Re: arp flapping after udating system to 11-CURRENT.

From: Chris H <bsd-lists_at_bsdforge.com>
Date: Wed, 03 Feb 2016 09:36:24 -0800
On Wed, 3 Feb 2016 11:13:21 -0500 Allan Jude <allanjude_at_freebsd.org> wrote

> On 2016-02-03 10:32, Chris H wrote:
> > On Wed, 03 Feb 2016 06:55:47 -0800 "Chris H" <bsd-lists_at_bsdforge.com> wrote
> > 
> >> On Wed, 3 Feb 2016 08:31:43 +0100 Peter Ankerstål <peter_at_pean.org> wrote
> >>
> >>> Hi!
> >>>
> >>> I recently upgraded my system to 11-CURRENT (FreeBSD 11.0-CURRENT #0 
> >>> r295087: Sun Jan 31 10:21:31 CET 2016) and after that all of my other 
> >>> devices in the network complains about arp-flapping:
> >>>
> >>> arp: 172.25.0.1 moved from 00:00:24:d0:9e:5d to 02:e8:ea:15:66:00 on re0
> >>> arp: 172.25.0.1 moved from 02:e8:ea:15:66:00 to 00:00:24:d0:9e:5d on re0
> >>> arp: 172.25.0.1 moved from 00:00:24:d0:9e:5d to 02:e8:ea:15:66:00 on re0
> >>>
> >> FWIW I'm seeing this too. As it happened; I had just changed upstream
> >> providers, getting a larger static block (IP's), as well as updating
> >> my long overdue -CURRENT. So I simply blamed it on their (upstream)
> >> network. I'd love to get to the bottom of this, and would be happy to
> >> help.
> >>
> >> FreeBSD dev-box 11.0-CURRENT FreeBSD 11.0-CURRENT #0 r294112:
> >> Mon Jan 18 14:25:01 PST 2016 root_at_dev-box:/usr/obj/usr/src/sys/DEVBOX
> >> amd64 >>
> >> src is at Revision: 406193
> >>
> > Well, it would have helped if I had also mentioned that I'm not using
> > a bridge, and list the interfaces involved. :/
> > 
> > nfe0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
> > options=82008<VLAN_MTU,WOL_MAGIC,LINKSTATE>
> > 
> > This also occurs on my 9-STABLE boxes
> > re0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500  
> >
> >
options=8209b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,WOL_MAGIC,LIN
> > KSTATE> 
> > nfe0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
> > options=82008<VLAN_MTU,WOL_MAGIC,LINKSTATE>
> > 
> > nfe0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
> > options=82008<VLAN_MTU,WOL_MAGIC,LINKSTATE>
> > 
> > --Chris
> >>
> >>>
> >>> It seems to be flapping between the virtual mac of my bridge interface 
> >>> and the actual mac adress on the physical interface. This was not the 
> >>> case when i ran FreeBSD 10.2. Is there some settings I need to do?
> >>>
> >>>
> >>> bridge0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 
> >>> 1500
> >>>          description: wired <-> wifi bridge
> >>>          ether 02:e8:ea:15:66:00
> >>>          inet 172.25.0.1 netmask 0xffffff00 broadcast 172.25.0.255
> >>>          inet6 2001:470:de59::1 prefixlen 64
> >>>          inet6 fe80::2%bridge0 prefixlen 64 scopeid 0xb
> >>>          nd6 options=1<PERFORMNUD>
> >>>          groups: bridge
> >>>          id 00:00:00:00:00:00 priority 32768 hellotime 2 fwddelay 15
> >>>          maxage 20 holdcnt 6 proto rstp maxaddr 2000 timeout 1200
> >>>          root id 00:00:00:00:00:00 priority 32768 ifcost 0 port 0
> >>>          member: wlan2 flags=143<LEARNING,DISCOVER,AUTOEDGE,AUTOPTP>
> >>>                  ifmaxaddr 0 port 10 priority 128 path cost 66666
> >>>          member: wlan1 flags=143<LEARNING,DISCOVER,AUTOEDGE,AUTOPTP>
> >>>                  ifmaxaddr 0 port 9 priority 128 path cost 66666
> >>>          member: wlan0 flags=143<LEARNING,DISCOVER,AUTOEDGE,AUTOPTP>
> >>>                  ifmaxaddr 0 port 8 priority 128 path cost 22222
> >>>          member: em1 flags=143<LEARNING,DISCOVER,AUTOEDGE,AUTOPTP>
> >>>                  ifmaxaddr 0 port 2 priority 128 path cost 2000000
> >>>
> >>> em1: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> metric 0 
> >>> mtu 1500
> >>>          description: wired LAN
> >>>  
> >>> options=42098<VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,WOL_MAGIC,VLAN_HWTSO>
> >>>          ether 00:00:24:d0:9e:5d
> >>>          nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
> >>>          media: Ethernet autoselect (1000baseT <full-duplex>)
> >>>          status: active
> >>>
> >>>
> >>> /Peter.
> >>
> 
> Chris:
> If you are not using a bridge, please provide the complete output of
> ifconfig, and the log messages about the arp flapping, so we can see
> which two interfaces it is bouncing between.
> 
Thank you very much for the reply, Allan.
This is what I'm working with/experiencing:

