Frame-Mode MPLS Data Plane Operation

There are three major steps in the propagation of an IP packet across an MPLS backbone. ■ The Ingress Edge-LSR receives an IP packet, classifies the packet into a forward equivalence class (FEC), and labels the packet with the outgoing label stack corresponding to the FEC. For unicast destination-based IP routing, the FEC corresponds to a destination subnet and the packet classification is a traditional Layer 3 lookup in the forwarding table. ■ Core LSRs receive this l..

Load Balancing Across PortChannels

When a switch decides to forward a frame out a PortChannel, the switch must also decide which physical link to use to send each frame. To use the multiple links, Cisco switches load balance the traffic over the links in an EtherChannel based on the switch’s global load-balancing configuration. Load-balancing methods differ depending on the model of switch and software revision. Generally, load balancing is based on the contents of the Layer 2, 3, and/or 4 headers. If load ..

New Features in EIGRP

The sections that follow present several new features that you can use to solve tricky situations you might encounter in EIGRP networks. By using these new features, you can create the most effective design for a particular network. Third-Party Next Hop Numerous problems are addressed by the EIGRP Third Party Next Hop feature. Generally, the Third Party Next Hop feature addresses the situation in which the best next hop to reach a destination is not known via an EIGRP neigh..

Automating Dial Backup

This recipe includes several important features. First, notice that we have configured dial backup using an ISDN BRI interface on this router. So we have to set up the ISDN configuration: Router1(config)#interface BRI0/0 Router1(config-if)#isdn switch-type basic-ni Router1(config-if)#isdn spid1 800555123400 5551234 Router1(config-if)#isdn spid2 800555123500 5551235 This site is connected to a National ISDN switch. So we have defined the switch type to be basic-ni. If this h..

Using MSDP to Discover External Sources

The typical way to configure Multicast Source Discovery Protocol (MSDP) involves first selecting one of your MBGP routers as the RP for your internal network. Then you set up an MSDP peer relationship with the RP in another Autonomous System, which is usually an MBGP peer router in the next domain. The following configuration includes commands required to configure the router as an RP for the internal network using BSR: Router-ASBR1#configure terminal Enter configuration c..