Re: Advertising local host routes in BGP?

I appreciate your help so far. My problem is as originally stated..
Is there a way to advertise host routes in BGP from a connected
interface without creating a static route pointing to that interface.

int g0/0
ip addr 1.1.1.1 255.255.255.0

router bgp 1
neig 2.2.2.2 remote-as 2
network 1.1.1.3 mask 255.255.255.255
network 1.1.1.4 mask 255.255.255.255
network 1.1.1.5 mask 255.255.255.255

I want to advertise 1.1.1.3, .4, and 5 in BGP without doing

ip route 1.1.1.3 255.255.255.255 g0/0
ip route 1.1.1.4 255.255.255.255 g0/0
ip route 1.1.1.5 255.255.255.255 g0/0

My output of the FIB and RIB were based on the suggestion of

ip route 1.1.1.3 255.255.255.255 1.1.1.3
ip route 1.1.1.4 255.255.255.255 1.1.1.4
ip route 1.1.1.5 255.255.255.255 1.1.1.5

which didn't work.

On Tue, Apr 20, 2010 at 8:24 PM, Carlos G Mendioroz <tron_at_huapi.ba.ar> wrote:
> You tell me. Again, I don't fully understand what the problem is now.
> I guess you have to reproduce the problem in a lab scenario before you
> try to find a solution...
>
> -Carlos
>
> Jeffrey Pazahanick @ 20/04/2010 19:17 -0300 dixit:
>> I don't have the FIB/RIB data from the actual failure; only from
>> trying to find a way to advertise a host route in my lab..
>> So bgp inject-map is off of the table?
>>
>> On Tue, Apr 20, 2010 at 10:48 AM, Carlos G Mendioroz <tron_at_huapi.ba.ar> wrote:
>>> Hmm, I don't know what the problem is. All the info you send now seems ok.
>>> Can you provide a small configuration set that we can use to reproduce the
>>> issue ?
>>> If this is related to the doc you referred before, your FIB would be
>>> inconsistent with your RIB, which is not the case in the provided
>>> show ooutputs.
>>>
>>> -Carlos
>>>
>>> Jeffrey Pazahanick @ 20/4/2010 11:30 -0300 dixit:
>>>> That doesn't seem to work either...
>>>>
>>>> ip route 1.1.1.5 255.255.255.255 1.1.1.5
>>>>
>>>>
>>>> R1#sh ip cef 1.1.1.5 det
>>>> 1.1.1.5/32, version 37, epoch 0
>>>> 0 packets, 0 bytes
>>>> via 1.1.1.5, 0 dependencies, recursive
>>>> unresolved
>>>>
>>>> R1#sh arp
>>>> Protocol Address Age (min) Hardware Addr Type Interface
>>>> Internet 1.1.1.1 - 0015.fa64.6d21 ARPA
>>>> FastEthernet0/1
>>>> Internet 1.1.1.5 16 0015.fa64.7b13 ARPA
>>>> FastEthernet0/1
>>>> Internet 10.1.12.1 - 0015.fa64.6d20 ARPA
>>>> FastEthernet0/0
>>>> Internet 10.1.12.2 16 0015.fa64.7518 ARPA
>>>> FastEthernet0/0
>>>>
>>>> R1#sh ip route 1.1.1.5
>>>> Routing entry for 1.1.1.5/32
>>>> Known via "static", distance 1, metric 0
>>>> Advertised by bgp 1
>>>> Routing Descriptor Blocks:
>>>> * 1.1.1.5
>>>> Route metric is 0, traffic share count is 1
>>>>
>>>> ----
>>>>
>>>> Remove the static.
>>>>
>>>> R1#conf t
>>>> Enter configuration commands, one per line. End with CNTL/Z.
>>>> R1(config)#no ip route 1.1.1.5 255.255.255.255 1.1.1.5
>>>> R1(config)#^Z
>>>> R1#ping
>>>> *Apr 20 14:29:07.057: %SYS-5-CONFIG_I: Configured from console by console
>>>> R1#ping 1.1.1.5
>>>>
>>>> Type escape sequence to abort.
>>>> Sending 5, 100-byte ICMP Echos to 1.1.1.5, timeout is 2 seconds:
>>>> !!!!!
>>>> Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/4 ms
>>>> R1#sh ip cef 1.1.1.5 det
>>>> 1.1.1.0/24, version 32, epoch 0, attached, connected
>>>> 0 packets, 0 bytes
>>>> via FastEthernet0/1, 0 dependencies
>>>> valid glean adjacency
>>>> R1#sh arp
>>>> Protocol Address Age (min) Hardware Addr Type Interface
>>>> Internet 1.1.1.1 - 0015.fa64.6d21 ARPA
>>>> FastEthernet0/1
>>>> Internet 1.1.1.5 19 0015.fa64.7b13 ARPA
>>>> FastEthernet0/1
>>>> Internet 10.1.12.1 - 0015.fa64.6d20 ARPA
>>>> FastEthernet0/0
>>>> Internet 10.1.12.2 19 0015.fa64.7518 ARPA
>>>> FastEthernet0/0
>>>> R1#sh ip route 1.1.1.5
>>>> Routing entry for 1.1.1.0/24
>>>> Known via "connected", distance 0, metric 0 (connected, via interface)
>>>> Routing Descriptor Blocks:
>>>> * directly connected, via FastEthernet0/1
>>>> Route metric is 0, traffic share count is 1
>>>>
>>>>
>>>> Any other suggestions?
>>>>
>>>> On Sat, Apr 17, 2010 at 6:57 AM, Carlos G Mendioroz <tron_at_huapi.ba.ar>
>>>> wrote:
>>>>> Send it to the destination:
>>>>>
>>>>> ip route 1.1.1.5 255.255.255.255 1.1.1.5
>>>>>
>>>>> That worked in a couple of versions I tested it. I did no other test,
>>>>> so I don't know if it fixes your issue, but it may help.
>>>>>
>>>>> -Carlos
>>>>>
>>>>>
>>>>> Jeffrey Pazahanick @ 17/04/2010 1:33 -0300 dixit:
>>>>>> 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
>>>>>>>>
>>>>>>>>
>>>>>>>> _______________________________________________________________________
>>>>>>>> Subscription information may be found at:
>>>>>>>> http://www.groupstudy.com/list/CCIELab.html
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>> --
>>>>>>> Carlos G Mendioroz <tron_at_huapi.ba.ar> LW7 EQI Argentina
>>>>>>>
>>>>> --
>>>>> Carlos G Mendioroz <tron_at_huapi.ba.ar> LW7 EQI Argentina
>>>>>
>>> --
>>> Carlos G Mendioroz <tron_at_huapi.ba.ar> LW7 EQI Argentina
>>
>>
>> Blogs and organic groups at http://www.ccie.net
>>
>> _______________________________________________________________________
>> Subscription information may be found at:
>> http://www.groupstudy.com/list/CCIELab.html
>>
>>
>>
>>
>>
>>
>>
>
> --
> Carlos G Mendioroz <tron_at_huapi.ba.ar> LW7 EQI Argentina

Blogs and organic groups at http://www.ccie.net
Received on Tue Apr 20 2010 - 20:42:02 ART