Logs from just one of the offending boxes, the same is echoed in the
other boxes' logs, as well
Feb  3 08:04:48 udns kernel: arp: XX.YY.ZZ.85 moved from 00:24:81:ce:ba:87 to
00:17:10:8e:5e:87 on re0
Feb  3 08:05:58 udns kernel: arp: XX.YY.ZZ.83 moved from 40:61:86:cd:44:97 to
00:17:10:8e:5e:87 on re0
Feb  3 08:08:10 udns kernel: arp: XX.YY.ZZ.83 moved from 00:17:10:8e:5e:87 to
40:61:86:cd:44:97 on re0
Feb  3 08:13:00 udns kernel: arp: XX.YY.ZZ.84 moved from 00:17:10:8e:5e:87 to
00:30:67:5e:29:5d on re0
Feb  3 08:25:40 udns kernel: arp: XX.YY.ZZ.85 moved from 00:24:81:ce:ba:87 to
00:17:10:8e:5e:87 on re0
Feb  3 08:30:37 udns kernel: arp: XX.YY.ZZ.83 moved from 40:61:86:cd:44:97 to
00:17:10:8e:5e:87 on re0
Feb  3 08:36:05 udns kernel: arp: XX.YY.ZZ.84 moved from 00:30:67:5e:29:5d to
00:17:10:8e:5e:87 on re0
Feb  3 08:49:11 udns kernel: arp: XX.YY.ZZ.85 moved from 00:24:81:ce:ba:87 to
00:17:10:8e:5e:87 on re0
Feb  3 08:49:12 udns kernel: arp: XX.YY.ZZ.85 moved from 00:17:10:8e:5e:87 to
00:24:81:ce:ba:87 on re0
Feb  3 08:56:53 udns kernel: arp: XX.YY.ZZ.84 moved from 00:30:67:5e:29:5d to
00:17:10:8e:5e:87 on re0
Feb  3 09:09:09 udns kernel: arp: XX.YY.ZZ.84 moved from 00:17:10:8e:5e:87 to
00:30:67:5e:29:5d on re0
Feb  3 09:09:30 udns kernel: arp: XX.YY.ZZ.85 moved from 00:24:81:ce:ba:87 to
00:17:10:8e:5e:87 on re0
Feb  3 09:16:41 udns kernel: arp: XX.YY.ZZ.83 moved from 40:61:86:cd:44:97 to
00:17:10:8e:5e:87 on re0

11-CURRENT on r294112, from r406193 src:
nfe0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
	options=82008<VLAN_MTU,WOL_MAGIC,LINKSTATE>
	ether 00:24:81:ce:ba:87
	inet XX.YY.ZZ.85 netmask 0xffffff00 broadcast XX.YY.ZZ.255 
	inet6 fe80::224:81ff:fece:ba87%nfe0 prefixlen 64 scopeid 0x1 
	nd6 options=23<PERFORMNUD,ACCEPT_RTADV,AUTO_LINKLOCAL>
	media: Ethernet autoselect (1000baseT <full-duplex>)
	status: active

9-STABLE:
re0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
	options=8209b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,WOL_MAGIC,LINKSTATE>
	ether 40:61:86:f6:aa:2a
	inet XX.YY.ZZ.81 netmask 0xffffff00 broadcast XX.YY.ZZ.255
	inet6 fe80::4261:86ff:fef6:aa2a%re0 prefixlen 64 scopeid 0x1 
	nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
	media: Ethernet autoselect (1000baseT <full-duplex>)
	status: active

9-STABLE:
nfe0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
	options=82008<VLAN_MTU,WOL_MAGIC,LINKSTATE>
	ether 40:61:86:cd:44:97
	inet XX.YY.ZZ.83 netmask 0xffffff00 broadcast XX.YY.ZZ.255
	inet6 fe80::4261:86ff:fecd:4497%nfe0 prefixlen 64 scopeid 0x3 
	nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
	media: Ethernet autoselect (100baseTX <full-duplex>)
	status: active

9-STABLE:
nfe0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
	options=82008<VLAN_MTU,WOL_MAGIC,LINKSTATE>
	ether 00:30:67:5e:29:5d
	inet XX.YY.ZZ.84 netmask 0xffffff00 broadcast XX.YY.ZZ.255
	inet6 fe80::230:67ff:fe5e:295d%nfe0 prefixlen 64 scopeid 0x3 
	nd6 options=23<PERFORMNUD,ACCEPT_RTADV,AUTO_LINKLOCAL>
	media: Ethernet autoselect (100baseTX <full-duplex>)
	status: active

Topography:
boxes --> switch --> router --> internet

Thanks again!

--Chris
> -- 
> Allan Jude
Received on Wed Feb 03 2016 - 16:35:49 UTC

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