Disabling Sync and Using BGP on All Routers in an AS
A second method to overcome the black-hole issue is to simply use BGP to advertise all the BGP learned prefixes to all routers in the AS. Because all routers know the prefixes, sync can be disabled safely. The downside is the introduction of BGP onto all routers, and the addition of iBGP neighbor connections between each pair of routers. (In an AS with N routers, N(N−1)/2 neighbor connections will be required.) With large autonomous systems, BGP performance and convergence ..
EIGRP is designed to work in very large networks. However, EIGRP is design-sensitive. Scaling a network is a major concern in organizations. New demands are constantly driving the networks to use applications that require more bandwidth and less delay; at the same time networks are becoming larger and more complex. Mergers and acquisitions, for instance, do nothing for good design. The factors that can affect the scaling of EIGRP include: • The amount of..
In Figure 20-15, the group traffic that flows over the path from the RP (R3) to R5 to R4 is called a shared distribution tree. It is also called a root-path tree (RPT) because it is rooted at the RP. If the network has multiple sources for the same group, traffic from all the sources would first travel to the RP (as shown with the traffic from host S1 in Figure 20-14), and then travel down this shared RPT to all the receivers. Because all sources in the multicast group use a ..
The Subnet Mask Support field indicates the mask of the route. If this field is 0, the subnet mask is not included for that routing entry. The Subnet Mask field in RIPV2 assists VLSM because every route that is advertised by the RIPV2 routing process carries the actual mask of the route being advertised. This is unlike version 1, in which the router assumes that all the routes with knowledge of the connected network have the same masks as the connected network. RIPV1 does not..
Configuring Ethernet Interface Features
Cisco routers allow you to adjust several different Layer 1 and 2 parameters on Ethernet interfaces, depending on the specific hardware. On interfaces that support more than one medium, you can specify which media type you want to use with the media-type command: Router1#configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router1(config)#interface FastEthernet0/0 Router1(config-if)#media-type 100BaseX Router1(config-if)#duplex full Router1(c..
