4.18 Carrier Supporting Carrier - when to use send-label?

Hi, when to use send-label? why send-label wasn't used for R2 <->XR2 even though they are forming vpnv4 BGP?

 

in "4.17 MPLS L3VPN Inter-AS Option C w/ iBGP + Label" - why send-label was used between Route Reflectors R5 <-> XR2 vpnv4 BGP?

Comments

  • Labels are swapped between CSC-CEs (R3, R4) and CSC-PEs (R1, XR1) in CSC design

    *Note in CSC design XR supports only BGP method for sending labels across eBGP boundary in IOS you can also use IGP+LDP to do this

    Here is relevant bits of the task

    Configure IPv4 Labeled Unicast BGP peerings as follows:
    o R1 and XR1 are in AS 17819.
    o R3 and R4 are in AS 100.
    o R1 should form an IPv4 Unicast EBGP peering with R3.
    o XR1 should form an IPv4 Unicast EBGP peering with R4.




    Second question shows:

    "Traceroutes between these networks should indicate that a single end-to-end
    Label Switch Path is used."

    Inter-AS Option C (next-hop-unchanged configured on the RRs R5 and XR2)

    On Inter-AS boundary between R1-XR1 we need labels across this transit link hence eBGP IPv4 unicast + Label, then in both AS100 and AS200 we're using IPv4 unicast iBGP + Label to build a single MPLS LSP end-to-end from each PE in each AS this replaces any need for BGP>IGP redistribution on the ASBRs (R1 and XR1) and ultimately IGP+LDP to build the single LSP

    On Wed, Oct 1, 2014 at 4:23 PM, pennboy77 <[email protected]> wrote:

    Hi, when to use send-label? why send-label wasn't used for R2 <->XR2 even though they are forming vpnv4 BGP?

     

    in "4.17 MPLS L3VPN Inter-AS Option C w/ iBGP + Label" - why send-label was used between Route Reflectors R5 <-> XR2 vpnv4 BGP?




    INE - The Industry Leader in CCIE Preparation

    http://www.INE.com



    Subscription information may be found at:

    http://www.ieoc.com/forums/ForumSubscriptions.aspx

Sign In or Register to comment.