[rbak-nsp] strange BGP printouts...
Marcin Kuczera
marcin at leon.pl
Mon Jan 16 09:04:02 EST 2012
Tomas Lynch wrote:
> Marcin,
>
> Actually the strange thing here is that for the second peer the
> adevetised routes are showing your ASN in the path; this shouldn't be
> happen at all. Do you have anywhere the "accept own as " command?
> (don't remember the exact name of the command but you get the idea)
>
> I think you have some kind of loop somewhere. Can you provide the
> "show bgp route 31.11.128.0/17" output please?
Look, this is not "received" but "advertised".
In advertised it makes sense - so that I see what the other side will see.
Prevention of loops is a feature of BGP protocol itself, maybe can be
ommited with command, but I don't do it.
Here is a printout:
[bgp1]R0_SE600#show bgp route 31.11.128.0/17
BGP ipv4 unicast routing table entry: 31.11.128.0/17, version 20274522
Paths: total 7, best path count 1, best peer 93.105.7.241
Advertised to non-peer-group peers: 7
91.195.159.6 91.195.159.10 91.195.159.30 91.195.159.46 91.195.159.138
91.195.159.230 195.66.73.245
12968 29314 29314 29314
Nexthop 93.159.57.141 (0), peer 93.159.57.141 (93.159.57.8), AS 12968
Origin IGP, localpref 499, med 0, weight 100, external
Community: 13000:9001
15744 13293 1299 3356 29314
Nexthop 212.106.159.142 (0), peer 212.106.159.142 (83.230.95.254), AS
15744
Origin IGP, localpref 200, med 0, weight 100, external
Community: 13000:9001
24724 29314
Nexthop 193.111.38.97 (0), peer 193.111.38.97 (193.111.37.1), AS 24724
Origin IGP, localpref 200, med 0, weight 100, external
Community: 29314:999
29314
Nexthop 93.105.7.241 (0), peer 93.105.7.241 (172.17.17.251), AS 29314
Origin IGP, localpref 600, med 0, weight 100, external, best
Community: 13000:9998 13000:9999
29314 29314 29314
Nexthop 195.182.218.187 (0), peer 195.182.218.99 (195.182.218.99), AS
8545
Origin IGP, localpref 501, med 0, weight 100, external
Community: 8545:29314 8545:65120 29314:999
29314 29314 29314
Nexthop 195.182.218.187 (0), peer 195.182.218.100 (195.182.218.100),
AS 8545
Origin IGP, localpref 501, med 0, weight 100, external
Community: 8545:29314 8545:65120 29314:999
50607 29314
Nexthop 195.191.171.169 (0), peer 195.191.171.169 (195.191.171.4), AS
50607
Origin IGP, localpref 220, med 0, weight 100, external
Community: 13000:9999
[bgp1]R0_SE600#
Regards,
Marcin
>
> Tomas Lynch
>
> On Sun, Jan 15, 2012 at 9:34 AM, Marcin Kuczera <marcin at leon.pl> wrote:
>> Christopher O'Shea wrote:
>>> Hi Marcin,
>>>
>>> What does router map look like.
>>
>> !
>> route-map direct-peering-rix-in permit 10
>> set community 13000:9998 13000:9999
>> set local-preference 600
>> !
>> route-map direct-peering-rix-out permit 5
>> match as-path-list AS13000-only
>> route-map direct-peering-rix-out permit 10
>> match community-list kdi-full-bgp
>> route-map direct-peering-rix-out permit 11
>> match community-list rix-peering
>> !
>>
>> !
>> community-list kdi-full-bgp
>> seq 10 permit 13000:9900
>> !
>> community-list rix-peering
>> seq 10 permit 13000:9998
>> !
>>
>> !
>> as-path-list AS13000-only
>> seq 10 permit ^$
>> !
>>
>>
>> Regards,
>> Marcin
>>
>>
>>
>>> Chris O'Shea
>>>
>>>
>>>
>>> On Sun, Jan 15, 2012 at 10:24 AM, Marcin Kuczera <marcin at leon.pl
>>> <mailto:marcin at leon.pl>> wrote:
>>>
>>>
>>> ripleyron at gmail.com <mailto:ripleyron at gmail.com> wrote:
>>>
>>> Not really, the originator of the route comes from an igp, this
>>> is pretty much all the time, it' advertised to the world and you
>>> receive it via your external eBGP session, but the initial
>>> origin of the route is preserved in the AS-PATH.
>>>
>>> if you have two eBGP sessions with two different upstream
>>> providers, you'll likely see differences in as-path etc.
