pptp + bird

[Ondrej Zajicek]

On Fri, Aug 10, 2012 at 02:45:18PM +0200, Amadeus wrote:
> b) it is also present in birdc:
> > show interfaces
> ppp5 up (index=923)
> PtP Multicast AdminUp LinkUp MTU=1446
> 169.254.0.1/32 (Primary, opposite 169.254.40.52, scope univ)
> 
> c) the interface has been rescanned by bird as ppp5:
> 10-08-2012 11:17:30 <TRACE> static1 < interface ppp5 goes up
> 
> d) routes are missing (table 100 = kffc):
> # ip r s table 100 dev ppp5
> <no output>

Also could you check and send me what says 'show static' for that route
in that situation?

> -- What happended before --
> DOWN event:
> 10-08-2012 11:18:38 <TRACE> static1 > removed [sole] 10.8.129.32/28 via
> 169.254.40.52 on ppp2
> 10-08-2012 11:18:38 <TRACE> kffc < removed 10.8.129.32/28 via
> 169.254.40.52 on ppp2
> 10-08-2012 11:18:38 <TRACE> static1 > removed [sole] 10.8.131.48/28 via
> 169.254.40.52 on ppp2
> 10-08-2012 11:18:38 <TRACE> kffc < removed 10.8.131.48/28 via
> 169.254.40.52 on ppp2
> 
> When I look at the timestamps it seems as if the old interface is not
> down before the new one comes up which means that bird won't be able to
> set the new routing information as it is still present on the old
> interface, does that make sense to you? Is there any trigger in bird to
> catch that or do I have to set scan device >>60s?

Generally, if the new iface with the same address prefix appears before
the 'old' prefix that definitely could cause the problem - when the
'old' prefix is removed, ther route is also removed ignoring that the
prefix is already on another iface.

I thought about this possibility before but it seemed strange that it would
happen on ppp connections, i guess that the reconnect would need some
time between disconnect and new connect, so the 'old' prefix would be removed
before the 'new one' would be added.

The scan device interval shouldn't matter much - interface and prefix changes
are announced immediately and the scanning is here only for verification and
catching missed notifications. So the question is whether the appearance of
'new' prefix before removing of 'old' prefix is just on BIRD level (e.g. if
announcements were missed for some reason and both changes were catched by scan)
or also on OS level (e.g. if old PPP session was not properly terminated
so new PPP session was established before the old one timeouted).

Could you also send me more complete part of logfile, i.e. containing everything
related to the reconnect, both interfaces down and up and prefixes removal and
adding?

-- 
Elen sila lumenn' omentielvo

Ondrej 'SanTiago' Zajicek (email: santiago at crfreenet.org)
OpenPGP encrypted e-mails preferred (KeyID 0x11DEADC3, wwwkeys.pgp.net)
"To err is human -- to blame it on a computer is even more so."
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