bgp soft reconfiguration inbound

Wolfgang Hennerbichler wh at
Tue Dec 1 10:48:56 CET 2009

On Nov 30, 2009, at 21:18 , Ondrej Zajicek wrote:

>> ...
> I checked the source for the loop check and it seems that there are some
> problems in that code.


> Second, in some situations the loop check does not work and that causes
> that the first problem manifests less often :-).

allright :)

>> protocol pipe P30971x30x15 {
>>  table T30971x30;
>>  mode transparent;
>>  peer table T5403x15;
>>  import filter { reject; };
>>  export filter {
>>    if from = then {
>>      accept;
>>    }
>>    else reject;
>>  };
>> }
> All your pipes do reject in the import filter and relevant test in the export
> filter?

all my pipes look exactly like this, without any exceptions. 

> Every route passes through at most one pipe according to your expected
> filter behavior?

well, a route can be distributed from one table to let's say 10 other tables by 10 pipes. you remember we do things a little different. but the pipes are set like above. so there can't be a triangle or something that sends routes from table A, to table B, to table C and back to A. That shouldn't be possible.

>> Do the pipes ignore the filters at any time? 
> I think filters are not ignored.

ok. I think it's the loop prevention thing that's in place before the filter which causes this, this is very certain. I also checked quite some routes where bird thinks they're looping, and all of them are where they should be. Are there chances you'll fix the loop checking code so that it at least checks always after filtering?

>> PS: We've got BIRD running at VIX in Beta now, about 12 participants,
>> no crashes, no problems at all (except for the loop notices)
> That is nice.

I think so, too :) 

> -- 
> Elen sila lumenn' omentielvo
> Ondrej 'SanTiago' Zajicek (email: santiago at
> OpenPGP encrypted e-mails preferred (KeyID 0x11DEADC3,
> "To err is human -- to blame it on a computer is even more so."

-- |
wh at | WH844-RIPE
Vienna University Computer Center

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