Re: bogus BGP annoucements - some thoughts for relief

[Philip Smith <]

Hi Kurt,

At 22:05 16/06/00 +0200, Kurt Kayser wrote:
> Hi,
>
> I'm trying to get rid of the section called
> 'Advertised IANA Reserved Addresses' in the
> 'RIPE NCC Region Weekly Routing Report'.
> <snip>
> If we want to try get some of this stuff out of the backbone and even 
> decrease some (unnecessary) BGP-traffic, why not publish a 'ingress 
> BGP-filterlist' that is endorsed by the RIPE-wg, RIPE or the community at 
> large?
How about http://www.ietf.org/internet-drafts/draft-manning-dsua-03.txt 
which is a very good start for a list which should be applied on all 
external BGP peerings (inbound and outbound). A draft I would certainly 
like to see as a BCP RFC.... Maybe this working group could consider 
something like this as a recommendation to "the community", like RIPE-210 
flap dampening parameters?

> What it basically does is:
>
> 1. Reject illegal prefixes (127/8, 0/0, RFC1918, etc.)
> 2. Log orginiators (if wanted)
> 3. Decrease SPAM-complaints
> 4. Prevent abuse
>
> It's low on CPU (it's no IP filter-list!), just a BGP-ingress filter.
I could post a Cisco prefix-filter list based on Bill Manning's draft, if 
that would help. It would certainly help with 1 and 2.

It may also be a service if ISPs with Cisco routers could apply "bgp neigh 
<x> remove-private-AS" on eBGP peerings so that origin private ASes 
(>64511) aren't leaked to the Internet.

> I have even added some prefix-length filter, but this is another topic,
> and depends on your upstream's policy. (I just can't stand /32s in the 
> table!).
Some ISPs go as far as filtering on the regional registries minimum 
allocation sizes, and the unused former A space. However, I think this 
needs a little more diligence in following changes in registry policy 
(APNIC recently moved from /19 to /20), any address space returned to the 
common pool, and any new /8s being allocated to registries for distribution 
purposes.

Happily the announcements are much cleaner this week (certainly from the 
view used in producing the weekly routing reports). This morning I only saw 
the attached.

philip
--

List of Illegal AS's (Global)
-----------------------------

Bad AS  Designation  Network              Transit AS  Description
64602   PRIVATE       63.236.57.0/24         209       Qwest
64601   PRIVATE       63.236.90.0/24         209       Qwest
64513   PRIVATE       200.12.17.0/24        6471       ENTEL CHILE S.A.
65014   PRIVATE       208.185.113.0/24      6461       AboveNet Communicati

Advertised IANA Reserved Addresses
----------------------------------

Network            Origin AS  Description
39.96.40.224/30      14408     iCAIR
65.56.64.0/21         2941     Community News Service

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Philip Smith                         ph: +61 7 3238 8200
Consulting Engineering, Office of the CTO, Cisco Systems
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