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Re: Intermedia (ICIX) brokenness...
From: Steve Schaefer <schaefer () simone dashbit com>
Date: Fri, 4 May 2001 14:41:39 -0700 (PDT)


The problem is almost certainly between AS2548 (Digex/Intermedia/icix) and
AS1 (Genuity/bbnplanet).  But I think the reason that the Intermedia hop
times look like Swiss cheese in the return trace is tricky.

My guess is that Intermedia and Genuity have two physical paths between
their networks in Dallas, and that Intermedia is splitting traffic to AS1
between the two paths based on a combination of source and destination IP
address.  One of the paths is overloaded going from AS2548 to AS1 -- the
other is not.

In the forward direction, where the outgoing trace packets going from
AS2548 to AS1 all have the same source and destination addresses, there is
a clean transition.  In the reverse direction, where the source address of
the ICMP error message changes with every hop, the round trip time may be
very short or very long, depending on the router involved.  (Check out hop
11 in the return trace.)

-steve


Dashbit -- The Leader In Internet Topology
www.dashbit.com          www.traceloop.com

**************************************************************************
Here are the traces with AS transitions called out:


 4 gw-swbell.digex.net (206.181.161.153)               8 ms     9 ms   10 ms
 5 aus1-core3-pos1-0.atlas.icix.net (165.117.68.210)   9 ms     6 ms    7 ms
 6 dfw3-core2-pos2-2.atlas.icix.net (165.117.68.218)   18 ms   15 ms   14 ms
 7 dfw3-core1-pos7-0.atlas.icix.net (165.117.48.121)   28 ms   14 ms   14 ms

AS2548 to AS1

 8 a3-0-14.crtntx1-cr12.bbnplanet.net (4.24.147.53)  1366 ms 1336 ms 1360 ms
 9 p6-0.crtntx1-br2.bbnplanet.net (4.24.9.253)       1404 ms 1352 ms 1381 ms
10 p15-0.crtntx1-br1.bbnplanet.net (4.24.10.113)     1374 ms 1327 ms 1359 ms
11 p2-0.crtntx1-cr1.bbnplanet.net (4.24.5.2)         1368 ms 1392 ms 1364 ms
12 p3-0-0.aperian3.bbnplanet.net (4.24.104.98)       1423 ms 1328 ms 1369 ms
13 morannon.the-infinite.org (216.139.208.190)       1423 ms 1383 ms 1374 ms
$


... and the reverse ...


 4 183.at-2-0-0.XR1.DFW7.ALTER.NET (152.63.96.241)     28 ms   28 ms   28 ms
 5 191.ATM10-0-0.BR1.DFW7.ALTER.NET (146.188.241.177)  29 ms   30 ms   21 ms

AS701 to AS2548 -- Hop 6 is a UUNET address on an Intermedia router)

 6 137.39.52.34 (137.39.52.34)                         29 ms   28 ms   28 ms
 7 dfw3-core1-pos6-0.atlas.icix.net (165.117.48.133) 1370 ms 1377 ms 1369 ms
 8 dfw3-core2-pos6-0.atlas.icix.net (165.117.48.122) 1306 ms 1357 ms 1353 ms
 9 aus1-core3-pos3-0.atlas.icix.net (165.117.68.217)   36 ms   36 ms   36 ms
10 aus1-core1-pos9-0-0.atlas.icix.net (165.117.68.209) 37 ms   37 ms   37 ms

AS2548 to AS7293 -- Hop 11 is Intermedia addresses on (a) SW Bell router(s)

11 206.181.161.30 (206.181.161.30)                     37 ms   38 ms
   austin-gw.swbell.com (206.181.161.154)                            1363 ms
12 ded1-fa1-0-0.austtx.swbell.net (151.164.20.243)     38 ms   38 ms   37 ms
13 seton-medical-center-638746.cust-rtr.swbell.net
                                     (151.164.22.46)   34 ms   34 ms   34 ms





















On Fri, 4 May 2001, Dominic J. Eidson wrote:



So who replaced Intermedia's routers with a lump of cheese? :

 4  gw-swbell.digex.net (206.181.161.153)  8 ms  9 ms  10 ms
 5  aus1-core3-pos1-0.atlas.icix.net (165.117.68.210)  9 ms  6 ms  7 ms
 6  dfw3-core2-pos2-2.atlas.icix.net (165.117.68.218)  18 ms  15 ms  14 ms
 7  dfw3-core1-pos7-0.atlas.icix.net (165.117.48.121)  28 ms  14 ms  14 ms
 8  a3-0-14.crtntx1-cr12.bbnplanet.net (4.24.147.53)  1366 ms  1336 ms 1360 ms
 9  p6-0.crtntx1-br2.bbnplanet.net (4.24.9.253)  1404 ms  1352 ms  1381 ms
10  p15-0.crtntx1-br1.bbnplanet.net (4.24.10.113)  1374 ms  1327 ms  1359 ms
11  p2-0.crtntx1-cr1.bbnplanet.net (4.24.5.2)  1368 ms  1392 ms  1364 ms
12  p3-0-0.aperian3.bbnplanet.net (4.24.104.98)  1423 ms  1328 ms  1369 ms
13  morannon.the-infinite.org (216.139.208.190)  1423 ms  1383 ms  1374 ms
$

... and the reverse ...

 4  183.at-2-0-0.XR1.DFW7.ALTER.NET (152.63.96.241)  28 ms  28 ms  28 ms
 5  191.ATM10-0-0.BR1.DFW7.ALTER.NET (146.188.241.177)  29 ms  30 ms  21 ms
 6  137.39.52.34 (137.39.52.34)  29 ms  28 ms  28 ms
 7  dfw3-core1-pos6-0.atlas.icix.net (165.117.48.133)  1370 ms  1377 ms 1369 ms
 8  dfw3-core2-pos6-0.atlas.icix.net (165.117.48.122)  1306 ms  1357 ms 1353 ms
 9  aus1-core3-pos3-0.atlas.icix.net (165.117.68.217)  36 ms  36 ms  36 ms
10  aus1-core1-pos9-0-0.atlas.icix.net (165.117.68.209)  37 ms  37 ms  37 ms
11  206.181.161.30 (206.181.161.30)  37 ms  38 ms austin-gw.swbell.com (206.181.161.154)  1363 ms
12  ded1-fa1-0-0.austtx.swbell.net (151.164.20.243)  38 ms  38 ms  37 ms
13  seton-medical-center-638746.cust-rtr.swbell.net (151.164.22.46)  34 ms 34 ms  34 ms
$







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