>>>
>>>
>>> Ok, prefix is allways sources by some IGP - maybe except quagga
>>> where "network 'prefix'" doesn't require IGP to put this prefix in
>>> routing table ;)
>>>
>>> However look at printouts of advertised routes copied fom below:
>>>
>>> >>>> [bgp1]R0_SE600#show bgp route neighbor 91.195.159.6 advertised
>>> >>>> Address Family: ipv4 unicast
>>> >>>> BGP table version is 24923469, local router ID is 195.66.73.250
>>> >>>> Status codes: d damped, h history, > best, i internal
>>> >>>> Origin codes: i - IGP, e - EGP, ? - incomplete
>>> >>>>
>>> >>>> Network Next Hop Metric LocPrf
>>> Weight Path
>>> >>>>> 31.11.128.0/17 <http://31.11.128.0/17> 91.195.159.5
>>> 0 600 100 i
>>> >>>>> 37.8.192.0/18 <http://37.8.192.0/18> 91.195.159.5
>>> 0 600 100 i
>>>
>>> >>>> [bgp1]R0_SE600#show bgp route neighbor 91.195.159.10 advertised
>>> >>>> Address Family: ipv4 unicast
>>> >>>> BGP table version is 24923504, local router ID is 195.66.73.250
>>> >>>> Status codes: d damped, h history, > best, i internal
>>> >>>> Origin codes: i - IGP, e - EGP, ? - incomplete
>>> >>>>
>>> >>>> Network Next Hop Metric LocPrf
>>> Weight Path
>>> >>>>> 31.11.128.0/17 <http://31.11.128.0/17> 91.195.159.9
>>> 0 600 100 13000 29314 i
>>> >>>>> 37.8.192.0/18 <http://37.8.192.0/18> 91.195.159.9
>>> 0 600 100 13000 29314 i
>>>
>>>
>>> Our AS is 13000.
>>> same routes, learned from same peer (external, AS29314) - advertised
>>> to 2 external peers with IDENTICAL route maps...
>>> First one is not showing AS patch at all....
>>>
>>> This is in my opinion some kind of a bug...
>>>
>>> Regards,
>>> Marcin
>>>
>>>
>>>
>>>
>>>
>>> Ron
>>>
>>> Sent from my BlackBerry device on the Rogers Wireless Network
>>>
>>> -----Original Message-----
>>> From: Marcin Kuczera <marcin at leon.pl <mailto:marcin at leon.pl>>
>>> Date: Sat, 14 Jan 2012 10:55:05 To: Ron
>>> Ripley<ripleyron at gmail.com <mailto:ripleyron at gmail.com>>
>>> Cc: Ronald Voermans<r.voermans at global-__datacenter.nl
>>> <mailto:r.voermans at global-datacenter.nl>>;
>>> redback-nsp at puck.nether.net
>>> <mailto:redback-nsp at puck.nether.net><re__dback-nsp at puck.nether.net
>>> <mailto:redback-nsp at puck.nether.net>>
>>> Subject: Re: [rbak-nsp] strange BGP printouts...
>>>
>>> Ron Ripley wrote:
>>>
>>> Hi,
>>>
>>> The "i" at the end of the AS Path; refers to the origin of
>>> an IGP, not iBGP. Origin codes: i - IGP, e - EGP, ? -
>>> incomplete
>>>
>>>
>>> So still printouts are faulty, because all routes from printout
>>> below are from EGP (external BGP).
>>>
>>> Regards,
>>> Marcin
>>>
>>>
>>> Ron
>>>
>>> On 2012-01-13, at 5:58 AM, Ronald Voermans wrote:
>>>
>>> Hi Marcin,
>>>
>>> the first one is seen as an internal neighbour (ibgp),
>>> hence the 'i' in the path. No as-path is neccessary with
>>> ibgp!
