Using Metrics and Metric Types to Influence Redistributed Routes
A different set of issues can occur for a router that is internal to a single routing domain, like R4and R5 in Figure 11-4. The issue is simple—with multiple redistributing routers, an internal routerlearns multiple routes to the same subnet, so it must pick the best route. As covered earlier in thechapter, the redistributing routers can set the metrics; by setting those metrics with meaningfulvalues, the internal routers can be influenced to use a particular redistribution..
The exchange of data in an 802.11 network is bidirectional between the radio card and access point. As mentioned earlier, data frames in an infrastructure wireless LAN do not travel directly between wireless users. Instead, the access point relays the data. A radio card or access point (802.11 station) having the destination MAC address of the data frame replies with an acknowledgement (ACK) frame. This adds significant overhead to a wireless LAN as compared to an Ethernet n..
IPsec Modes of Operation and Security Options
IPsec has many protocol options. This section provides a brief look at the main elements. One concept that's important to understand for IPsec is the concept of security associations, or SAs. An SA is simply a connection that provides security services to the traffic carried by it. When you use IPsec, you build SAs between the communicating devices. The SA contains information about which data traffic is going to be encrypted, how it is encrypted, whether and how it is authen..
Configuring TCP/IP Header Compression over Frame Relay
This section discusses the TCP/IP header compression scheme for Frame Relay virtual circuits. TCP/IP header compression is also commonly known as the Van Jacobson's algorithm, designed and defined in RFC 1144. The TCP/IP header compression scheme relies on the redundant nature of many fields within the TCP/IP headers of a packet after a connection has been established. For the entire duration of the TCP session, the header details for the connection are maintained at both the..
Using Route Maps to Refine Static Translation Rules
One of the best uses of this feature appears when you have two Internet Provider connections and you want to use distinct NAT rules for each: Router1#configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)#interface FastEthernet0/0 Router(config-if)#ip address 172.16.1.5 255.255.255.252 Router(config-if)#ip nat outside Router(config-if)#exit Router(config)#interface FastEthernet0/1 Router(config-if)#ip address 172.16.2.5 25..
