Bogon list

David McGaugh david_mcgaugh at eli.net
Wed Jun 5 00:29:07 UTC 2002


Tweaking our Looking Glass software by itself would not fix the problem
(ours doesn't have this problem anyway). To fix the problem everyone
would have to tweak their Looking Glass software since the problem can
be seen when someone traceroutes from a peer or 3rd party's Looking
Glass into our customer (in the event they weren't receiving the IXP
blocks from us).

One better might be to have the Looking Glass participating routers
manipulate their source IP address for pings and traceroutes.

Cisco:
Router(config)#ip traceroute source-interface ?
% Unrecognized command
Hmmm...

Router(config)#ip ping source-interface ?
% Unrecognized command
Hmmm...

Juniper:
[edit]
Router# set system default-address-selection
Hey that works!

Is there a way of doing this on a Cisco?

-Dave

"Sean M. Doran" wrote:
> 
> | While on the subject of IXP blocks, we also ended up redistributing the
> | IXP blocks and sending them to our BGP customers (who do not receive a
> | default) so that traceroutes and such from Looking Glasses do not break.
> | They can then choose to filter them as they wish.
> 
> This is backwards.  Do not break the architecture to fix a broken
> looking glass (or to work around bad interpretations of real-world
> traceroute results).   Spend a few minutes scripting your looking
> glass software so that if it sees a well-known target, or an expected
> real-world result (1918 addresses that YOU are using, with expected
> ttl-distance), it returns a "sanitized" result to a naive
> looking glass user.
> 
> I wonder if there exists the possibility of a useful (perhaps open source)
> generalized expert system to interpret traceroute data?
> "configure; make; make install" is probably even easier than
> breaking one's filter lists to leak prefixes all over the place.
> 
>         Sean.  (that was a hint.  you know who you are.)

-- 
------------------------------------------
 Dave McGaugh, Internetwork Engineer
 Electric Lightwave, Inc.
 E-mail: dmcgaugh at eli.net
 Office: 360.816.3718 | Fax: 360.816.3297
------------------------------------------



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