>>>
>>> Regards,
>>> Ronald
>>>
>>> Op 13 jan. 2012, om 13:53 heeft Marcin Kuczera het
>>> volgende geschreven:
>>>
>>> look here, I have 2 peers with exacly the same
>>> route-maps
>>>
>>> Neighbor AS MsgRcvd MsgSent TblVer
>>> InQ OutQ Rst Up/Down PfxRcvd/Sent RstNeeded
>>> 91.195.159.6 30799 91 102 24923197
>>> 0 0 1 01:24:59 4 274 No
>>> 91.195.159.10 196858 18964 18991 24923213
>>> 0 0 2 1w6d 3 272 No
>>>
>>>
>>> Now, look at example of advertised routes:
>>>
>>>
>>> [bgp1]R0_SE600#show bgp route neighbor 91.195.159.6
>>> advertised
>>> Address Family: ipv4 unicast
>>> BGP table version is 24923469, local router ID is
>>> 195.66.73.250
>>> Status codes: d damped, h history, > best, i internal
>>> Origin codes: i - IGP, e - EGP, ? - incomplete
>>>
>>> Network Next Hop Metric
>>> LocPrf Weight Path
>>>
>>> 31.11.128.0/17 <http://31.11.128.0/17>
>>> 91.195.159.5 0 600 100 i
>>> 37.8.192.0/18 <http://37.8.192.0/18>
>>> 91.195.159.5 0 600 100 i
>>> 77.222.224.0/21 <http://77.222.224.0/21>
>>> 91.195.159.5 0 600 100 i
>>> 77.222.232.0/21 <http://77.222.232.0/21>
>>> 91.195.159.5 0 600 100 i
>>> 77.222.240.0/20 <http://77.222.240.0/20>
>>> 91.195.159.5 0 600 100 i
>>> 78.31.136.0/21 <http://78.31.136.0/21>
>>> 91.195.159.5 0 600 100 i
>>> 78.88.0.0/20 <http://78.88.0.0/20>
>>> 91.195.159.5 0 600 100 i
>>> 78.88.16.0/22 <http://78.88.16.0/22>
>>> 91.195.159.5 0 600 100 i
>>> 78.88.20.0/23 <http://78.88.20.0/23>
>>> 91.195.159.5 0 600 100 i
>>> 78.88.22.0/23 <http://78.88.22.0/23>
>>> 91.195.159.5 0 600 100 i
>>> 78.88.24.0/21 <http://78.88.24.0/21>
>>> 91.195.159.5 0 600 100 i
>>> 78.88.32.0/21 <http://78.88.32.0/21>
>>> 91.195.159.5 0 600 100 i
>>> 78.88.40.0/23 <http://78.88.40.0/23>
>>> 91.195.159.5 0 600 100 i
>>> 78.88.43.0/24 <http://78.88.43.0/24>
>>> 91.195.159.5 0 600 100 i
>>> 78.88.48.0/21 <http://78.88.48.0/21>
>>> 91.195.159.5 0 600 100 i
>>> 78.88.56.0/21 <http://78.88.56.0/21>
>>> 91.195.159.5 0 600 100 i
>>> 78.88.64.0/21 <http://78.88.64.0/21>
>>> 91.195.159.5 0 600 100 i
>>> 78.88.72.0/21 <http://78.88.72.0/21>
>>> 91.195.159.5 0 600 100 i
>>> 78.88.80.0/22 <http://78.88.80.0/22>
>>> 91.195.159.5 0 600 100 i
>>> 78.88.84.0/22 <http://78.88.84.0/22>
>>> 91.195.159.5 0 600 100 i
>>> 78.88.88.0/23 <http://78.88.88.0/23>
>>> 91.195.159.5 0 600 100 i
>>> 78.88.90.0/23 <http://78.88.90.0/23>
>>> 91.195.159.5 0 600 100 i
>>> 78.88.92.0/24 <http://78.88.92.0/24>
>>> 91.195.159.5 0 600 100 i
>>> 78.88.93.0/24 <http://78.88.93.0/24>
>>> 91.195.159.5 0 600 100 i
>>> 78.88.96.0/21 <http://78.88.96.0/21>
>>> 91.195.159.5 0 600 100 i
>>> 78.88.106.0/23 <http://78.88.106.0/23>
>>> 91.195.159.5 0 600 100 i
>>> 78.88.108.0/24 <http://78.88.108.0/24>
>>> 91.195.159.5 0 600 100 i
>>> 78.88.109.0/24 <http://78.88.109.0/24>
>>> 91.195.159.5 0 600 100 i
>>> 78.88.110.0/23 <http://78.88.110.0/23>
>>> 91.195.159.5 0 600 100 i
>>> 78.88.112.0/21 <http://78.88.112.0/21>
>>> 91.195.159.5 0 600 100 i
>>>
>>>
>>> [bgp1]R0_SE600#show bgp route neighbor 91.195.159.10
>>> advertised
>>> Address Family: ipv4 unicast
