Re: wm(4) and VLANs

[Thor Lancelot Simon <tls%panix.com@localhost>]

On Fri, May 25, 2012 at 03:22:20PM +0100, Stephen Borrill wrote:
> 
> However, DHCP requests come on both the vlan and parent interface:
> May 25 15:00:06 netmanager dhcpd: DHCPDISCOVER from d0:23:db:3b:b2:d2 via 
> vlan400
> May 25 15:00:06 netmanager dhcpd: DHCPOFFER on 192.168.2.196 to 
> d0:23:db:3b:b2:d2 via vlan400
> May 25 15:00:06 netmanager dhcpd: DHCPDISCOVER from d0:23:db:3b:b2:d2 via wm0
> May 25 15:00:06 netmanager dhcpd: DHCPOFFER on 10.0.10.56 to 
> d0:23:db:3b:b2:d2 via wm0

Why is the switch upstream from you handing you untagged frames at all?
Why does your port have a default VLAN set so that outbound untagged
frames are accepted and forwarded?  Both seem to be the case, and both are
configuration errors on the upstream switch.

AFAICT dhclient does not know how to look past the VLAN encapsulation
with which the frames would appear on wm0 if they were actually sent
tagged -- a strong hint of this is that you are not *also* seeing the
DHCPOFFER for the 192.168.2/24 network on wm0, though if you looked with
tcpdump, you would find it, VLAN tagging and all.

Thor