Re: Advertising local host routes in BGP?

Carlos,

How do you have a static /32 pointed to the segment if you are the next hop?

R1#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R1(config)#ip route 1.1.1.5 255.255.255.255 1.1.1.1
%Invalid next hop address (it's this router)
R1(config)#R1#conf t

On Fri, Apr 16, 2010 at 5:10 PM, Carlos G Mendioroz <tron_at_huapi.ba.ar> wrote:
> Interesting reading (the loop problem).
> Caused by a floating static route to a multipoint if.
>
> You say:
>> The link says the solution is to point the statics to the next hop;
>> which I can't, as they are local.
> which triggered me to try it. And it works.
>
> You can have a static /32 route to a next hop which is in a connected
> segment. Which solves your need for a given /32 prefix to be published
> by BGP w/o the burden of proxy ARP poisoning your CEF adjacency table...
>
> -Carlos
>
>
>
> Jeffrey Pazahanick @ 16/04/2010 0:37 -0300 dixit:
>> I have a situation where I'm trying to advertise only 4 host routes
>> from a /24 network to my BGP neighbors.
>> As an example,
>>
>> #R1
>> interface g0/0
>> ip addr 1.1.1.2 255.255.255.0
>> standby ip 1.1.1.1
>>
>> router bgp 1
>> network 1.1.1.4 mask 255.255.255.255
>> network 1.1.1.5 mask 255.255.255.255
>> network 1.1.1.7 mask 255.255.255.255
>> network 1.1.1.9 mask 255.255.255.255
>>
>> With a single router, a static route to the interface worked fine..
>>
>> ip route 1.1.1.4 255.255.255.255 g0/0
>> ip route 1.1.1.5 255.255.255.255 g0/0
>> ip route 1.1.1.7 255.255.255.255 g0/0
>> ip route 1.1.1.9 255.255.255.255 g0/0
>>
>> When adding a redundant router, things initially work as well..
>>
>> #R2
>> interface g0/0
>> ip addr 1.1.1.3 255.255.255.0
>> standby ip 1.1.1.1
>>
>> router bgp 1
>> network 1.1.1.4 mask 255.255.255.255
>> network 1.1.1.5 mask 255.255.255.255
>> network 1.1.1.7 mask 255.255.255.255
>> network 1.1.1.9 mask 255.255.255.255
>>
>> ip route 1.1.1.4 255.255.255.255 g0/0
>> ip route 1.1.1.5 255.255.255.255 g0/0
>> ip route 1.1.1.7 255.255.255.255 g0/0
>> ip route 1.1.1.9 255.255.255.255 g0/0
>>
>> The issue arises when R1 fails, R2 has a CEF routing loop..
>>
>> Troubleshooting Cisco Express Forwarding Routing Loops
>> Document ID: 26083
>> http://www.cisco.com/en/US/partner/tech/tk827/tk831/technologies_tech_note09186a00800cdf2e.shtml
>>
>> The link says the solution is to point the statics to the next hop;
>> which I can't, as they are local.
>>
>> Is there another way to advertise these host routes?
>>
>> I've been trying to use inject-maps, but my own routers are the route
>> source, and it doesn't appear to work.
>>
>> Ideas?
>>
>>
>> Blogs and organic groups at http://www.ccie.net
>>
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>>
>>
>>
>>
>>
>>
>>
>
> --
> Carlos G Mendioroz <tron_at_huapi.ba.ar> LW7 EQI Argentina

Blogs and organic groups at http://www.ccie.net
Received on Fri Apr 16 2010 - 23:33:56 ART