Subject: Problems with wm interface and vlan's
To: None <email@example.com>
From: Chris Ross <firstname.lastname@example.org>
Date: 03/01/2005 23:59:22
I have an i386 machine running NetBSD 2.0.1. It is running almost
problem, but the network performance on it is pitiful!
I have a wm0, with no IP address on it.
I have 6 vlan interfaces (vlan0 - vlan5) each on wm0, with different
An scp from this machine (which is my router) to a host on a directly
attached network (via vlan1) starts at 200+ KB/s, but quickly drops down
to 30 KB/s. And, it'll flutter around, occasionally stall, and proceed
20-30 KB/s. This is silly.
I tried reconfiguring the machine to use fxp0 instead of wm0 as the
parent interface, and that works much better. The same test as above
gets 1.9+ MB/s consistently.
So, I have two questions:
1) When I use fxp0, the MTU of the vlan interfaces are 1500, just as
the mtu on fxp0. But, when I use wm0, I have to manually set the mtu
because if I don't, the MTU on the vlan interfaces comes up as 1496 when
they are created. Why is this different?
2) What can I do to test what the problem is with my wm0?
I looked at the Cisco switch it's hooked into (in both cases), and it
does report input errors from the wm. But, it doesn't indicate what
type they are. Can I get error counters from the card under NetBSD?
Could it be a software problem in the kernel, or is it a hardware
Thanks. Any help appreciated.