dhcpcd-discuss

Oops, I sent a link to the wrong router. It is a different one from
Swisscom. It uses fibre. It is definitely not the analog one. They all look
the same. Possible it is this one or a variant of it:

http://www.swisscom.ch/en/residential/more/save-energy/router-centro-grande-adb-pirelli.html


On Mon, Jun 2, 2014 at 5:52 PM, Lode <olifant@xxxxxxxxx> wrote:

> It is the following router from the ISP. I'm not sure what make is behind
> it:
> http://www.swisscom.ch/de/privatkunden/internet/internet-zuhause/devices/centro-grande-analog-standard.html
>
> Other devices (an Ubuntu laptop, and an Android phone) seem to work fine
> with it: they get both an IPv4 and an IPv6, which is visible in the UI of
> the router.
>
> This is all pretty standard afaik, so I would be inclined to say that the
> router is ok. Would it be worth investigating if it is a potential bug in
> dhcpcd? My own knowledge at this level of networking is unfortunately not
> that high though, so other than providing more details I can't be of much
> help.
>
> The OS of my desktop is Archlinux, which uses systemd, which is the one
> that goes crazy from receiving so much logging (constant HD activity).
> Currently I'm getting more worried about the actual ipv6 problem than the
> logging :)
>
> Regards,
>
> -Lode
>
>
> On Mon, Jun 2, 2014 at 10:47 AM, Roy Marples <roy@xxxxxxxxxxxx> wrote:
>
>> Hi
>>
>>
>> On 01/06/2014 11:36, Lode wrote:
>>
>>> Unless I disable noipv6rs, dhcpcd will write the following to the
>>> syslog every few seconds:
>>>
>>> eth0: invalid prefix in RA
>>> ipv6nd_handlera: Success
>>>
>>
>> Here is the code which logs this error
>>
>>                 if (IN6_IS_ADDR_MULTICAST(&pi->nd_opt_pi_prefix) ||
>>                     IN6_IS_ADDR_LINKLOCAL(&pi->nd_opt_pi_prefix))
>>                 {
>>                         syslog(LOG_ERR,
>>                             "%s: invalid prefix in RA", ifp->name);
>>                         break;
>>                 }
>>
>> As you can see, the prefix you are being asked to add a route for is
>> either a multicast or linklocal prefix, both of which are invalid.
>> So it's the sending router that is at fault here.
>>
>>
>>  Writing to the log so much (every few seconds) causes a lot of
>>> nuisance, including obscuring other log messages and causing constant
>>> disk writes so that the disk never rests.
>>>
>>
>> This is true.
>> At most I could move the logging from an error condition to a debug
>> condition.
>>
>>  In addition, I did not find a solution to fix "invalid prefix in RA"
>>> and what the actual root cause is. Nothing in my system is broken so
>>> it might be a non-issue. The best reference on the internet I found is
>>> this post, in which they also have no real clue:
>>> https://bbs.archlinux.org/viewtopic.php?id=139302 [1]
>>>
>>>
>>> So I have two requests:
>>>
>>> -Is it possible to avoid writing to the log so often please? If the
>>> message is in there once, it would be sufficient.
>>>
>>
>> See above about moving it to a debug condition.
>> The problem of "just the once" means I have to start remembering faulty
>> routers.
>>
>>
>>  -What is the actual problem of "invalid prefix in RA", and how to fix?
>>> Does it not like my router? It seems to be in ipv6nd.c.
>>>
>>
>> No, it doesn't like your router.
>> An advertised prefix cannot be a linklocal or multicast one, which your
>> router is sadly advertising.
>> For reference, can you state the make and model of your router please?
>>
>> Thanks
>>
>> Roy
>>
>>
>