The MPLS WG Archive[Date Prev][Date Next][Thread Prev][Thread Next] [Date Index][Thread Index][Author Index][Subject Index] MPLS Ping question
Hi, There were several discussions about MPLS Ping already, but I could not find the answer to following question about trace-route mode: assume that just before reroute some midpoint LSR X responds with its current downstream information (label, interface, hashing addresses), so MPLS Ping initiator will build a packet meant to go to the old downstream in respect to LSR X. However at the time LSR X gets new MPLS Ping packet (with TTL incremented by one), its hardware will be configured with a new forwarding information and the packet will be forwarded to a new downstream router that will complain about FEC/Label mismatch. Since trace-route fails because of topology change, it should be repeated again. But network operator sending MPLS Ping from ingress router might not know that some LSR along the way just did a reroute, so he would assume that the LSP is broken. How the operator can differentiate between topology changes and broken LSP, since LDP topology changes are not visible to him? Thank you, - Igor Achkinazi _________________________________________________________________ FREE pop-up blocking with the new MSN Toolbar – get it now! http://toolbar.msn.com/go/onm00200415ave/direct/01/ |
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