Description

ECMP route not showing on L3VPN/BGP-LU routes.

Symptoms

ECMP route not showing on L3VPN routes with iBGP-LU, expect see two paths of et-0/0/1 and et-0/1/1, but only see one path.

e.g.

sanketr@D-BLF05RU25-JMX304-LJ31-RE0> show route table AL_304_IPVPN_IPIC-h

 

AL_304_IPVPN_IPIC-h.inet.0: 114 destinations, 220 routes (114 active, 0 holddown, 0 hidden)

@ = Routing Use Only, # = Forwarding Use Only

+ = Active Route, - = Last Active, * = Both

: <snip>

172.31.141.0/24   *[BGP/170] 01:36:06, localpref 100, from 10.127.217.241

                     AS path: 65501 I, validation-state: unverified

                   > to 192.168.100.230 via et-0/1/1.0, Push 791, Push 147121(top)

                   [BGP/170] 01:36:06, localpref 100, from 10.116.161.1

                     AS path: 65501 I, validation-state: unverified

                   > to 192.168.100.230 via et-0/1/1.0, Push 791, Push 147121(top)

                   [BGP/170] 01:36:06, localpref 100, from 10.116.161.4

                     AS path: 65501 I, validation-state: unverified

                   > to 192.168.100.230 via et-0/1/1.0, Push 791, Push 147121(top)

 

 

Solution

Added below multipath-resolve option to see ECMP on L3VPN routes.

 

e.g.

pbashurin@mx960-lr17-re0# show | compare

[edit routing-options]

+ resolution {

+   rib bgp.l3vpn.0 {

+     inet-import multipath;

+   }

+ }

[edit policy-options]

+ policy-statement multipath {

+   then multipath-resolve;

+ }

Modification History

2023-12-12 : Article Created

Related Information

https://junipernetworks.sharepoint.com/sites/nok/technology/routing/Lists/Community%20Discussion/Flat.aspx?RootFolder=/sites/nok/technology/routing/Lists/Community%20Discussion/Multipath%20@iBGP-LU%20is%20not%20working%20w%20L3VPN%20%20Juniper%20Case%202021-0412-0474&FolderCTID=0x012002003F9B5D58217F8C46B050BFDCB1D640A7