BGP Messages and Neighbor States
The desired state for BGP neighbors is the established state. In that state, the routers have formed a TCP connection, and they have exchanged Open messages, with the parameter checks having passed. At this point, topology information can be exchanged using Update messages. Table 12-3 lists the BGP neighbor states, along with some of their characteristics. Note that if the IP addresses mismatch, the neighbors settle into an active state. Table 12-3 BGP Neighbor States
802.11 shared key authentication goes a step further than open system authentication by using the common WEP key to authenticate radio cards. This is a four-way handshaking process: 1. The radio card sends an authentication request. 2. The access point responds with an authentication frame containing challenge text, which is a string of unencrypted text. 3. The radio card encrypts the challenge text with the WEP key and sends the result to the access point. 4. The access ..
Multiplexing is a fundamental element of network design. Indeed, you could argue that a network is typically one huge multiplexing system. More specifically, however, multiplexing is a tool that provides economies of scale—multiple users share one large resource rather than a number of individual resources. NOTE Multiplexing is the aggregation of multiple independent traffic flows into one large traffic flow. A useful analogy is the freeway system, which mul..
HSRP election is based on a priority value (0 to 255) that is configured on each router in the group. By default, the priority is 100. The router with the highest priority value (255 is highest) becomes the active router for the group. If all router priorities are equal or set to the default value, the router with the highest IP address on the HSRP interface becomes the active router. To set the priority, use the following interface configuration command: Switch(config-if)# ..
The precise output of the show ip protocols command varies, depending on what features are enabled. However, we have shown several examples of different output throughout this chapter: Router1#show ip protocols Routing Protocol is "eigrp 55" Outgoing update filter list for all interfaces is not set Incoming update filter list for all interfaces is not set Serial0.1 filtered by (prefix-list) Inbound Default networks flagged in outgoing upda..
