[c-nsp] Quick routing question.

[Jon Lewis]

On Thu, 9 Sep 2010, Drew Weaver wrote:

> [root at vmz bin]# tracert x.x.x.13
> traceroute to x.x.x.13 (x.x.x.13), 30 hops max, 40 byte packets
> 1  gw (gw)  0.486 ms  0.458 ms  0.463 ms
> 2  core (core)  0.460 ms  0.710 ms  0.709 ms
> 3  rtr (rtr)  0.427 ms  0.428 ms  0.425 ms
> 4  x.x.x.Level3.net (x.x.x.13)  3.238 ms  3.238 ms  3.236 ms

So you have redistributed the new connection /30 into your IGP.  With BGP 
not turned up, the return path is almost certainly not the reverse of the 
above...so is there some reason x.x.x.Level3.net can't send packets back 
your way via the connected 10gigE?  I assume if you ask a Level3 engineer 
to ping you at x.x.x.14 from x.x.x.Level3.net, it doesn't work?

> rtr#sh ip arp
> Protocol  Address          Age (min)  Hardware Addr   Type        Interface
> Internet  x.x.x.14              -   xxxx.xxxx.a9dc  ARPA        GigabitEthernet2/1/0
> Internet  x.x.x.13             14   xxxx.xxxx.4d7a  ARPA        GigabitEthernet2/1/0
> Internet  x.x.x.12              -   xxxx.xxxx.a9dc  ARPA        GigabitEthernet2/1/0

That rules out my first guess.  Though probably not related, why is there 
an arp entry for .12?

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  Jon Lewis, MCP :)           |  I route
  Senior Network Engineer     |  therefore you are
  Atlantic Net                |
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