IS-IS is similar to OSPF; it uses the default-information originate router subcommand. In the configuration for RTA in Example 12-59, RTA originates a default into IS-IS only on the condition that RTA learns the default from its exterior link. Example 12-59. Using IS-IS as the IGP: RTA Configuration router isis 100 redistribute connected default-information originate route-map SEND_DEFAULT_IF net 49.0001.0000.0c00.000a.00 router bgp 3 no synchronization network 172.16.220.0..
Enhanced IGRP is an interior gateway routing protocol designed for various networks and media. Enhanced IGRP is an advanced distance-vector protocol. The underlying concepts are the same as those of distance-vector protocols, except that Enhanced IGRP is a non-periodic incremental protocol. This differs from traditional distance-vector protocols, in which complete routing updates are sent periodically, using unnecessary bandwidth and CPU resources. Improvements to Enhanced ..
Providing Notifications for Network Events
Whereas responding to problem reports from users is a reactive form of troubleshooting, monitoring network devices for significant events and responding to those events is a proactive form of troubleshooting. For example, before a user loses connectivity with the Internet, a router that is dual-homed to the Internet might report the event of one of its Internet connections going down. The redundant link can then be repaired, in response to the notification, thus resolving the..
Frame Relay End-to-End Keepalive Feature Defined
The Frame Relay End-to-End Keepalive feature is a Cisco proprietary protocol and is supported only on Cisco devices. It is an extension of the Frame Relay LMI protocol, and it runs over the data channels (DLCI) instead of the reserved DLCI used by the LMI protocols. The Frame Relay End-to-End Keepalive feature is configured in a Frame Relay map class and is supported on a per-PVC basis. NOTE The encapsulation method for Frame Relay End-to-End Keepalive packets is proprietar..
The Inter-Switch Link (ISL) protocol is a Cisco-proprietary method for preserving the source VLAN identification of frames passing over a trunk link. ISL performs frame identification in Layer 2 by encapsulating each frame between a header and a trailer. Any Cisco switch or router device configured for ISL can process and understand the ISL VLAN information. ISL primarily is used for Ethernet media, although Cisco has included provisions to carry Token Ring, FDDI, and ATM fra..
