IPv4 Multicast Layer 3 Switching Overview
The Policy Feature Card (PFC) provides Layer 3 switching for IP multicast flows using the hardware replication table and hardware Cisco Express Forwarding (CEF), which uses the forwarding information base (FIB) and the adjacency table on the PFC. In systems with Distributed Forwarding Cards (DFCs), IP multicast flows are Layer 3 switched locally using Multicast Distributed Hardware Switching (MDHS). MDHS uses local hardware CEF and replication tables on each DFC to perform La..
As mentioned earlier, computers cannot use the familiar base 10 numbering system. Computers are essentially constructed using millions of devices that can have only two positions—on or off. It is logical to represent the value of a switch by the symbols 0 and 1 representing off and on. This is called the base 2 or binary numbering system. Base 2 means there are only two symbols as opposed to the base 10 numbering system that has ten symbols. In the base 10 system, you work ..
This pair of router configurations shows how to define a tunnel connecting two serial ports supporting Bisync (BSC or Binary Synchronous Communications) devices: BSTUN-A#configure terminal Enter configuration commands, one per line. End with CNTL/Z. BSTUN-A(config)#interface Loopback0 BSTUN-A(config-if)#ip address 10.1.16.5 255.255.255.252 BSTUN-A(config-if)#exit BSTUN-A(config)#bstun peer-name 10.1.16.5 BSTUN-A(config)#bstun protocol-group 1 bsc BSTUN-A(config)#interf..
PPP over Frame Relay Frame Format
RFC 1973 (PPP in Frame Relay) defines a Frame Relay frame format to encapsulate a PPP encapsulated packet in a Frame Relay frame. Based on RFC 1973, PPP uses Frame Relay as a framing mechanism. The Frame Relay frame format outlined in RFC 1973 closely resembles the Frame Relay frame format defined in RFC 1490 and RFC 2427 (Multiprotocol Interconnect over Frame Relay). Figure 10-3 shows a close comparison between the RFC 1973 PPP over Frame Relay frame format and the RFC 1490/..
The static routes that we discussed in the previous section all had relatively low administrative distance values. If the router has two routes to the same destination but with different distances, it will always choose the one with the lower distance value. This concept also includes the routes that come from other sources, such as dynamic routing protocols. Every routing protocol has an administrative distance that indicates how much the router trusts the information it rec..
