Re: Wrong /24 Announcement at UU.net / BGP IOS Bug ?

[Jan Czmok]

Hi Vinny!

As i am thinking about this, i came to the idea that mostly uu.net applies filters
to their downstreams
e.g. there are not filtering by as - they filter by access-list
what i presume is that they use a

access-list xyz permit 151.189.0.0 255.255.255.0

instead of (the correct one):

access-list xyz permit 151.189.0.0 255.255.0.0

note the difference ?

It's probably time for them to call the uunet support to fix this.

Winfried Haug wrote:

> Hello..
>
> one of our customers (germany.net, AS6751) is announcing us
> 151.189.0.0/16. We announce this to our both upstreams
> ECRC (AS1273) and Ebone (1755).
>
> Since a few days a lot of german ISPs ask us, why 151.189.0.0/24
> is routed via UU.net to the USA and then goes back to germany.
>
> We checked our cisco-routers an finaly i found a Customer of UU.net
> with a looking glass: (http://zeus.lyceum.com/cgi-bin/nph-bgp-routes)
>
> > QUERY: bgp 151.189.0.0
> > FROM: BR1.ATL1.lyceum.net.
> >
> > BGP routing table entry for 151.189.0.0/24, version 9891827
> > Paths: (1 available, best #1, advertised over IBGP)
> >   701 1800 1755 1755 1755 5549 5549 6751
> >     157.130.64.121 from 157.130.64.121 (137.39.2.42)
> >       Origin IGP, valid, external, best
>
> ok lets see bacK:
>
> Sprint (1800) doesnt have this /24 but the /16 as it should be:
>
> icm-bb4-pen#show ip bgp 151.189.0.0 255.255.255.0
> % Network not in table
> icm-bb4-pen#
>
> the same applies to EBONE (AS1755):
>
> frankfurt-ebs1>show ip bgp 151.189.0.0 255.255.255.0
> % Network not in table
> frankfurt-ebs1>
>
> an we (AS5549) also dont see any /24 out of 151.189.0.0/16
>
> So the question is: why does UU.net announce 151.189.0.0/24 and from
> where do they get it. The worse thing is, that all uu.net customers get
> this )(&%&$()& /24 from the hub in Frankfurt. The Space
> 151.189.1.0 - 151.189.255.255 is visiable at uu.net via 151.189.0.0/16..
>
> So what happens here, could this be an ios bug ?
>
> We didnt touch our configuration towards ebone and they dont play
> with their configuration every day :-)
>
> Any ideas ? hints ?
>
> Winfried
>
> PS: for the german isps, we fixed it by announcing only at de-cix the
>     151.189.0.0/24 additionally to 151.189.0.0/16 and it works, but
>     i am still looking for an answer to my questions :-) ?
>
> --
>
> Winfried Haug    |        seicom.NET & SCHWABEN.DE       | Tel. +49 7121 9770- 0
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