Re: Advertising local host routes in BGP?

Interesting timing...
I was able to test last night on the ASR1k.

The ping worked, but the host route was not in the routing table (thus
not advertised).

ASR-ROUTER1(config)#ip route 65.255.80.7 255.255.255.255 65.255.80.7

ASR-ROUTER1#ping 65.255.80.7

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 65.255.80.7, timeout is 2 seconds:
!!!!!

ASR-ROUTER1#sh ip route 65.255.80.7
Routing entry for 65.255.80.0/26
  Known via "connected", distance 0, metric 0 (connected, via interface)
  Redistributing via ospf 100
  Routing Descriptor Blocks:
  * directly connected, via GigabitEthernet0/0/1
      Route metric is 0, traffic share count is 1

I suppose I really need to take another outage; fail the ASR1 and see
if the behavior returns, and if it does, dig deeper into the root
cause..
That CEF loop doc certainly does feel like the issue though..

On Fri, May 14, 2010 at 7:05 AM, Carlos G Mendioroz <tron_at_huapi.ba.ar> wrote:
> FTR, I was *not* able to reproduce the problem using statics to interface.
> I think that the referred CEF problem needs a *default* route to
> interface to be triggered.
> You may be hunting in the wrong cave :)
> -Carlos
>
> Jeffrey Pazahanick @ 6/05/2010 17:53 -0300 dixit:
>> That is very interesting...
>>
>> Anyone have an ASR1k running 2.5.2 laying around to test? :)
>>
>> On Thu, May 6, 2010 at 3:39 PM, Carlos G Mendioroz <tron_at_huapi.ba.ar> wrote:
>>> Using a 2811:
>>>
>>> PSTN1(config)#int f 0/0
>>> PSTN1(config-if)#ip add 192.168.1.241 255.255.0.0
>>> PSTN1(config-if)#no shut
>>> PSTN1(config-if)#
>>> *May 6 20:47:20.373: %LINK-3-UPDOWN: Interface FastEthernet0/0, changed
>>> state to up
>>> *May 6 20:47:21.373: %LINEPROTO-5-UPDOWN: Line protocol on Interface
>>> FastEthernet0/0, changed state to up
>>> PSTN1(config-if)#end
>>> PSTN1#
>>> *May 6 20:47:26.533: %SYS-5-CONFIG_I: Configured from console by console
>>> PSTN1#
>>> PSTN1#ping 192.168.0.1
>>>
>>> Type escape sequence to abort.
>>> Sending 5, 100-byte ICMP Echos to 192.168.0.1, timeout is 2 seconds:
>>> .!!!!
>>> Success rate is 80 percent (4/5), round-trip min/avg/max = 1/1/4 ms
>>> PSTN1#conf t
>>> Enter configuration commands, one per line. End with CNTL/Z.
>>> PSTN1(config)#ip route 192.168.0.1 255.255.255.255 192.168.0.1
>>> PSTN1(config)#end
>>> PSTN1#ping 192.168.0.1
>>> *May 6 20:48:19.337: %SYS-5-CONFIG_I: Configured from coconf t
>>> PSTN1#ping 192.168.0.1
>>>
>>> Type escape sequence to abort.
>>> Sending 5, 100-byte ICMP Echos to 192.168.0.1, timeout is 2 seconds:
>>> !!!!!
>>> Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/4 ms
>>> PSTN1#sh ip route
>>> Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
>>> D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
>>> N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
>>> E1 - OSPF external type 1, E2 - OSPF external type 2
>>> i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
>>> ia - IS-IS inter area, * - candidate default, U - per-user static
>>> route
>>> o - ODR, P - periodic downloaded static route
>>>
>>> Gateway of last resort is not set
>>>
>>> 192.168.0.0/32 is subnetted, 1 subnets
>>> S 192.168.0.1 [1/0] via 192.168.0.1
>>> C 192.168.0.0/16 is directly connected, FastEthernet0/0
>>>
>>> PSTN1#sh ip cef 192.168.0.1
>>> 192.168.0.1/32, version 10, epoch 0
>>> 0 packets, 0 bytes
>>> via 192.168.0.1, 0 dependencies, recursive
>>> unresolved
>>> PSTN1#ping 192.168.0.1
>>>
>>> Type escape sequence to abort.
>>> Sending 5, 100-byte ICMP Echos to 192.168.0.1, timeout is 2 seconds:
>>> !!!!!
>>> Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/4 ms
>>> PSTN1#sh ver
>>> Cisco IOS Software, 2800 Software (C2800NM-ADVENTERPRISEK9_IVS-M), Version
