwidth between the two subnets. I'm only > >getting a maximum of about 500 KB/s between two 100mbit cards. Top shows > >~70% interrupt (~29% idle) while these transfers are going on. I don't > >know what the bottleneck is in the system. Are the Linksys PCMCIA nics > >crappy? Did I screw something else up? > > Try http://www.openbsd.org/faq/faq6.html#Tuning. > > Increase net.inet.tcp.{send,recv}space. > > Try this before worrying about your hardware. >
The send and receive socket buffer space has nothing to do with forwarding performance. This will only affect connections from and to the box itself. I think the bigger problem are the PCMCIA nics. PCMCIA is a slow bus comparable to ISA and most PCMCIA cards are evil old clones of already terrible MAC chips. Also check the duplex mode -- autonegotiation can fail with older cards. -- :wq Claudio
