nanog mailing list archives

Re: more-specifics in class B space?


From: Jeremy Porter <jerry () fc net>
Date: Fri, 24 Mar 2000 19:23:28 -0600



Looks like they have a routing registry to me:
whois -h rr.level3.net 63.211.112.0

% RIPEdb(3.0.0a13) with ISI RPSL extensions

route:         63.211.112.0/24
descr:         /24 for Wayport POP
origin:        AS14654
mnt-by:        WAYPORT-MNT
changed:       noc () wayport net 20000322
source:        LEVEL3

Why the bogus route, I don't know.

Although this is pretty good:
whois -h rr.level3.net 63.0.0.0

% RIPEdb(3.0.0a13) with ISI RPSL extensions

route:         63.0.0.0/13
descr:         UUNET, An MCI Worldcom Company
               3060 Williams Drive
               Fairfax
               VA 22031 USA
origin:        AS701
mnt-by:        MAINT-AS701
changed:       juzer () UU NET 19981110
source:        RADB



In message <Pine.BSF.4.20.0003241745280.511-100000 () alive znep com>, Marc Slemko
 writes:

Cute.  So, further to this, I noticed that AS3356 (level3.net) was
advertising a route for 63/8, on and off.  Doesn't seem to be advertised
right now, but it comes and goes.  Example history entry from a couple of
minutes ago:

BGP routing table entry for 63.0.0.0/8, version 5217053
Paths: (14 available, no best path)
 Not advertised to any peer
 10764 5646 1239 3356 3356 3356 (history entry)
   206.220.240.223 from 206.220.240.223 (206.220.240.223)
     Origin IGP, localpref 100, external
     Dampinfo: penalty 464, flapped 1 times in 00:17:10
 5056 3561 3356 (history entry)
   167.142.3.6 from 167.142.3.6 (167.142.3.6)
     Origin IGP, localpref 100, external
     Dampinfo: penalty 467, flapped 1 times in 00:17:00
 267 1225 1325 1673 701 3356 (history entry)
   204.42.253.253 from 204.42.253.253 (204.42.253.253)
     Origin IGP, localpref 100, external
     Community: 267:1225 1225:80 1225:1325
     Dampinfo: penalty 732, flapped 2 times in 00:17:08
 1755 1800 1239 3356 3356 3356 (history entry)
   192.121.154.25 from 192.121.154.25 (192.121.154.25)
     Origin IGP, localpref 100, external
     Dampinfo: penalty 469, flapped 1 times in 00:16:50
 293 1800 1239 3356 3356 3356 (history entry)
   134.55.24.6 from 134.55.24.6 (134.55.20.229)
     Origin IGP, localpref 100, external
     Dampinfo: penalty 458, flapped 1 times in 00:17:24
 1849 702 701 3356 (history entry)
[...]

Why are they doing this?  Who knows, they don't respond to email.  But I
notice that they are advertising a whole bunch of /24s, /23s, and other
sub /20 blocks under 63/8.  What a great solution; "hey, people can't
reach us because we are advertising bogusly small blocks, so lets just
advertise an aggregate for the whole /8 to make sure everyone listens to
it".  Riiiiiiiiight.

The concept (ie. advertise an aggregate, even if it doesn't go to exactly
the right place, then also advertise more specifics; if someone filters
the more specifics, the aggregate will serve to get traffic to a network
that does listen to the more specifics) does often work as long as your
network topography is simple enough, it sure doesn't cut down on route
bloat.

Insert standard rant about having a clue before advertising routes, not
advertising bogusly small blocks, routing registries, etc.



--- jerry () fc net
Director Network Operations/Network Engineering, Wayport, Inc.
512-519-6193 www.wayport.net
8303 Mopac Expressway Suite A300, Austin Tx.



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