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MPLS BGP Routes hidden

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  • 1.  MPLS BGP Routes hidden

    Posted 01-18-2019 06:49

    Hi Everyone,

     

    I have a MPLS network which is using AS6500 for iBGP.

    I am using an SRX300.
    After further checking, it seems like I am not receiving routes from other iBGP neighbor.

    These routes are hidden.

     

    For example...

     

    10.15.0.0/16 [BGP/170] 00:52:49, MED 0, localpref 100, from 10.60.0.10
    AS path: 64620 I, validation-state: unverified
    Unusable

     

    When I perform the show route hidden extensive, the output for the above route is...

     

    10.15.0.0/16 (1 entry, 0 announced)
    BGP Preference: 170/-101
    Route Distinguisher: 64512:100
    Next hop type: Unusable, Next hop index: 0
    Address: 0x16a1658
    Next-hop reference count: 101
    State: <Secondary Hidden Int Ext ProtectionCand>
    Local AS: 65000 Peer AS: 65000
    Age: 53:49 Metric: 0
    Validation State: unverified
    Task: BGP_65000.10.60.0.10
    AS path: 64620 I (Originator)
    Cluster list: 10.60.0.10
    Originator ID: 10.255.30.34
    Communities: target:64512:100
    Import Accepted
    VPN Label: 18
    Localpref: 100
    Router ID: 10.255.30.1
    Primary Routing Table bgp.l3vpn.0
    Indirect next hops: 1
    Protocol next hop: 10.255.30.34
    Label operation: Push 18
    Label TTL action: prop-ttl
    Load balance label: Label 18: None;
    Indirect next hop: 0x0 - INH Session ID: 0x0

     

     

    Can someone please guide me on how to overcome this issue?

    Do note that this PE is a route-reflector-client.

    Thanks.

     

     

     

     

     

     

     



  • 2.  RE: MPLS BGP Routes hidden

    Posted 01-18-2019 07:19

    Hello,

    For 10.15.0.0/16 route to be unhidden, 10.255.30.34 route must be present in inet.3 table.

    And inet.3 table is populated by either LDP, RSVP or BGP-LU.

    If You don't have at least 1 of these protocols enabled, then it's high time to do it, otherwise Your MPLS services won't work.

    HTH

    Thx

    Alex



  • 3.  RE: MPLS BGP Routes hidden

    Posted 01-20-2019 13:20

    Hi Alex,

     

    Thanks for the response.
    I am running MPLS TE via RSVP in my network which also consist of Cisco network devices.

    I have attached the simplified version of the network diagram in this post.

    Each SRX has only the LSP and BGP to the Main_PE device (which is a cisco 6500).

    The Cisco 6500 is acting as a route-reflector.

    You are right in the sense that there is no 10.255.30.34 in my inet.3 table.

    I only have the Main_PE device in my inet.3 table.

    The reason why I have route-reflectors is because the number of PEs that I will have will be expanding and for scalability purpose, route-reflector was implemented.

    This would be an issue with the route-reflector right?

     

    Regards,

    Han

    iBGP Issue.png


    #MPLS
    #route-reflector
    #rsvp


  • 4.  RE: MPLS BGP Routes hidden
    Best Answer

    Posted 01-20-2019 22:47

    Hello,

     


    @cHrome08 wrote:

     

    You are right in the sense that there is no 10.255.30.34 in my inet.3 table.

    I only have the Main_PE device in my inet.3 table.

    The reason why I have route-reflectors is because the number of PEs that I will have will be expanding and for scalability purpose, route-reflector was implemented.

    This would be an issue with the route-reflector right?

     

     

     


     

    I would say this is an issue with Your network architecture.

    The RR is clearly doing its job and reflecting the L3VPN route WITHOUT changing the nexthop.

    Which is the default and proper behaviour for iBGP L3VPN RR. And then You would need the end-to-end, or "full-span", or PE-to-PE LSP for the L3VPN to work properly.

    You may get away with curent "half-span" LSP but then You need to :

    1/ make RR to change nexthop to self, and

    2/ configure all VRFs on the RR

     

    HTH

    Thx

    Alex

     



  • 5.  RE: MPLS BGP Routes hidden

    Posted 01-21-2019 18:42

    Hi Alex,

     

    Thanks for pointing me to the right direction.

    It seems like the route-reflector command was not reflecting the routes from iBGP neighbor.

    Its only reflecting the routes from other eBGP neighbor.

    I just had to modify the config from...

     

    address-family vpnv4

    neighbor PeerGroup2 send-community extended

     neighbor PeerGroup2 route-reflector-client
    neighbor PeerGroup2 next-hop-self

    exit address-family

     

    to

     

    address-family vpnv4

    neighbor PeerGroup2 send-community extended

     neighbor PeerGroup2 route-reflector-client
    neighbor PeerGroup2 next-hop-self all

    exit address-family

     

     

    The "all" command on the cisco 6500 will route-reflect every routes learned from eBGP and iBGP neighbor and that solves the issue.

    Thanks for your help.


    Regards,

    Han