D-Link DGS-6600-48TS Configuration Guide - Page 354

Volume 5-Multiprotocol Label Switching / Chapter 33-Multiprotocol Label Switching (MPLS) Configuration Examples Step Router Packet Type and Description Router Action (Receive or Send) 1 R1 Echo request: With a target FEC pointing 1. Sets the TTL of the labe stack to 1 to R4 and to a downstream mapping. 2. Sends the request to R2 2 R2 Echo to reply. 1. Receives the packet with a TTL =1 2. Processes the User Datagram Protocol (UDP) packet as an echo request 3. Finds a downstream mapping and replies to R1 with its own downstream mapping, based on the incoming label 3 R1 Echo request: With the same target FEC 1. Sets the TTL of the label stack to 2 and the downstream mapping received in 2. Sends the request to R2 the echo reply from R2. 4 R2 Echo request. 1. Receives the packet with a TTL=2 2. Decrements the TTL 3. Forwards the echo request to R3 5 R3 Echo reply. 1. Receives the packet with TTL=1 2. Processes the UDP packet as an echo request 3. Finds a downstream mapping and replies to R1 with its own downstream mapping based on the incoming label 6 R1 Echo request: With the same target FEC and the downstream mapping received in the echo reply from R3. 1. Sets the TTL of the packet to 3 2. Sends the request to R2 7 R2 Echo request 1. Receives the packet with a TTL=3 2. Decrements the TTL 3. Forwards the echo request to R3 8 R3 Echo request 1. Receives the packet with TTL=2 2. Decrements the TTL 3. Forwards the echo request to R4 9 R4 Echo reply 1. Receives the packet with TTL = 1 2. Processes the UDP packet as an MPLS echo request 3. Finds a downstream mapping and also finds that the router is the egress router for the target FEC 4. Replies to R1 Configuration Examples MPLS, LDP (Dynamic Label) Configuration Example Configuring the MPLS protocol in R1, R2 and R3. The MPLS label is learned by LDP protocol. The DGS-6600 router can forward packets by the learned label information. DGS-6600 Configuration Guide 354