r288951: ifconfig -alias, arp not removed

[Alexander V. Chernikov]

30.10.2015, 00:57, "Bryan Drewery" <bdrewery at FreeBSD.org>:
> On 10/29/2015 9:46 AM, Bryan Drewery wrote:
>>  On 10/29/15 9:42 AM, Eric van Gyzen wrote:
>>>  On 10/29/2015 11:25, Bryan Drewery wrote:
>>>>  # ifconfig
>>>>  igb0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
>>>>
>>>>  options=403bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,TSO4,TSO6,VLAN_HWTSO>
>>>>          ether c8:0a:a9:04:39:78
>>>>          inet 10.10.0.7 netmask 0xffff0000 broadcast 10.10.255.255
>>>>          inet 10.10.7.2 netmask 0xffff0000 broadcast 10.10.255.255
>>>>          inet 10.10.0.9 netmask 0xffff0000 broadcast 10.10.255.255
>>>>          nd6 options=23<PERFORMNUD,ACCEPT_RTADV,AUTO_LINKLOCAL>
>>>>          media: Ethernet autoselect (1000baseT <full-duplex>)
>>>>          status: active
>>>>
>>>>  # ifconfig igb0 inet 10.10.0.9 -alias
>>>>  # arp -an|grep 10.10.0.9
>>>>  ? (10.10.0.9) at c8:0a:a9:04:39:78 on igb0 permanent [ethernet]
>>>>  # arp -d 10.10.0.9
>>>>  arp: writing to routing socket: Operation not permitted
>>>>
>>>>  I swear this is not normal. I'm on an older build as well, r288951.
Well, there were changes on arpscrub procedures in r287789.
(There was one bug fixed in r289501, but I think it is not relevant).
Could you consider trying more recent HEAD and check if this is still reproducible?
I was not able to reproduce that behavior.
>>>
>>>  That definitely looks abnormal. See what "route get" says. I think
>>>  that's the error you get when there is a route for that address.
>>
>>  # netstat -rn|grep 10.10.0.9
>>  # route get 10.10.0.9
>>     route to: lapbox
>>  destination: 10.10.0.0
>>         mask: 255.255.0.0
>>          fib: 0
>>    interface: igb0
>>        flags: <UP,DONE,PINNED>
>>   recvpipe sendpipe ssthresh rtt,msec mtu weight expire
>>         0 0 0 0 1500 1 0
>>  # route get 5.5.5.5
>>     route to: 5.5.5.5
>>  destination: default
>>         mask: default
>>      gateway: router.asus.com
>>          fib: 0
>>    interface: igb0
>>        flags: <UP,GATEWAY,DONE,STATIC>
>>   recvpipe sendpipe ssthresh rtt,msec mtu weight expire
>>         0 0 0 0 1500 1 0
>>
>>  For more context, this current system had 10.10.0.9 added to it. I
>>  started up a VM which also started using 10.10.0.9 and managed to "win"
>>  on the local network for owning it. (I don't know arp and this stuff
>>  well). I then came to this system to remove the alias and the arp entry
>>  to allow me to connect from it and have gotten into this situation.
>
> Just saw this in dmesg, which is what I described:
>
> arp: 08:00:27:12:c1:a5 is using my IP address 10.10.0.9 on igb0!
> arp: 08:00:27:12:c1:a5 is using my IP address 10.10.0.9 on igb0!
> arp: 08:00:27:12:c1:a5 attempts to modify permanent entry for 10.10.0.9
> on igb0
> arp: 08:00:27:12:c1:a5 attempts to modify permanent entry for 10.10.0.9
> on igb0
> arp: 08:00:27:12:c1:a5 attempts to modify permanent entry for 10.10.0.9
> on igb0
> arp: 08:00:27:12:c1:a5 attempts to modify permanent entry for 10.10.0.9
> on igb0
>
> --
> Regards,
> Bryan Drewery