Re: FreeBSD 12.3-p5: problems vnet on if_bridge

Tue, 24 May 2022 17:17:19 +0200 - FreeBSD User <freebsd@walstatt-de.de>:

> > could you solve the problem? I think I ran into the same problem.
> > I opened a Ticket.  
> 
> I couldn't solve the problem.
> 
> > 
> > https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=264198
> > 
> > I seems to be related to IPFW and effects vnet-Jails and also bhyve
> > VMs.  
> 
> There is also a PR regarding vnet/if_bridge/routing issues, at
> 
> https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=240106
> 
> but I can not guarantee this PR is in any way similaror adjacent to
> the problem of mine (and probably yours).

Difficult to say if the problems are related. In my problem IPFW plays
a role. 

Are you using IPFW? If so, please take a look at the issue
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=264198
I described very simple setup to reproduce the bug, in a Bhyve VM with
only one Interface:

vtnet0---bridge0---epaira0---epairb0

vm # ifconfig bridge create mtu 1400
vm # ifconfig epair create mtu 1400
vm #  ifconfig bridge0 addm epair0a
vm # ifconfig bridge0 addm vtnet0
vm # ifconfig epair0a up
vm # ifconfig epair0b inet <IP_ADDR>/28 mtu 1400 up
vm # ifconfig bridge0 up
vm # nc -v -l 2222 > /dev/null

the only IPFW rule is
vm # ipfw list
65535 allow ip from any to any

from another host (in the same network) I send data with nc:
dd if=/dev/zero bs=1024k count=6 | nc -v <IP_ADDR> 2222

result:
6291456 bytes transferred in 70.693446 secs (88996 bytes/sec)

after 'service ipfw stop' on vm-a, it is about 700 times faster )-:
6291456 bytes transferred in 0.100673 secs (62493675 bytes/sec)


I wonder if IPFW + bridge is broken in 12.3. ...