re(4) vlan issue

["Chris Brookes" <cbrookes%gmail.com@localhost>]

I'm having an issue with re(4) and vlans. My system is a Athlon X2
BE-2350 and a GIGABYTE GA-MA69VM-S2 mobo. I am running a kernel under
amd64 compiled from
http://ftp.netbsd.org/pub/NetBSD-daily/HEAD/200803080000Z/source/sets/syssrc.tgz.

re0 at pci2 dev 15 function 0: RealTek 8169SC/8110SC Single-chip
Gigabit Ethernet (rev. 0x10)
re0: interrupting at ioapic0 pin 23, event channel 13
re0: Ethernet address 00:1a:4d:ff:e4:72
re0: using 256 tx descriptors
rgephy0 at re0 phy 7: RTL8169S/8110S/8211 1000BASE-T media interface, rev. 2

When the interface was brought up with a regular IP it worked without
issue. When I brought up re0 without an IP and instead configured a
vlan interface with the other end connected to a 801.1q trunk port on
my switch, things started to go awry.

I could source traffic from the box and get as far as installing
packages over the network seemingly without problems, but strangely
inbound traffic wasn't working properly. An inbound telnet on port 22
to the box would produce the SSH banner, but any subsequent traffic
would vanish. Looking at a trace in wireshark it showed a successful
tcp connection setup (obviously since I saw the banner) but after the
banner there'd be a couple of retransmissions and then nothing. I
plugged in an old  3c905 and using the ex driver every thing's fine on
the system.

I discovered PR 32643 which seemed pretty similar and so I went ahead
and commented out the VLAN hardware tagging code for the re driver.
Sure enough with that commented out, my issue goes away. My maximum
MTU is reduced to 1496, but other than that everything works well.

I discovered PR 37959 which is probably related though the PR lacks
enough detail to be sure.

I note there is a user on FreeBSD with an re(4) on amd64 who is also
experiencing some problems.

http://lists.freebsd.org/pipermail/freebsd-current/2008-February/083584.html

I don't know whether that's related but the thread is interesting reading.

Regards

Chris