Junos
Junos

How to show all bgp neighbors a particular route is being advertised to?

‎07-10-2019 02:05 PM

My apologies if this has been covered before, but a search did not reveal what I am looking for.

 

Is there a JunOS command that will allow me to search for all bgp neighbors that I am advertising a particular route to?

 

I know that "show route advertising-protocol bgp x.x.x.x" will show me all the routes being advertised to that particular neighbor, but that's not what I'm looking for.

 

Thank you ahead of time!

6 REPLIES 6
Junos

Re: How to show all bgp neighbors a particular route is being advertised to?

‎07-10-2019 08:31 PM

Hi Andrew,

 

Please clarify if this is just a cosmetic requirement or if there is a particular use-case.  The closest to this I've seen is a BMP feature that monitors the RIB-OUT (supported 19.1 onwards) but not a simple command to check the neighbors where a route is advertised.

 

root@R1# set protocols bgp bmp monitor enable route-monitoring rib-out ?
Possible completions:
<[Enter]> Execute this command
post-policy Send post-policy adj-ribs-out route monitoring messages
pre-policy Send pre-policy adj-ribs-out route monitoring messages
| Pipe through a command

 

Hope this helps.

Regards,
-r.

--------------------------------------------------

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Junos
Solution
Accepted by topic author Andrew_P
‎07-11-2019 11:40 AM

Re: How to show all bgp neighbors a particular route is being advertised to?

‎07-10-2019 09:42 PM

Hi Andrew ,

 

You can use the below shell sctipt as an interim solution Smiley Happy 

i have not tested it extenselvely , it take the route advertised as command line argument and gives the result 

 

#!/bin/sh

prefix="$1"
echo "$prefix"
for i in `cli -c "show bgp summary | match Estab" | awk {'print $1'}`
do
echo "$i"
check=`cli -c "show route advertising-protocol bgp $i | grep $prefix" | awk {'print $2'} `
echo "$check"
if [ $check ]
then
echo "Prefix is advertised to $i"
fi
done


To run go to start shell
vi test.sh , paste the script
sh test.sh <prefix>

Eg from Lab :-
% sh test.sh 60.60.60.0

11.11.11.11
60.60.60.0/30
Prefix is advertised to 11.11.11.11
172.26.226.29
60.60.60.0/30
Prefix is advertised to 172.26.226.29

 

Thx

Anish 

If this solves your problem, please mark this post as "Accepted Solution."
Kudos are always appreciated .

Junos

Re: How to show all bgp neighbors a particular route is being advertised to?

‎07-11-2019 10:49 AM

Thank you very much!

 

This is just a case where we were attempting to determine which, if any, bgp neighbors we were advertising a certain route to.

 

I knew I could go look to see the advertised-route to each individual bgp neighbor, but that's very time consuming.

 

I'll give that script a try.  Thanks!

Junos

Re: How to show all bgp neighbors a particular route is being advertised to?

‎07-11-2019 11:30 AM

Not any CLI output that I am aware of. No straightforward command I guess. 

 

Probably you should be condifence in the BGP route selection algorithm and Junos implementation. Whatever neighbor it should be advertising to(usually to RR and EBGP peers), unless it's blocked by a policy, it should just advertise. 


Mengzhe Hu
JNCIE x 3 (SP DC ENT)
Junos

Re: How to show all bgp neighbors a particular route is being advertised to?

‎07-11-2019 11:39 AM

Well, as we all know...how things are *supposed* to work, and whether they do or not is a different thing.  And sometimes, we need to be able to "prove" it to the powers that be, so to speak.

 

If everything always worked perfect, we'd all be out of a job.  Smiley Happy

 

Thank you folks for the suggestions!  I am going to give that script a try as soon as I am able.

Junos

Re: How to show all bgp neighbors a particular route is being advertised to?

‎08-21-2019 11:21 PM
You can use "show route extensive" command see advertise to which BGP group. hope which helps you. 23.0.0.0./21 (1 entry, 1 announced) TSI: KRT in-kernel 23.0.0.0./21 -> {list:172.16.12.38, 172.16.12.42} Page 0 idx 0, (group EBGP_v4 type External) Type 1 val 0x496a3d0 (adv_entry) Advertised metrics: Nexthop: Self AS path: [10] I Communities: 64050:21079 64050:30079