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Re: Next_Hop stuff in prtraceroute

  • To: Erik-Jan Bos < >
  • From: Marten Terpstra < >
  • Date: Fri, 14 Jan 1994 17:17:01 +0100

Erik-Jan Bos <erik-jan.bos@localhost writes
 * Tony,
 * 
 * here I am again about the next hop stuff... Look at this:
 * 
 * survis bos % prtraceroute ns.eu.net
 * traceroute to ns.eu.net (192.16.202.11) with AS and policy additions
 * 
 *  1 AS1103  surrogate.surfnet.nl           192.87.108.1       [I]
 *  2 AS1103  Utrecht1.router.surfnet.nl     145.41.49.161      [I]
 *  3 AS1103  Amsterdam1.router.surfnet.nl   145.41.1.193       [I]
 *  4 AS 286  Amsterdam.NL.EU.net            192.87.4.20        [?NH 1128]
 *  5 AS 286  ns.EU.net                      192.16.202.11      [I]
 * 
 * AS Path followed:  1103 [?1128?] 286
 * 
 * AS1103 = SURFnet IP
 * AS1128 = EuropaNET PoP Amsterdam
 * AS 286 = EUnet-central AS
 * 
 * At a first glance this look okay, the SURFnet box gets the next hop from
 * the EuropaNET box (living is AS1128).
 * 
 * But, there is no peering between AS1128 and AS286 at the moment. The
 * box in AS1128 gets the next hop from AS1755. This means it can be a
 * "recursive" process (not the correct name for it but what I mean is
 * that you cannot stop at 1 iteration).
 * 
 * Shouldn't line 4 of the above output be like this:
 * 
 *  4 AS 286  Amsterdam.NL.EU.net            192.87.4.20        [?NH 1128 1755]

I understand what you are aiming at, you get a next hop from someone
who gets a next hop.  This is difficult. The next hop provider we
guess now is easy, since we do not have to get and parse any special
information. The extra step you wish IS difficult, because then we
need to go and get the information where AS1128 would get AS286 ...
I'll have a look over the weekend, but I do not think this is very
easy.

The prtraceroute is still right though, you do get your next hop from
1128, you now only want to find out where 1128 gets its 286 info from.
(and so on until you find someone who gets it directly from 286)

-Marten



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