Routing Suggestions

Thu Jan 13 00:58:25 UTC 2011

On Thu, 13 Jan 2011, Adrian Chadd wrote:

> On Wed, Jan 12, 2011, Jon Lewis wrote:
>> On Wed, 12 Jan 2011, Jared Mauch wrote:
>>
>>> I suggest using one of the reserved/private BGP asns for this purpose.
>>>
>>> ASNumber:       64512 - 65535
>>
>> It sounds to me like Company B isn't doing BGP (probably has no experience
>> with it) and if there's only a single prefix per side of the cross
>> connect, especially if the cross connect is going into routers smart
>> enough to remove a route from the table if the destination interface is
>> down, static would do just fine.
>
> Unless you'd like to ensure the sensitive traffic doesn't cross an
> "unsafer" default rout path if the XC is down.

BGP would have that same issue since B is default routing to their 
provider.

[config for B]
ip route <A's prefix> <mask> <gw to A>
ip route <A's prefix> <mask> null0 250
ip route 0.0.0.0 0.0.0.0 <B's provider>

problem solved.  If the gw to A is reachable, traffic goes via the cross 
connect.  If the gw is down, traffic goes nowhere.

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