em promiscuous mode bug?
Pyun YongHyeon
pyunyh at gmail.com
Mon Jul 31 05:43:52 UTC 2006
On Mon, Jul 31, 2006 at 07:16:03AM +0200, Ian FREISLICH wrote:
> Pyun YongHyeon wrote:
> > On Tue, Jul 25, 2006 at 08:07:04AM +0200, Ian FREISLICH wrote:
> > > Hi
> > >
> > > It seems that placing an em(4) interface into promiscuous mode the
> > > card stops doing hardware offload of 802.1Q tagging, in fact, it
> > > stops tagging entirely if vlanhwtag is enabled on the card.
> > >
> > > With vlanhwtag:
> > > 15:40:48.050645 00:00:5e:00:01:02 > 01:00:5e:00:00:12, ethertype IPv4 (0x0
> 800), length 70: (tos 0x10, ttl 255, id 44821, offset 0, flags [DF], proto: VRR
> P (112), length: 56) 196.30.82.61 > 224.0.0.18: VRRPv2, Advertisement, vrid 2,
> prio 10, authtype none, intvl 1s, length 36, addrs(7): 157.248.206.115,76.246.4
> 2.167,148.235.231.80,70.180.123.113,201.169.28.232,19.31.18.203,59.148.50.175
> > >
> > > Without vlanhwtag:
> > > 15:40:57.419522 00:00:5e:00:01:02 > 01:00:5e:00:00:12, ethertype 802.1Q (0
> x8100), length 74: vlan 1001, p 0, ethertype IPv4, (tos 0x10, ttl 255, id 44867
> , offset 0, flags [DF], proto: VRRP (112), length: 56) 196.30.82.61 > 224.0.0.1
> 8: VRRPv2, Advertisement, vrid 2, prio 10, authtype none, intvl 1s, length 36,
> addrs(7): 157.248.206.115,76.246.42.176,8.148.142.115,171.178.137.11,211.216.40
> .239,67.124.122.122,253.155.32.152
> > >
> > > The interface is placed in promiscuous mode by the carp driver.
> > >
> > > em0: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500
> > > options=cb<RXCSUM,TXCSUM,VLAN_MTU,POLLING,VLAN_HWCSUM>
> > > ether 00:04:23:cf:50:00
> > > media: Ethernet autoselect (1000baseTX <full-duplex>)
> > > status: active
> > >
> > > vlan1001: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1
> 500
> > > inet 196.30.82.62 netmask 0xfffffff0 broadcast 196.30.82.63
> > > ether 00:04:23:cf:50:00
> > > media: Ethernet autoselect (1000baseTX <full-duplex>)
> > > status: active
> > > vlan: 1001 parent interface: em0
> > >
> > > carp1001: flags=49<UP,LOOPBACK,RUNNING> mtu 1500
> > > inet 196.30.82.60 netmask 0xfffffff0
> > > carp: BACKUP vhid 2 advbase 1 advskew 0
> > >
> >
> > Hardware VLAN tagging was disabled in em(4) when it operates
> > in promiscuous mode and em(4) will insert a VLAN tag in the
> > driver.
>
> Um, no. When an em interface with hardware VLAN tagging enabled
> is placed in promiscuous mode, it just _stops_ tagging. Entirely.
> The 802.1Q vlan just breaks.
>
Would you try latest em(4) in CURRENT?(if_em.c, rev. 1.122)
> Ian
>
> --
> Ian Freislich
--
Regards,
Pyun YongHyeon
More information about the freebsd-current
mailing list