Routing
Highlighted
Routing

setting a local-preference for a single network

‎05-27-2020 10:19 AM

Hello I am having an issue where traffic to a public subnet lets say 10.10.10.0/24 is always preferred to go out of my router 3 to my ISP3.  The data goes out but does not reach the destination.  A traceroute goes all the way to where that public subnet's ip 20.10.0.1/24 edge is and then dies.  From the 20.10.0.1/24 they can reach my router 3 edge IP 40.10.0.1/24 and they can reach the advertised subnet 50.10.0.0/24 without issue.  But if the traceroute or ping comes from 10.10.10.0/24 hosted under 20.10.0.1/24 it dies in the middle of ISP3s network.  we have opened a ticket with ISP3 but they have not been much help in the matter.  I have 2 other routers with two other ISPs and I would like to try and just work around this problem by setting a local-preference for network 50.10.0.0/24 to go out ISP3 to reach 10.10.10.0/24 but I am not that familiar with BGP configurations. 

 

Attached is the configuration on router 1 to ISP1 I would like to modify.  The configuration on router 3 is virtual identical barring the local IPs and AS number for the ISP3.

If there is a part of the configuration I have stripped out you need to answer the question please let me know. 

 

 

5 REPLIES 5
Highlighted
Routing

Re: setting a local-preference for a single network

‎05-27-2020 10:37 AM

Hi William,

 

The attachment is missing I suppose, can you recheck?

 

//Nex

Highlighted
Routing

Re: setting a local-preference for a single network

[ Edited ]
‎05-27-2020 12:30 PM

Hmm uploading a txt file to the thread isn't working. I uploaded it to my google drive

https://drive.google.com/file/d/1MV0CiHrQ9ygRf3xGz81FeL3Uh6pBQVRj/view?usp=sharing

 

Highlighted
Routing

Re: setting a local-preference for a single network

‎05-27-2020 08:29 PM

I am seeing a list of command outputs on the provided link to drive, I did not find the config snippet.

 

//Nex

Highlighted
Routing

Re: setting a local-preference for a single network

‎05-27-2020 08:50 PM

Hi William,

 

The file only has outputs for few show commands. Can you please attach the config snippet as well ?

 

BR,

Vishal

Highlighted
Routing

Re: setting a local-preference for a single network

‎05-27-2020 10:15 PM

Hello,

 


@williamgeiger85 wrote:

 I have 2 other routers with two other ISPs and I would like to try and just work around this problem by setting a local-preference for network 50.10.0.0/24 to go out ISP3 to reach 10.10.10.0/24 but I am not that familiar with BGP configurations. 

 

 

Setting Local Preference/LP on eBGP peering does not work, as per BGP standards.

You need to add prepending for this prefix when advertising it to ISP3, or deaggregate it when advertising to ISP1/ISP2, or, if ISP3 supports setting LP inside its own network based on community, set an appropriate community outbound to ISP3.

Example of ISP policy using community-based LP adjust on receipt can be found here

https://www.gin.ntt.net/support-center/policies-procedures/routing/

 

HTH

Thx

Alex

_____________________________________________________________________

Please ask Your Juniper account team about Juniper Professional Services offerings.
Juniper PS can design, test & build the network/part of the network as per Your requirements

+++++++++++++++++++++++++++++++++++++++++++++

Accept as Solution = cool !
Accept as Solution+Kudo = You are a Star !