[j-nsp] Bizaare bug of the year award

[Richard Halfpenny]

Dave Diller wrote:
>
>
>> 6  Wimax-Cali-190-0-0-42.orbitel.net.co (62.154.16.234)  13.428 ms
>>    Wimax-Cali-190-0-0-46.orbitel.net.co (62.154.16.238)  15.618 ms
>>    Wimax-Cali-190-0-0-42.orbitel.net.co (62.154.16.234)  15.574 ms
>>
>> Only thing in common here is the 62 first octet, though you can now see
>> that its zeroing out the top 2 bits when doing its lookup. No clue if
>> there are any other patterns of IPs where this happens also, if all of
>> 62.0.0.0/8 is broken, etc, but its definitely been confirmed on many
>> routers.
>
> Also, 62 + 128 = 190, so that looks like another instance of 
> misparsing the top bit.
>
> -dd


Funny you should mention it.. I noticed this oddness the other week on a 
recently deployed J2350 running 9.2R1.10 and initially thought one of 
our resolving servers had been poisoned!  Here's a trace  to 
www.telekom.de :

rich.halfpenny at j2350-5> traceroute www.telekom.de
traceroute to www.telekom.de (217.6.10.34), 30 hops max, 40 byte packets
 1  m7i-4.u3.tcw.uk.l3.ipv4.exa.net.uk (82.219.1.84)  1.221 ms  1.711 
ms  1.954 ms
 2  195.50.119.149 (195.50.119.149)  85.754 ms  199.598 ms  3.916 ms
 3  ae-11-11.car1.Manchesteruk1.Level3.net (4.69.133.97)  1.854 ms  
3.330 ms  1.127 ms
 4  ae-4-4.ebr1.London1.Level3.net (4.69.133.102)  17.921 ms  15.802 ms  
17.996 ms
 5  ae-12-55.car2.London1.Level3.net (4.68.116.144)  9.687 ms  9.642 ms  
11.618 ms
 6  Wimax-Cali-190-0-0-49.orbitel.net.co (62.156.138.241)  21.040 ms  
9.745 ms  8.808 ms
 7  Wimax-Cali-190-0-0-46.orbitel.net.co (62.154.16.238)  23.500 ms  
22.561 ms  21.999 ms
 8  80.148.103.100 (80.148.103.100)  22.177 ms  22.179 ms  22.268 ms
^C

No in-addr.arpa record for 62.156.138.241 but 62.154.16.238 resolves to  
f-eb1.F.DE.net.DTAG.DE

And to www.zen.co.uk  :

rich.halfpenny at j2350-5> traceroute www.zen.co.uk
traceroute to zen.co.uk (82.71.140.243), 30 hops max, 40 byte packets
 1  193.189.130.10 (193.189.130.10)  3.592 ms  1.787 ms  1.763 ms
 2  Wimax-Cali-190-0-0-36.orbitel.net.co (62.3.83.100)  1.654 ms  1.849 
ms  2.039 ms
 3  fw1.tc.net.hosting.zen.co.uk (82.71.206.251)  1.921 ms  1.933 ms  
1.864 ms
 4  *^C


Rich.

-- 
Network Operations
Exa Networks Ltd :: AS30740
richard.halfpenny at exa-networks.co.uk