CCNA :) Be a Good Network Administrator

Configuring EIGRP summarization    3.2.2 This page will teach students how to manually configure summary addresses. EIGRP automatically summarizes routes at the classful boundary. This is the boundary where the network address ends, as defined by class-based addressing. This means that even though RTC is connected only to the subnet 2.1.1.0, it will advertise that it is connected to the entire Class A network, 2.0.0.0. In most cases auto summarization is beneficial because it keeps routing tables as compact as possible. However, automatic summarization may not be the preferred option in certain instances. For example, if there are discontiguous subnetworks auto-summarization must be disabled for routing to work properly. To turn off auto-summarization, use the following command: router(config-router)# no auto-summary With EIGRP, a summary address can be manually configured by configuring a prefix network. Manual summary routes are configured on a per-interf...

Configuring EIGRP 3.2.1 Despite the complexity of DUAL, configuring EIGRP can be relatively simple. EIGRP configuration commands vary depending on the protocol that is to be routed. Some examples of these protocols are IP, IPX, and AppleTalk. This page describes EIGRP configuration for the IP protocol. Perform the following steps to configure EIGRP for IP: Use the following to enable EIGRP and define the autonomous system: router(config)# router eigrp autonomous-system-number The autonomous system number is used to identify all routers that belong within the internetwork. This value must match all routers within the internetwork. Indicate which networks belong to the EIGRP autonomous system on the local router by using the following command: router(config-router)# network network-number The network-number is the network number that determines which interfaces of the router are participating in EIGRP and which networks are advertised by the r...

EIGRP algorithm 3.1.6 This page will describe the DUAL algorithm, which results in the exceptionally fast convergence of EIGRP. The sophisticated DUAL algorithm results in the exceptionally fast convergence of EIGRP. To better understand convergence with DUAL, consider the example in Figure . Each router has constructed a topology table that contains information about how to route to destination Network A. Each topology table identifies the following information: The routing protocol or EIGRP The lowest cost of the route, which is called feasible distance (FD) The cost of the route as advertised by the neighboring router, which is called reported distance (RD) The Topology column identifies the primary route called the successor route (successor), and, where identified, the backup route called the feasible successor (FS). Note that it is not necessary to have an identified feasible successor. The EIGRP network follows a sequence of actions...