Date: Tue, 27 Jan 2009 12:39:26 -0500 From: Mike Tancsa <mike@sentex.net> To: freebsd-net@freebsd.org Subject: lagg failover mode and vlans Message-ID: <200901271739.n0RHdGd3047497@lava.sentex.ca>
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Hi,
I noticed a small issue with the way VLANs work and the
lagg0 interface in failover mode.
I have a simple config of
ifconfig lagg0 create up laggproto failover laggport em2 laggport em3
192.168.44.99/24
ifconfig lagg0.100 create 192.168.100.1/24
ifconfig lagg0.102 create 192.168.102.1/24
with em2 on one cisco 3500 and em3 on another cisco 3500 (primary and
secondary) on port 32 of each switch
interface FastEthernet0/32
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1-200,1002-1005
switchport mode trunk
spanning-tree portfast
!
interface FastEthernet0/32
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1-200,1002-1005
switchport mode trunk
spanning-tree portfast
!
and the switches are linked together with
interface GigabitEthernet0/2
switchport trunk encapsulation dot1q
switchport mode trunk
!
On the freebsd RELENG_7 box
lagg0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
options=19b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,TSO4>
ether 00:30:48:90:4c:fe
inet 192.168.44.99 netmask 0xffffff00 broadcast 192.168.44.255
media: Ethernet autoselect
status: active
laggproto failover
laggport: em3 flags=0<>
laggport: em2 flags=5<MASTER,ACTIVE>
For the native vlan of 1, if I pull the cable on the master port
fa0/32, it works automatically and I barely miss a packet
lagg0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
options=19b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,TSO4>
ether 00:30:48:90:4c:fe
inet 192.168.44.99 netmask 0xffffff00 broadcast 192.168.44.255
media: Ethernet autoselect
status: active
laggproto failover
laggport: em3 flags=4<ACTIVE>
laggport: em2 flags=1<MASTER>
but if I create some vlan interfaces off lagg0
lagg0.100: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
options=3<RXCSUM,TXCSUM>
ether 00:30:48:90:4c:fe
inet 192.168.100.1 netmask 0xffffff00 broadcast 192.168.100.255
media: Ethernet autoselect
status: active
vlan: 100 parent interface: lagg0
lagg0.102: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
options=3<RXCSUM,TXCSUM>
ether 00:30:48:90:4c:fe
inet 192.168.102.1 netmask 0xffffff00 broadcast 192.168.102.255
media: Ethernet autoselect
status: active
vlan: 102 parent interface: lagg0
and do the same pulling of the cable, it does not work. BUT, if I do
an arp -nda on a machine that is part of vlan102 which is doing the
pinging (so an arp-who has gets sent out and a reply answered), it
works. The other option is if I send a packet out on the vlan's
broadcast address from the server
Apart from making a script to watch for interface up/down events on
the machine with the lagg0 interface and vlans to do ping to each of
the broadcast addresses, is there a way around this ?
There was a discussion sort of around this in
http://unix.derkeiler.com/Mailing-Lists/FreeBSD/net/2008-05/msg00283.html
---Mike
--------------------------------------------------------------------
Mike Tancsa, tel +1 519 651 3400
Sentex Communications, mike@sentex.net
Providing Internet since 1994 www.sentex.net
Cambridge, Ontario Canada www.sentex.net/mike
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