Having issues with bridging vlan and em in 5.4-STABLE

Jonathan Feally vulture at netvulture.com
Sat Oct 8 23:20:43 PDT 2005

I'm trying to setup a machine that will be both routing traffic and 
bridging 2 segments of one network with ipfw processing on that bridged 
network. The routing seems to be OK and bridging is also OK from Side to 
side, however when trying to talk to the IP of the machine from another 
machine on the bridged network i am seeing packet loss.


em0   x.y.199.254 connected to segment with outgoing router at 
x.y.199.1. Lets call this Side A
em1   no IP. Internal interface with all the vlans attached to it
vlan199  no IP configured as tagged vlan 199 attached to em1. We'll call 
this Side B.
10 more vlans configured with IP's for the routing portion. No packet 
loss in the routed scenario.

em0 and vlan199 are bridged

Host at x.y.199.101 connected to Side B can reach all hosts connected to 
Side A except for the bridging machine
Using nslookup on .101 to .254 as a test, tcpdump on vlan199 shows 
packets in from .101 to .254 and the returning packets from .254 to 
.101. em0 does not show any packets in or out. However packets are not 
being returned to the .101 host.
IPFW is not a culprit here as I have tried it with ipfw add 1 allow ip 
from any to any.

Moving the IP of .254 from em0 to vlan199 results in the same packet 
loss execpt on the Side A now.

Not all traffic from Side B to .254 and back is lost. dhcp and icmp do 
seem to be working. I am leaning towards an issue with BIND, however it 
does bother me that tcpdump sees packets leaving vlan199.

Anybody have any ideas?? Thanks in advance.


More information about the freebsd-net mailing list