Re: Advertising local host routes in BGP?

Jeffrey,

Use "bgp inject-map" for this.

ip prefix-list TRACKER seq 10 permit 1.1.1.0/24
!
ip prefix-list INJECTED seq 10 permit 1.1.1.1/32
ip prefix-list INJECTED seq 20 permit 1.1.1.3/32
ip prefix-list INJECTED seq 30 permit 1.1.1.4/32
ip prefix-list INJECTED seq 40 permit 1.1.1.5/32
!
route-map TRACK permit 10
 match ip address prefix-list TRACKER
!
route-map INJECT permit 10
 set ip address prefix-list INJECTED
!
router bgp 1
 bgp inject-map INJECT exist-map TRACK copy-attributes
!

I'm on the airport now, can't really try it out, but this will at
least push you in the right direction.

--
Marko Milivojevic - CCIE #18427
Senior Technical Instructor - IPexpert
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On Wed, Apr 21, 2010 at 03:42, Jeffrey Pazahanick <jeffpaz_at_gmail.com> wrote:
> I appreciate your help so far. B 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, B 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
>>>>> B via 1.1.1.5, 0 dependencies, recursive
>>>>> B  B unresolved
>>>>>
>>>>> R1#sh arp
>>>>> Protocol B Address B  B  B  B  B Age (min) B Hardware Addr B  Type B  Interface
>>>>> Internet B 1.1.1.1 B  B  B  B  B  B  B  B  - B  0015.fa64.6d21 B ARPA
>>>>> FastEthernet0/1
>>>>> Internet B 1.1.1.5 B  B  B  B  B  B  B  B 16 B  0015.fa64.7b13 B ARPA
>>>>> FastEthernet0/1
>>>>> Internet B 10.1.12.1 B  B  B  B  B  B  B  - B  0015.fa64.6d20 B ARPA
>>>>> FastEthernet0/0
>>>>> Internet B 10.1.12.2 B  B  B  B  B  B  B 16 B  0015.fa64.7518 B ARPA
>>>>> FastEthernet0/0
>>>>>
>>>>> R1#sh ip route 1.1.1.5
>>>>> Routing entry for 1.1.1.5/32
>>>>> B Known via "static", distance 1, metric 0
>>>>> B Advertised by bgp 1
>>>>> B Routing Descriptor Blocks:
>>>>> B * 1.1.1.5
>>>>> B  B  B Route metric is 0, traffic share count is 1
>>>>>
>>>>> ----
>>>>>
>>>>> Remove the static.
>>>>>
>>>>> R1#conf t
>>>>> Enter configuration commands, one per line. B 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
>>>>> B via FastEthernet0/1, 0 dependencies
>>>>> B  B valid glean adjacency
>>>>> R1#sh arp
>>>>> Protocol B Address B  B  B  B  B Age (min) B Hardware Addr B  Type B  Interface
>>>>> Internet B 1.1.1.1 B  B  B  B  B  B  B  B  - B  0015.fa64.6d21 B ARPA
>>>>> FastEthernet0/1
>>>>> Internet B 1.1.1.5 B  B  B  B  B  B  B  B 19 B  0015.fa64.7b13 B ARPA
>>>>> FastEthernet0/1
>>>>> Internet B 10.1.12.1 B  B  B  B  B  B  B  - B  0015.fa64.6d20 B ARPA
>>>>> FastEthernet0/0
>>>>> Internet B 10.1.12.2 B  B  B  B  B  B  B 19 B  0015.fa64.7518 B ARPA
>>>>> FastEthernet0/0
>>>>> R1#sh ip route 1.1.1.5
>>>>> Routing entry for 1.1.1.0/24
>>>>> B Known via "connected", distance 0, metric 0 (connected, via interface)
>>>>> B Routing Descriptor Blocks:
>>>>> B * directly connected, via FastEthernet0/1
>>>>> B  B  B 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. B 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 B <tron_at_huapi.ba.ar> B LW7 EQI B Argentina
>>>>>>>>
>>>>>> --
>>>>>> Carlos G Mendioroz B <tron_at_huapi.ba.ar> B LW7 EQI B Argentina
>>>>>>
>>>> --
>>>> Carlos G Mendioroz B <tron_at_huapi.ba.ar> B LW7 EQI B Argentina
>>>
>>>
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>>>
>>> _______________________________________________________________________
>>> Subscription information may be found at:
>>> http://www.groupstudy.com/list/CCIELab.html
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>
>> --
>> Carlos G Mendioroz B <tron_at_huapi.ba.ar> B LW7 EQI B Argentina
>
>
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>
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