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BGP aggregates not advertising

Michael Gehrmann
Level 1
Level 1

‎07-31-2014 05:50 PM

Hi Everyone,

Trying to send out aggregates to upstream ISP to summarise longer prefixes i.e. /24 to summarise /27-29.

 

I have bgp aggregates configured;

router bgp 17477
 bgp router-id 124.47.128.44
 bgp log neighbor changes detail
 address-family ipv4 unicast
  network 0.0.0.0/0
  aggregate-address 124.47.128.0/18
  aggregate-address 124.47.132.0/24
  aggregate-address 124.47.136.0/24
  aggregate-address 124.47.137.0/24
  aggregate-address 124.47.138.0/24
  aggregate-address 124.47.139.0/24
  aggregate-address 124.47.153.0/24
  aggregate-address 124.47.154.0/24
  aggregate-address 124.47.159.0/24
  aggregate-address 124.47.161.0/24
  redistribute connected
  redistribute static

Of which the 124.47.128.0/18 works ok.

My route-policy looks like this;

route-policy BGP-Export
  if destination in RFC1918 then
    drop
  endif
  if destination in IPV4-Ranges and as-path is-local then
    done
  endif
  if destination in BYOP-IPv4-Address and extcommunity rt matches-any Customer-Routes then
    done
  endif
  if destination in IPv4-Aggregate then
    done
  endif
end-policy
!

The aggregate prefixes are contained in the prefix-set IPv4-Aggregate.

RP/0/RSP0/CPU0:asr9006-01# sho bgp 124.47.136.0/24 brief               
Fri Aug  1 10:49:16.593 EST

Status codes: s suppressed, d damped, h history, * valid, > best
              i - internal, r RIB-failure, S stale
Origin codes: i - IGP, e - EGP, ? - incomplete
   Network            Next Hop            Metric LocPrf Weight Path
*> 124.47.136.0/24    0.0.0.0                            32768 i

 

I've done this yet no aggregates except for the /18 are advertised? Any ideas? What am I doing wrong?

Would prefer to use aggregates instead of static routes. And yes contributing routes are present.

 

 

 

Labels:
0 Helpful
5 Replies 5

bhnegi
Cisco Employee
Cisco Employee

‎08-02-2014 05:55 AM

When you say contributing routes are present I assume you mean more specific routes. Are they in routing table or bgp table?

http://www.cisco.com/c/en/us/td/docs/routers/asr9000/software/routing/command/reference/rrasr9kbgp.html#wp1358259

 

Use the aggregate-address command without optional arguments to create an aggregate entry in the BGP routing table if any more-specific BGP routes are available that fall in the specified range.

Best Regards,

Bheem

0 Helpful

Michael Gehrmann
Level 1
Level 1
In response to bhnegi

‎08-03-2014 05:09 PM

Yes, the routes are in the bgp table. As you can see from my config I have the aggregates configured without options and see the aggregate route in the bgp table.

RP/0/RSP0/CPU0:asr9006-01#sh bgp 124.47.136.0/24 longer-prefixes
Mon Aug  4 09:58:46.511 EST
BGP router identifier 124.47.128.44, local AS number 17477
BGP generic scan interval 60 secs
BGP table state: Active
Table ID: 0xe0000000   RD version: 251380169
BGP main routing table version 251380169
BGP scan interval 60 secs

