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  • 1.  route-server-client routes from IBGP peer to EBGP peer

    Posted 13 days ago

    Hi Team,

    We have some EBGP peers who have full mesh MPEBGP neighborship and advertising routes to each other, we are using policies to block advertisement of EBGP to EBGP.

    We have RR and IBGP peers in different network where they have normal MPBGP Peers.

    We are trying to consolidate EBGP neighbors with RR to get rid of full mesh MPEBGP. We used command route-server-client and it worked properly except one condition.

    Routes from IBGP-->RR-->EBGP are getting hidden at EBGP neighbor because of "Hidden reason: Empty path on external peer". This is happening only for local routes direct/static etc., bgp received routes are getting installed properly.

    Is this route-server-client feature broken? or we can only use this for EBGP-EBGP scenario?

    Note: First time posting in Juniper Forum, please pardon my mistakes. 



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    AFTAB AHMED
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  • 2.  RE: route-server-client routes from IBGP peer to EBGP peer

    Posted 12 days ago

    You probably have a policy setting «next hop self» for all routes including reflected ones, on the iBGP outbound policy of your RR.

    Very common mistake.

    Please post this policy so we can point it :)



    ------------------------------
    Olivier Benghozi
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  • 3.  RE: route-server-client routes from IBGP peer to EBGP peer

    Posted 11 days ago

    Thanks for the reply. 

    «next hop self» is not applied. 

    We are trying to make communication from IBGP Peer to EBGP Peer via RR. The Propagation for BGP routes received from CE is fine. The propagation for Connected/Static routes  from EBGP Peer to IBGP Peer is fine.  The propagation for Connected/Static routes  from IBGP Peer to EBGP Peer is broken.

    As RR doesn't append AS while advertising routes received from IBGP peer, Connected/Static routes received from IBGP Peers are advertised to EBGP Peers as is.

    This results in "Empty path on external peer" error on EBGP Client.

    Below bgp configuration for your reference from RR router.

    set protocols bgp group RR-CLIENT-EBGP type external
    set protocols bgp group RR-CLIENT-EBGP multihop ttl 255
    set protocols bgp group RR-CLIENT-EBGP route-server-client
    set protocols bgp group RR-CLIENT-EBGP local-address 90.0.2.1
    set protocols bgp group RR-CLIENT-EBGP family inet unicast
    set protocols bgp group RR-CLIENT-EBGP family inet-vpn unicast
    set protocols bgp group RR-CLIENT-EBGP family inet6-vpn unicast
    set protocols bgp group RR-CLIENT-EBGP family l2vpn auto-discovery-only
    set protocols bgp group RR-CLIENT-EBGP family l2vpn signaling
    set protocols bgp group RR-CLIENT-EBGP family inet-mvpn signaling
    set protocols bgp group RR-CLIENT-EBGP neighbor 90.0.2.0 description MX480-PE1
    set protocols bgp group RR-CLIENT-EBGP neighbor 90.0.2.0 peer-as 18491
    set protocols bgp group RR-CLIENT-EBGP neighbor 100.100.0.161 description MX104-R6-PE3
    set protocols bgp group RR-CLIENT-EBGP neighbor 100.100.0.161 peer-as 19804
    set protocols bgp group RR-CLIENT-EBGP neighbor 100.100.0.170 description MX104-R5-PE5
    set protocols bgp group RR-CLIENT-EBGP neighbor 100.100.0.170 peer-as 24232

    set protocols bgp group RR-CLIENT-IBGP type internal
    set protocols bgp group RR-CLIENT-IBGP multihop ttl 255
    set protocols bgp group RR-CLIENT-IBGP local-address 90.0.2.1
    set protocols bgp group RR-CLIENT-IBGP family inet-vpn unicast
    set protocols bgp group RR-CLIENT-IBGP family inet-vpn multicast
    set protocols bgp group RR-CLIENT-IBGP family inet6-vpn unicast
    set protocols bgp group RR-CLIENT-IBGP family l2vpn auto-discovery-only
    set protocols bgp group RR-CLIENT-IBGP family l2vpn signaling
    set protocols bgp group RR-CLIENT-IBGP family inet-mvpn signaling
    set protocols bgp group RR-CLIENT-IBGP family inet6-mvpn signaling
    set protocols bgp group RR-CLIENT-IBGP family inet-mdt signaling
    set protocols bgp group RR-CLIENT-IBGP cluster 90.0.2.1
    set protocols bgp group RR-CLIENT-IBGP neighbor 90.0.2.2 description MX480-PE2
    set protocols bgp group RR-CLIENT-IBGP neighbor 90.0.2.4 description MX104-R6-PE4
    set protocols bgp group RR-CLIENT-IBGP neighbor 90.0.2.6 description MX104-R5-PE6



    ------------------------------
    AFTAB AHMED
    ------------------------------



  • 4.  RE: route-server-client routes from IBGP peer to EBGP peer

    Posted 11 days ago

    OK, very simple, you must

    delete protocols bgp group RR-CLIENT-EBGP route-server-client

    as an eBGP peer isn't expected to be a route reflector client (iBGP routes are always re-advertised to eBGP peers).



    ------------------------------
    Olivier Benghozi
    ------------------------------



  • 5.  RE: route-server-client routes from IBGP peer to EBGP peer

    Posted 7 days ago

    if we remove "route-server-client" then RR will start considering EBGP Peers as non-client, and RR AS will be prepended and next-hop change will occur.

    I guess this knob needs attention from Juniper team and there should be Note/Disclaimer that it will not work in the condition mentioned in Post 2.



    ------------------------------
    AFTAB AHMED
    ------------------------------



  • 6.  RE: route-server-client routes from IBGP peer to EBGP peer

    Posted 7 days ago

    OK, but the concept of  route-server (not route-reflector) is designed to reflect eBGP to eBGP: the classical use case being notably on an Internet Xchange LAN with plenty of eBGP peers. It's not designed to mix iBGP and eBGP together.

    You might try to use a policy to add (prepend) an AS toward the eBGP peers...



    ------------------------------
    Olivier Benghozi
    ------------------------------