Date: Wed, 12 Mar 2008 22:22:34 +0100 From: Giulio Ferro <auryn@zirakzigil.org> To: Sam Leffler <sam@errno.com> Cc: freebsd-net@freebsd.org, Andrew Thompson <thompsa@FreeBSD.org> Subject: Re: VLAN trunking and fragmentation Message-ID: <47D8499A.5070605@zirakzigil.org> In-Reply-To: <47D817D2.9010306@errno.com> References: <47D7C34E.8060805@zirakzigil.org> <47D817D2.9010306@errno.com>
next in thread | previous in thread | raw e-mail | index | archive | help
Sam Leffler wrote:
> You failed to provide the output of ifconfig on your running system.
> Be sure any checksum offload is disabled (should be by the bridge).
>
> Sam
My bad.
I switched off checksum offload in /etc/rc.conf like this:
ifconfig_re0="inet 192.168.60.1 netmask 255.255.255.0 -rxcsum -txcsum"
(same thing on the other machine)
Now my ifconfig on PC #1 is :
-----------------------------------------
# ifconfig re0
re0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
options=98<VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM>
ether 00:14:c1:40:c2:e8
inet 192.168.60.1 netmask 0xffffff00 broadcast 192.168.60.255
media: Ethernet autoselect (1000baseTX <full-duplex>)
status: active
# ifconfig vlan0
vlan0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
ether 00:14:c1:40:c2:e8
inet 192.168.100.1 netmask 0xffffff00 broadcast 192.168.100.255
media: Ethernet autoselect (1000baseTX <full-duplex>)
status: active
vlan: 10 parent interface: re0
-----------------------------------------
on PC #2 :
-----------------------------------------
# ifconfig re0
re0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
options=98<VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM>
ether 00:15:8a:00:48:80
inet 192.168.60.2 netmask 0xffffff00 broadcast 192.168.60.255
media: Ethernet autoselect (1000baseTX <full-duplex>)
status: active
# ifconfig vlan0
vlan0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
ether 00:15:8a:00:48:80
inet 192.168.100.2 netmask 0xffffff00 broadcast 192.168.100.255
media: Ethernet autoselect (1000baseTX <full-duplex>)
status: active
vlan: 10 parent interface: re0
-----------------------------------------
Any packet greater than 1472 which gets fragmented doesn't pass through:
command : ping -c 1 -s 1473 192.168.100.2
on the sending machine:
-----------------------------------------
# tcpdump -i re0 -n -vvv not tcp and not stp
23:11:07.649600 IP (tos 0x0, ttl 64, id 399, offset 0, flags [+], proto
ICMP (1), length 1500) 192.168.100.1 > 192.168.100.2: ICMP echo request,
id 19972, seq 0, length 1480
23:11:07.649605 IP (tos 0x0, ttl 64, id 399, offset 1480, flags [none],
proto ICMP (1), length 21) 192.168.100.1 > 192.168.100.2: icmp
-----------------------------------------
Whereas on the receiving machine I don't get any packet.
Thanks for your answer.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?47D8499A.5070605>