[Cerowrt-devel] frequency of RAs from 6relayd

Michael Richardson mcr at sandelman.ca
Wed Jun 12 13:14:50 EDT 2013

I am seeing a problem where the IPv6 default on a number of systems
that use RA to get it is going away on a regular basis.  CeroWrt 3.8 is
the source of RA and IPv6 default routes everywhere.  A /48 is delegated
(manually) from my ISP, and configured for each subnet.

There is no way that I can see to specify or find out what the lifetime
/ frequency of the RAs are in the UI.  In /etc/config/6relayd, I see: 

config server 'default'
        option rd 'server'
        option compat_ula '1'
        option always_assume_default '1'
        option fallback_relay 'ndp'
        list network 'VoIP'
        list network 'gw00'
        list network 'gw01'
        list network 'gw10'
        list network 'gw11'
        list network 'se00'
        list network 'services'
        list network 'sw00'
        list network 'sw10'
        list network 'trusted'

It is my understanding that 6relayd is responsible for sending out RAs.

On my desktop:

obiwan-[~] mcr 10187 %sudo rdisc6 eth0
Soliciting ff02::2 (ff02::2) on eth0...

Hop limit                 :    undefined (      0x00)
Stateful address conf.    :          Yes
Stateful other conf.      :          Yes
Router preference         :       medium
Router lifetime           :         1800 (0x00000708) seconds
Reachable time            :  unspecified (0x00000000)
Retransmit time           :  unspecified (0x00000000)
 Source link-layer address: 76:44:01:76:5D:CC
 MTU                      :         1500 bytes (valid)
 from fe80::7444:1ff:fe76:5dcc

(5dcc is indeed my CeroWRT)

while the router lifetime given is 30 minutes, I am wondering if
something else is up.  I would have thought I'd see a prefix advertised

As my MP3 streamer one of the machines affected, when it loses it's IP, 
it either falls off of NFS or the TCP stream breaks, and things go

I've ssh'ed into my MP3 server (over v4), and I'm running:
     watch ip -6 route ls
and  sudo tcpdump -i eth0 -n -p ip6 and icmp6   
in two windows.

]               Never tell me the odds!                 | ipv6 mesh networks [ 
]   Michael Richardson, Sandelman Software Works        | network architect  [ 
]     mcr at sandelman.ca  http://www.sandelman.ca/        |   ruby on rails    [ 

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