>>> BGP table version is 24923504, local router ID is
>>> 195.66.73.250
>>> Status codes: d damped, h history, > best, i internal
>>> Origin codes: i - IGP, e - EGP, ? - incomplete
>>>
>>> Network Next Hop Metric
>>> LocPrf Weight Path
>>>
>>> 31.11.128.0/17 <http://31.11.128.0/17>
>>> 91.195.159.9 0 600 100
>>> 13000 29314 i
>>> 37.8.192.0/18 <http://37.8.192.0/18>
>>> 91.195.159.9 0 600 100
>>> 13000 29314 i
>>> 77.222.224.0/21 <http://77.222.224.0/21>
>>> 91.195.159.9 0 600 100
>>> 13000 29314 i
>>> 77.222.232.0/21 <http://77.222.232.0/21>
>>> 91.195.159.9 0 600 100
>>> 13000 29314 i
>>> 77.222.240.0/20 <http://77.222.240.0/20>
>>> 91.195.159.9 0 600 100
>>> 13000 29314 i
>>> 78.31.136.0/21 <http://78.31.136.0/21>
>>> 91.195.159.9 0 600 100
>>> 13000 44124 i
>>> 78.88.0.0/20 <http://78.88.0.0/20>
>>> 91.195.159.9 0 600 100
>>> 13000 29314 i
>>> 78.88.16.0/22 <http://78.88.16.0/22>
>>> 91.195.159.9 0 600 100
>>> 13000 29314 i
>>> 78.88.20.0/23 <http://78.88.20.0/23>
>>> 91.195.159.9 0 600 100
>>> 13000 29314 i
>>> 78.88.22.0/23 <http://78.88.22.0/23>
>>> 91.195.159.9 0 600 100
>>> 13000 29314 i
>>> 78.88.24.0/21 <http://78.88.24.0/21>
>>> 91.195.159.9 0 600 100
>>> 13000 29314 i
>>> 78.88.32.0/21 <http://78.88.32.0/21>
>>> 91.195.159.9 0 600 100
>>> 13000 29314 i
>>> 78.88.40.0/23 <http://78.88.40.0/23>
>>> 91.195.159.9 0 600 100
>>> 13000 29314 i
>>> 78.88.43.0/24 <http://78.88.43.0/24>
>>> 91.195.159.9 0 600 100
>>> 13000 29314 i
>>> 78.88.48.0/21 <http://78.88.48.0/21>
>>> 91.195.159.9 0 600 100
>>> 13000 29314 i
>>> 78.88.56.0/21 <http://78.88.56.0/21>
>>> 91.195.159.9 0 600 100
>>> 13000 29314 i
>>> 78.88.64.0/21 <http://78.88.64.0/21>
>>> 91.195.159.9 0 600 100
>>> 13000 29314 i
>>> 78.88.72.0/21 <http://78.88.72.0/21>
>>> 91.195.159.9 0 600 100
>>> 13000 29314 i
>>> 78.88.80.0/22 <http://78.88.80.0/22>
>>> 91.195.159.9 0 600 100
>>> 13000 29314 i
>>> 78.88.84.0/22 <http://78.88.84.0/22>
>>> 91.195.159.9 0 600 100
>>> 13000 29314 i
>>> 78.88.88.0/23 <http://78.88.88.0/23>
>>> 91.195.159.9 0 600 100
>>> 13000 29314 i
>>> 78.88.90.0/23 <http://78.88.90.0/23>
>>> 91.195.159.9 0 600 100
>>> 13000 29314 i
>>> 78.88.92.0/24 <http://78.88.92.0/24>
>>> 91.195.159.9 0 600 100
>>> 13000 29314 i
>>> 78.88.93.0/24 <http://78.88.93.0/24>
>>> 91.195.159.9 0 600 100
>>> 13000 29314 i
>>> 78.88.96.0/21 <http://78.88.96.0/21>
>>> 91.195.159.9 0 600 100
>>> 13000 29314 i
>>> 78.88.106.0/23 <http://78.88.106.0/23>
>>> 91.195.159.9 0 600 100
>>> 13000 29314 i
>>> 78.88.108.0/24 <http://78.88.108.0/24>
>>> 91.195.159.9 0 600 100
>>> 13000 29314 i
>>> 78.88.109.0/24 <http://78.88.109.0/24>
>>> 91.195.159.9 0 600 100
>>> 13000 29314 i
>>> 78.88.110.0/23 <http://78.88.110.0/23>
>>> 91.195.159.9 0 600 100
>>> 13000 29314 i
>>> 78.88.112.0/21 <http://78.88.112.0/21>
>>> 91.195.159.9 0 600 100
>>>
>>> 13000 29314 i
>>>
>>> [bgp1]R0_SE600#
>>>
>>>
>>> the first one is strange, because it looks like AS
>>> path is missing.
>>> Is it a random bug ?
>>>
>>> Regards,
>>> Marcin
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