North American Network Operators Group

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Re: Wierd Route

  • From: Jon Stanley
  • Date: Mon Jan 22 03:47:28 2001

not particularly when you take a look at it.  Misbehaved origin AS:

BGP routing table entry for 63.237.115.192/27, version 3368964
Paths: (3 available, best #3)
  Not advertised to any peer
  5056 3561 3908
    167.142.3.6 from 167.142.3.6 (167.142.3.6)
      Origin IGP, localpref 100, valid, external
  1221 3561 3908
    203.62.248.4 from 203.62.248.4 (203.62.248.4)
      Origin IGP, localpref 100, valid, external
  1221 3561 3908
    203.62.252.21 from 203.62.252.21 (203.62.252.21)
      Origin IGP, localpref 100, valid, external, best
route-views.oregon-ix.net>

A router will take the most specific path that it knows about to a
particular destination.  Since parts of the Internet are seeing a /27
here, it's winding up going all over the place.  It would appear that
AS3561 is allowing such small advertisements from AS3908, and then
providers that dont have filtering at the border based on prefix length
get injected this very specific route.  Yet more examples of what happens
with a lack of filtering........

On Mon, 22 Jan 2001, Joe Budion wrote:

> 
> This one takes the cake for weirdest route I've ever seen:
> 
> #3 sl-gw5-kc-5-0-0.sprintlink.net (144.232.132.45): TTL Exceeded, ttl=253,
> 41 ms
> #4 sl-bb20-kc-0-0.sprintlink.net (144.232.23.1): TTL Exceeded, ttl=252, 40
> ms
> #5 sl-bb20-fw-13-0.sprintlink.net (144.232.9.254): TTL Exceeded, ttl=251, 50
> ms
> #6 Unavailable (144.232.18.162): TTL Exceeded, ttl=250, 50 ms
> #7 dal-core-02.inet.qwest.net (205.171.25.49): TTL Exceeded, ttl=249, 50 ms
> #8 hou-core-01.inet.qwest.net (205.171.5.169): TTL Exceeded, ttl=248, 50 ms
> #9 hou-edge-07.inet.qwest.net (205.171.23.14): TTL Exceeded, ttl=247, 50 ms
> #10 a6-0-6.crtntx1-ba2.bbnplanet.net (4.24.147.21): TTL Exceeded, ttl=241,
> 80 ms
> #11 p10-0.crtntx1-br2.bbnplanet.net (4.24.10.189): TTL Exceeded, ttl=242, 81
> ms
> #12 p2-0.crtntx1-cr8.bbnplanet.net (4.24.8.198): TTL Exceeded, ttl=241, 80
> ms
> #13 p5-0.toucham.bbnplanet.net (4.24.117.66): TTL Exceeded, ttl=240, 100 ms
> #14 den-edge-18.inet.qwest.net (205.171.16.34): TTL Exceeded, ttl=239, 101
> ms
> #15 Unavailable (63.145.64.62): TTL Exceeded, ttl=238, 150 ms
> #16 SLCNTWEB01 (63.237.115.200): Echo Reply, ttl=110, 150 ms
> 
> Statistics: Out 14, in 14, loss 0%, times (min/avg/max) 40/76/150 ms
> 
> joe
> 
>