Bug 137089 - [lagg] lagg falsely triggers IPv6 duplicate address detection
Summary: [lagg] lagg falsely triggers IPv6 duplicate address detection
Status: Open
Alias: None
Product: Base System
Classification: Unclassified
Component: kern (show other bugs)
Version: Unspecified
Hardware: Any Any
: Normal Affects Only Me
Assignee: freebsd-net (Nobody)
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2009-07-24 19:40 UTC by xelah-freebsdpr
Modified: 2018-05-28 19:49 UTC (History)
2 users (show)

See Also:

Attachments
Add an attachment (proposed patch, testcase, etc.)

Note You need to log in before you can comment on or make changes to this bug.
Description xelah-freebsdpr 2009-07-24 19:40:01 UTC 
When an IPv6 alias is added to a lagg interface one duplicate address detection ICMP neighbour solicitation message is sent from each interface forming the link. The kernel then thinks that the address is a duplicate when it isn't. This does not happen when only one physical interface is being used.

Fix: 

Not really a fix, of course:

[root@db2 /usr/home/alex]# ifconfig lagg1 inet6 fda8:48b8:b52c:3::b prefixlen 120 -alias
[root@db2 /usr/home/alex]# ipfw add 50 deny icmp6 from any to any
00050 deny ipv6-icmp from any to any
[root@db2 /usr/home/alex]#
[root@db2 /usr/home/alex]# ifconfig lagg1 inet6 fda8:48b8:b52c:3::b prefixlen 120 alias
[root@db2 /usr/home/alex]# ipfw delete 50
[root@db2 /usr/home/alex]#
[root@db2 /usr/home/alex]# ifconfig lagg
lagg1: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        options=9b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM>
        ether 00:15:60:0a:4d:9a
        inet6 fe80::214:38ff:fe51:5da0%lagg1 prefixlen 64 scopeid 0x6
        inet 10.10.10.11 netmask 0xffffff00 broadcast 10.10.10.255
        inet6 fda8:48b8:b52c:1::b prefixlen 120
        inet6 fda8:48b8:b52c:3::b prefixlen 120
        media: Ethernet autoselect
        status: active
        laggproto lacp
        laggport: bge1 flags=1c<ACTIVE,COLLECTING,DISTRIBUTING>
        laggport: bge3 flags=1c<ACTIVE,COLLECTING,DISTRIBUTING>
How-To-Repeat: [root@db2 /usr/home/alex]# jobs
[2]-  Running                 tail -f /var/log/messages &
[3]+  Running                 tcpdump -vnpi lagg1 icmp6 &
[root@db2 /usr/home/alex]# ifconfig lagg1
lagg1: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        options=9b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM>
        ether 00:15:60:0a:4d:9a
        inet6 fe80::214:38ff:fe51:5da0%lagg1 prefixlen 64 scopeid 0x6
        inet 10.10.10.11 netmask 0xffffff00 broadcast 10.10.10.255
        inet6 fda8:48b8:b52c:1::b prefixlen 120
        media: Ethernet autoselect
        status: active
        laggproto lacp
        laggport: bge3 flags=1c<ACTIVE,COLLECTING,DISTRIBUTING>
[root@db2 /usr/home/alex]#
[root@db2 /usr/home/alex]#
[root@db2 /usr/home/alex]# ifconfig lagg1 inet6 fda8:48b8:b52c:3::b prefixlen 120 alias
[root@db2 /usr/home/alex]#
[root@db2 /usr/home/alex]# 19:06:54.716072 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 24) :: > ff02::1:ff00:b: [icmp6 sum ok] ICMP6, neighbor so
licitation, length 24, who has fda8:48b8:b52c:3::b

