Subject: Fun with bridge(4)
To: NetBSD tech-net mailing list <>
From: Julian Coleman <>
List: tech-net
Date: 03/16/2003 13:55:56
Thought I'd try out bridging.  I've noticed a few funnies with it.  Config
is two interfaces le0 and le1 in the bridge group.  le0 has IPv4 address and alias  le0 is configured without an IPv4
address.  Default route is (the only box behind le1).

  With IPv6, 30 seconds after the bridge is configured up, the machine stops
  transmitting IPv6 packets.  Configuring ipf on the bridge stops the
  trasmission instantly (no, I'm not blocking it in my ipf6 rules!).

  ipf sees packets from machines on the network as inbound
  on le1 (they came in on le0).

  I thought I'd try out IPNAT (mapping addresses on to  I was suprised that it almost worked.  Entries appeared in
  the mapping list and outbound packets were visible on le1.  The inbound
  replies didn't generate a packet on le0 though.  Also, the machines' own address was translated, stopping communication with machines

Apart from this, it seems to be fine with IPv4 and ipf.


PS.  sparc 1.6P (built roughly 10 March)

                    My other computer also runs NetBSD