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New Member

BGP aggregates not advertising

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.

 

 

 

Everyone's tags (1)
5 REPLIES
Cisco Employee

When you say contributing

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

New Member

Yes, the routes are in the

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

Cisco Employee

Ok so other than /18 you do

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

New Member

Thanks for your interest.

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
  !
 !
Cisco Employee

Hi Michael,Glad to hear that

Hi Michael,

Glad to hear that everything worked out well for you.

Best Regards,

Bheem

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