[root@db2 /usr/home/alex]#
[root@db2 /usr/home/alex]#
[root@db2 /usr/home/alex]# ifconfig lagg1
lagg1: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        options=9b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM>
        ether 00:15:60:0a:4d:9a
        inet6 fe80::214:38ff:fe51:5da0%lagg1 prefixlen 64 scopeid 0x6
        inet 10.10.10.11 netmask 0xffffff00 broadcast 10.10.10.255
        inet6 fda8:48b8:b52c:1::b prefixlen 120
        inet6 fda8:48b8:b52c:3::b prefixlen 120
        media: Ethernet autoselect
        status: active
        laggproto lacp
        laggport: bge3 flags=1c<ACTIVE,COLLECTING,DISTRIBUTING>


[root@db2 /usr/home/alex]# ifconfig lagg1 inet6 fda8:48b8:b52c:3::b prefixlen 120 -alias
[root@db2 /usr/home/alex]# ifconfig lagg1 laggport bge1
[root@db2 /usr/home/alex]# ifconfig lagg1
lagg1: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        options=9b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM>
        ether 00:15:60:0a:4d:9a
        inet6 fe80::214:38ff:fe51:5da0%lagg1 prefixlen 64 scopeid 0x6
        inet 10.10.10.11 netmask 0xffffff00 broadcast 10.10.10.255
        inet6 fda8:48b8:b52c:1::b prefixlen 120
        media: Ethernet autoselect
        status: active
        laggproto lacp
        laggport: bge1 flags=1c<ACTIVE,COLLECTING,DISTRIBUTING>
        laggport: bge3 flags=1c<ACTIVE,COLLECTING,DISTRIBUTING>
[root@db2 /usr/home/alex]# ifconfig lagg1 inet6 fda8:48b8:b52c:3::b prefixlen 120 alias
[root@db2 /usr/home/alex]# 19:12:04.364760 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 24) :: > ff02::1:ff00:b: [icmp6 sum ok] ICMP6, neighbor so
licitation, length 24, who has fda8:48b8:b52c:3::b
19:12:04.364826 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 24) :: > ff02::1:ff00:b: [icmp6 sum ok] ICMP6, neighbor solicitation, length 24, who
has fda8:48b8:b52c:3::b
Jul 24 19:12:05 db2 kernel: lagg1: DAD detected duplicate IPv6 address fda8:48b8:b52c:3::b: NS in/out=1/1, NA in=0
Jul 24 19:12:05 db2 kernel: lagg1: DAD complete for fda8:48b8:b52c:3::b - duplicate found
Jul 24 19:12:05 db2 kernel: lagg1: manual intervention required
[root@db2 /usr/home/alex]# ifconfig lagg1
lagg1: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        options=9b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM>
        ether 00:15:60:0a:4d:9a
        inet6 fe80::214:38ff:fe51:5da0%lagg1 prefixlen 64 scopeid 0x6
        inet 10.10.10.11 netmask 0xffffff00 broadcast 10.10.10.255
        inet6 fda8:48b8:b52c:1::b prefixlen 120
        inet6 fda8:48b8:b52c:3::b prefixlen 120 duplicated
        media: Ethernet autoselect
        status: active
        laggproto lacp
        laggport: bge1 flags=1c<ACTIVE,COLLECTING,DISTRIBUTING>
        laggport: bge3 flags=1c<ACTIVE,COLLECTING,DISTRIBUTING>
Comment 1 Mark Linimon freebsd_committer freebsd_triage 2009-07-25 02:08:36 UTC 
Responsible Changed
From-To: freebsd-bugs->freebsd-net

Over to maintainer(s).
Comment 2 Hiren Panchasara freebsd_committer freebsd_triage 2015-01-29 03:50:09 UTC 
Is this still an issue? Is anybody running into this?
Comment 3 xelah-freebsdpr 2015-01-29 08:54:10 UTC 
(In reply to Hiren Panchasara from comment #2)

The servers involved have long since been retired, so I no longer have a way to test if it still happens.
Comment 4 Eitan Adler freebsd_committer freebsd_triage 2018-05-28 19:49:06 UTC 
batch change:

For bugs that match the following
-  Status Is In progress 
AND
- Untouched since 2018-01-01.
AND
- Affects Base System OR Documentation

DO:

Reset to open status.


Note:
I did a quick pass but if you are getting this email it might be worthwhile to double check to see if this bug ought to be closed.