ND/5/ND_CONFIG_CONFLICT: NS INTERVAL is not consistent.

[Anonymous]

Hello,

my switch is constantly logging the error in the subject line every 3 minutes. It seems to have something todo with Neighbour Discovery. I have 10 VLANs with route advertisement enabled and IPv6 is working perfectly fine in these

VLANs.

(infra) [/var/adm/syslog/2014/01/05] grep ND_CONFIG_CONFLICT local3 | tail
Jan  5 21:45:48 merlin %%10ND/5/ND_CONFIG_CONFLICT(l):  NS INTERVAL is not consistent.
Jan  5 21:48:49 merlin %%10ND/5/ND_CONFIG_CONFLICT(l):  NS INTERVAL is not consistent.
Jan  5 21:51:26 merlin %%10ND/5/ND_CONFIG_CONFLICT(l):  NS INTERVAL is not consistent.
Jan  5 21:53:54 merlin %%10ND/5/ND_CONFIG_CONFLICT(l):  NS INTERVAL is not consistent.
Jan  5 21:57:04 merlin %%10ND/5/ND_CONFIG_CONFLICT(l):  NS INTERVAL is not consistent.
Jan  5 21:59:59 merlin %%10ND/5/ND_CONFIG_CONFLICT(l):  NS INTERVAL is not consistent.
Jan  5 22:02:44 merlin %%10ND/5/ND_CONFIG_CONFLICT(l):  NS INTERVAL is not consistent.
Jan  5 22:05:59 merlin %%10ND/5/ND_CONFIG_CONFLICT(l):  NS INTERVAL is not consistent.
Jan  5 22:08:36 merlin %%10ND/5/ND_CONFIG_CONFLICT(l):  NS INTERVAL is not consistent.
Jan  5 22:11:48 merlin %%10ND/5/ND_CONFIG_CONFLICT(l):  NS INTERVAL is not consistent.
(infra) [/var/adm/syslog/2014/01/05] grep ND_CONFIG_CONFLICT local3 | wc -l
460

Cheers,

      Thomas

[Anonymous · Accepted solution]

Hello,

I filed a bugreport with HP. They told me that the error message indicates that another router is sending router advertisements creating incosistencies between the two advertisements. So I started sniffing on the h3c device:

acl ipv6 number 3999 name icmp6
        rule permit icmpv6
        rule deny ipv6
        quit
packet capture start acl ipv6 3999 length 1500 buffer-size 2048 mode linear
display packet capture status
packet capture stop
packet capture buffer save nd.pcap
scp 10.10.10.1 put nd.pcap
reset packet capture buffer
undo packet capture

 Waited for the next log message and correlated the entry of a log message to the following advertisement:

420 13:50:01.742000 fe80::222:bdff:fed6:c14a -> ff02::1      ICMPv6 122 Router Advertisement from 00:22:bd:d6:c1:4a

 I followed the mac and found a cisco asa. The cisco asa does route advertisements by default, so I disabled it using:

interface vlan 99
   ipv6 nd suppress-ra

 Afterwards the route advertisements and the log messages were gone. HP could be a little bit more verbose over

the VLAN and the mac address of the offending device.

Cheers,

     Thomas