HP 6125XLG R2306-HP 6125XLG Blade Switch TRILL Configuration Guide - Page 13

Step Command 6. Enter Ethernet or aggregate interface view. interface interface-type interface-number 7. Configure the minimum LSP interval and the maximum number of LSPs transmitted per trill timer lsp interval [ count count ] time. Remarks N/A By default, the minimum LSP interval is 10 milliseconds, and the maximum number of LSPs transmitted per time is 5. Configuring distribution trees In a TRILL network, RBs compute distribution trees according to the LSDB, and use the distribution trees to guide the forwarding of multicast, broadcast, and unknown unicast frames. An RB with a higher priority is selected as the root bridge of a distribution tree. An LSP carries distribution tree information that includes the number of distribution trees that the RB wants all RBs to compute, the maximum number of distribution trees that the RB can compute (this number is fixed at 15), and the number of distribution trees that the RB has computed. An RB determines the number of distribution trees to compute (n) as follows: select the lower value between the number of distribution trees that the highest-priority RB wants all RBs to compute and the smallest value of the maximum number of distribution trees that each RB can compute. From the nickname list in the LSP advertised by the RB with the highest priority, the first n nicknames comprise the root bridge list that the local RB uses to compute distribution trees. TRILL selects distribution trees for forwarding multicast, broadcast, and unknown unicast frames based on the VLANs that the frames belong to. Because the topologies of TRILL distribution trees are different, traffic can be load-shared. However, equal-cost links are not used for load-sharing. When N equal-cost links exist in the network, each TRILL distribution tree selects the link with the largest pseudo node ID for forwarding packets. As shown in Figure 6, two equal-cost links exist between RB 1 and RB 3. Assume the link directly connecting RB 1 to RB 3 has the largest pseudo node ID. Both the TRILL distribution tree rooted at RB 3 and the TRILL distribution tree rooted at RB 4 select the link. Figure 6 Multicast ECMP RB 3 RB 1 Cost = 3 RB 2 Cost = 1 RB 4 TRILL distribution trees support Equal Cost Multiple Path (ECMP), also known as multicast ECMP. When multicast ECMP is enabled, TRILL assigns equal-cost links to different TRILL distributions trees. This improves the load sharing performance. 10