Status codes: s suppressed, d damped, h history, * valid, > best
              i - internal, r RIB-failure, S stale
Origin codes: i - IGP, e - EGP, ? - incomplete
   Network            Next Hop            Metric LocPrf Weight Path
*> 124.47.136.0/24    0.0.0.0                            32768 i
*> 124.47.136.0/28    0.0.0.0                  0         32768 ?
*                     124.47.136.6             0    110      0 65000 ?
*                     124.47.136.6             0    108      0 65000 ?
* i                   203.110.136.253               100      0 i
*> 124.47.136.16/28   124.47.136.6             0    110      0 65000 ?
*                     124.47.136.6             0    108      0 65000 ?
*> 124.47.136.32/32   124.47.136.6             0    110      0 65000 ?
*> 124.47.136.33/32   124.47.136.6             0    108      0 65000 ?
*> 124.47.136.37/32   124.47.136.6                  110      0 65000 64512 64513 64514 ?
*                     124.47.136.6                  108      0 65000 64512 64513 64514 ?
*> 124.47.136.38/32   124.47.136.6                  110      0 65000 64512 64513 64514 ?
*                     124.47.136.6                  108      0 65000 64512 64513 64514 ?
*> 124.47.136.44/30   124.47.136.6                  110      0 65000 64512 64513 64514 ?
*                     124.47.136.6                  108      0 65000 64512 64513 64514 ?
*> 124.47.136.48/28   124.47.136.6                  110      0 65000 64512 ?
*                     124.47.136.6                  108      0 65000 64512 ?
*> 124.47.136.64/28   124.47.136.6                  110      0 65000 64512 64513 ?
*                     124.47.136.6                  108      0 65000 64512 64513 ?
*> 124.47.136.80/28   124.47.136.6                  110      0 65000 64512 64513 64514 ?
*                     124.47.136.6                  108      0 65000 64512 64513 64514 ?
*> 124.47.136.96/28   124.47.136.6                  110      0 65000 64512 64513 64514 ?
*                     124.47.136.6                  108      0 65000 64512 64513 64514 ?
*> 124.47.136.112/28  124.47.136.6                  110      0 65000 64512 64513 64514 64515 ?
*                     124.47.136.6                  108      0 65000 64512 64513 64514 64515 ?
*> 124.47.136.113/32  124.47.136.6                  110      0 65000 64512 64513 64514 64515 ?
*                     124.47.136.6                  108      0 65000 64512 64513 64514 64515 ?
*> 124.47.136.114/32  124.47.136.6                  110      0 65000 64512 64513 64514 64515 ?
*                     124.47.136.6                  108      0 65000 64512 64513 64514 64515 ?
*> 124.47.136.115/32  124.47.136.6                  110      0 65000 64512 64513 64514 64515 ?
*                     124.47.136.6                  108      0 65000 64512 64513 64514 64515 ?
*> 124.47.136.116/32  124.47.136.6                  110      0 65000 64512 64513 64514 64515 ?
*                     124.47.136.6                  108      0 65000 64512 64513 64514 64515 ?
*> 124.47.136.128/28  124.47.136.6                  110      0 65000 64512 64513 64514 64515 ?
*                     124.47.136.6                  108      0 65000 64512 64513 64514 64515 ?
*> 124.47.136.144/30  124.47.136.6                  110      0 65000 64512 64513 64514 ?
*                     124.47.136.6                  108      0 65000 64512 64513 64514 ?
*> 124.47.136.148/30  124.47.136.6                  110      0 65000 64512 64513 64514 ?
*                     124.47.136.6                  108      0 65000 64512 64513 64514 ?

Processed 20 prefixes, 39 paths

Here is the prefix-set I'm using for the route-policy.

prefix-set IPv4-Aggregate
  124.47.136.0/24,
  124.47.137.0/24,
  124.47.153.0/24,
  124.47.154.0/24
end-set
!

I'm on IOS-XR 4.2.1

0 Helpful

bhnegi
Cisco Employee
Cisco Employee
In response to Michael Gehrmann

‎08-03-2014 07:40 PM

Ok so other than /18 you do see 124.47.136.0/24 as you have specific routes for it in bgp table.

Can you check if you have more specific routes in bgp table for 124.47.137.0/24,
 124.47.153.0/24 and 124.47.154.0/24?

Also can you share you full running config from ASR9k.

Best Regards,

Bheem

0 Helpful

Michael Gehrmann
Level 1
Level 1
In response to bhnegi

‎08-03-2014 08:18 PM

Thanks for your interest.

It turns out I was editing the wrong policy for the neighbor. Apologies for the inconvenience.

 neighbor-group Internet
  remote-as xxxx
  description "Internet Transit"
  address-family ipv4 unicast
   weight 200
   route-policy BGP-Import in
   route-policy BGP-IPv4-Export out
   remove-private-AS
   soft-reconfiguration inbound always
  !
 !
0 Helpful

bhnegi
Cisco Employee
Cisco Employee
In response to Michael Gehrmann

‎08-04-2014 03:56 AM

Hi Michael,

Glad to hear that everything worked out well for you.

Best Regards,

Bheem

0 Helpful
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