Moving from Narrow to Wide Metrics in Three Steps
This method is longer, but it sidesteps the problem of doubling the size of your LSDB. The steps to do this are as follows Step 1. Configure all routers to advertise only old-style TLVs but accept both old and new using the command metric-style narrow transition. Step 2. Configure all routers to advertise new-style TLVs and accept both using the command metric-style wide transition. Step 3. Configure all routers to advertise new-style TLVs and accept only new-style TLVs using the command...
Tools for Troubleshooting Mpls Te Problems
This section provides a quick overview of some of the commands that are useful for troubleshooting MPLS TE problems. Table 11-3 summarizes these commands. Not all debug or show commands are shown here there are too many to list. However, these are the major ones. Table 11-3. Useful Commands for MPLS TE Troubleshooting Table 11-3. Useful Commands for MPLS TE Troubleshooting This command can be used to verify the different configurations on any LSR regardless of the LSR's role. show mpls...
Router E Is Configured with a Metric of
Another thing you can do is set the absolute tunnel metric, which assigns the same cost to the tunnel and all nodes behind the tunnel. Table 5-11 shows Router A's routing table if you configure tunnel mpls traffic-eng autoroute metric absolute 17 on Tunnel0. Only IS-IS supports tunnel mpls traffic-eng autoroute metric absolute if you configure absolute metrics on an OSPF network, it's just ignored. Table 5-11. Router A's Routing Table After Tunnel0 Is Configured with an Table 5-11. Router A's...
Figure 719 NHop Versus NNHop Backup Tunnels
Example 7-32 shows that both primary LSPs are backed up using NNHop tunnel2, even though two backup tunnels are available one to the NHop and the second to the NNHop. This can be observed by executing the show mpls traffic-eng fast-reroute database command. Example 7-32 NNHop Tunnel2 Being Used for Protection 12008a show mpls traffic-eng fast-reroute database Tunnel head fast reroute information Prefix Tunnel In-label Out intf label LSP identifier In-label Out intf label 4.4.4.4 1 1520 16 PO1 0...
Mpls Te
As mentioned in the introductory section, the TE MIB is defined in draft-ietf-mpls-te-mib. Appendix B provides links to the Cisco online documentation for the MPLS TE MIB. The following tables constitute the TE MIB The mplsTunnelCRLDPResTable is not supported in the current Cisco implementation, because Cisco's MPLS TE does not support CR-LDP. The following sections examine each of the TE MIB tables in detail. The purpose of the mplsTunnelTable is to create or modify tunnels. Using this table,...
Underlying layer
The Underlying Layer shown in Figure 8-1 is any Layer 2 that supports MPLS, such as Ethernet, Frame Relay, or ATM. Figure 8-2 shows a Network Management System (NMS) attached to a sample network. You can either have a dedicated management network that attaches to each device you want to monitor, or simply place the NMS somewhere on your network and all management traffic to traverse the backbone. NMS links (subnet 7.1.5.Q 24J NMS links (subnet 7.1.5.Q 24J In the sample network shown in Figure...
LSP Scalability
The most important issue on the mind of any self-respecting network engineer is scalability How well does this scale The answer to this question depends on where you want to put your TE cloud. In this chapter's sample network architecture, three choices exist Somehow involving the DRs in the equation All three of these choices scale the same way (a full mesh is n * (n - 1) LSPs), but their scaling numbers are different. CRs outnumber WRs, which means more TE tunnels, which means more signalling...
Seconds which is 3041 days
This is approximately what you saw in the CLI of the show mpls traffic-eng tunnel output. mplsTunnelStateTransitions This variable represents the number of times that the tunnel has changed state. You can observe this on the CLI using the show mpls traffic-eng tunnels tunnel2 statistics command, as demonstrated in Example 8-58. Example 8-58 Determining the Number of Times the Tunnel Has Changed State mpls-12008a show mpls traffic-eng tunnels tunnel2 statistics Tunnel2 (Destination 12.12.12.12...
Figure 49 Two TE Tunnels Across the Top Link
When a reoptimization happens on either of these tunnels (periodic, manually triggered, or because of the link-up event), whichever tunnel happens to reoptimize puts itself on the other link. Assume that it's the tunnel. Figure 4-10 shows what things look like after that reoptimization. Figure 4-10. B Tunnel Reoptimized to the Bottom Link Figure 4-10. B Tunnel Reoptimized to the Bottom Link But what if you didn't want the B E tunnel to reoptimize for some reason If that tunnel had been...
Example 101 Output of show ip cef nonrecursive
Example 10-2 shows the routing table that matches up to these nonrecursive prefixes. Example 10-2 Routing Table for Example 10-1 Codes C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area * - candidate default, U - per-user...
Traffic Engineering with MPLS
By Eric Osborne CCIE 4122, Ajay Simha CCIE 2970 Publisher Cisco Press Pub Date July 17, 2002 ISBN 1-58705-031-5 Pages 608 Slots 2 Design, configure, and manage MPLS TE to optimize network performance. Almost every busy network backbone has some congested links while others remain underutilized. That's because shortest-path routing protocols send traffic down the path that is shortest without considering other network parameters, such as utilization and traffic demands. Using Traffic Engineering...
Figure 43 Simple Network Topology Demonstrating the CSPF Algorithm
In the topology shown in Figure 4-3, Router A wants to build a TE tunnel to Router D with a bandwidth of 60 Mbps. Each link lists its metric (the same as in Figure 4-1) and its available bandwidth. Without taking bandwidth into account, Router A's best path to Router D is A B C D, with a total cost of 12. But the path A B C D doesn't have 60 Mbps available. CSPF needs to calculate the shortest path that has 60 Mbps available. This is actually quite simple. The steps for the CSPF algorithm are...
MPLS Terminology
Before jumping into MPLS concepts, it is a good idea to familiarize yourself with the terminology and lingo used in MPLS. Table 2-1 defines some common MPLS-related terms you must know in order to understand the concepts in this chapter and book. A router that is closer to the source of a packet, relative to another router. A router that is farther from the source of a packet, relative to another router. As a packet traverses a network, it is switched from an upstream router to its downstream...
How SPF Works
In a link-state routing protocol, each router knows about all other routers in a network and the links that connect these routers. In OSPF, this information is encoded as Link-State Advertisements (LSAs) in IS-IS, this information is Link-State Packets (LSPs). This chapter does not discuss the differences between these two protocols. See Appendix B,CCO and Other Resources, for more information. Because the acronym LSP also stands for Label-Switched Path, the unit of information a router uses to...