>>> 12.4(9)T7, RELEASE SOFTWARE (fc3)
>>> Technical Support: http://www.cisco.com/techsupport
>>> Copyright (c) 1986-2008 by Cisco Systems, Inc.
>>> Compiled Thu 10-Jan-08 16:36 by prod_rel_team
>>> ...
>>>
>>>
>>> So it seems it's either architecture or IOS version dependent.
>>>
>>>
>>> Jeffrey Pazahanick @ 6/5/2010 12:14 -0300 dixit:
>>>> Carlos,
>>>> What platform did you test a static route pointing to a host on a
>>>> locally connected network?
>>>> I'm labbing this on 1841s add get the following:
>>>>
>>>> R1(config)#do 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(config)#ip route 1.1.1.5 255.255.255.255 1.1.1.5
>>>> R1(config)#do ping 1.1.1.5
>>>> *May 6 15:14:52.925: RT: network 1.0.0.0 is now variably masked
>>>> *May 6 15:14:52.925: RT: add 1.1.1.5/32 via 1.1.1.5, static metric [1/0]
>>>> *May 6 15:14:52.925: RT: NET-RED 1.1.1.5/32
>>>> *May 6 15:14:53.021: RT: recursion error routing 1.1.1.5 - probable
>>>> routing loop
>>>> R1(config)#do 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:
>>>>
>>>> *May 6 15:14:54.677: RT: recursion error routing 1.1.1.5 - probable
>>>> routing loop
>>>> *May 6 15:14:54.677: RT: recursion error routing 1.1.1.5 - probable
>>>> routing loop.
>>>> *May 6 15:14:56.677: RT: recursion error routing 1.1.1.5 - probable
>>>> routing loop
>>>> *May 6 15:14:56.677: RT: recursion error routing 1.1.1.5 - probable
>>>> routing loop
>>>> *May 6 15:14:56.677: RT: recursion error routing 1.1.1.5 - probable
>>>> routing loop.
>>>> *May 6 15:14:58.677: RT: recursion error routing 1.1.1.5 - probable
>>>> routing loop
>>>> *May 6 15:14:58.677: RT: recursion error routing 1.1.1.5 - probable
>>>> routing loop
>>>> *May 6 15:14:58.677: RT: recursion error routing 1.1.1.5 - probable
>>>> routing loop.
>>>> *May 6 15:15:00.677: RT: recursion error routing 1.1.1.5 - probable
>>>> routing loop
>>>> *May 6 15:15:00.677: RT: recursion error routing 1.1.1.5 - probable
>>>> routing loop
>>>> *May 6 15:15:00.677: RT: recursion error routing 1.1.1.5 - probable
>>>> routing loop.
>>>> *May 6 15:15:02.677: RT: recursion error routing 1.1.1.5 - probable
>>>> routing loop
>>>> *May 6 15:15:02.677: RT: recursion error routing 1.1.1.5 - probable
>>>> routing loop
>>>> *May 6 15:15:02.677: RT: recursion error routing 1.1.1.5 - probable
>>>> routing loop.
>>>> Success rate is 0 percent (0/5)
>>>>
>>>>
>>>> On Mon, Apr 26, 2010 at 3:32 PM, Carlos G Mendioroz <tron_at_huapi.ba.ar>
>>>> wrote:
>>>>> Have you been able to reproduce the issue in a lab environment ?
>>>>> Because the statics pointing to the next hop should take care of the CEF
>>>>> problem if I understood it...
>>>>>
>>>>> -Carlos
>>>>>
>>>>> Jeffrey Pazahanick @ 26/04/2010 17:28 -0300 dixit:
>>>>>> The topology is like this:
>>>>>>
>>>>>> upstream peer upstream peer
>>>>>> | |
>>>>>> -------------------------------------------
>>>>>> | |
>>>>>> R1 (1.1.1.2) R2 (1.1.1.3)
>>>>>> | g0/0 | g0/0
>>>>>> -------------------------------------------
>>>>>> |
>>>>>> host (1.1.1.5)
>>>>>>
>>>>>> The issue I had was related to the CEF issue I mentioned when using
>>>>>> static routes pointing to an interface, so I need find a different way
>>>>>> of advertising host routes into BGP from a local network.
>>>>>>
>>>>>>
>>>>>> On Thu, Apr 22, 2010 at 7:20 AM, Carlos G Mendioroz <tron_at_huapi.ba.ar>
>>>>>> wrote:
>>>>>>> Would you please repost your original topology and perceived problem ?
>>>>>>> I got carried away because of your reference to the CEF issue, but
>>>>>>> you have provided not enough info to actually reproduce your situation.
>>>>>>>
>>>>>>> -Carlos
>>>>> --
>>>>> 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 Fri May 14 2010 - 09:17:55 ART