Private Link Used as Primary Between AS2 and AS3
Figure 7-19 illustrates a case in which the link between AS2 and AS3 is used as a primarylink for all traffic to AS3's local networks or to AS3's customers. For all other traffic, the linkto the provider AS1 should be used. The two links (provider and private) should back up oneanother. Figure 7-19. Private Links Used as Primary AS Interconnection Assume that the environment illustrated in Figure 7-19 features default, full, and partialrouting; the following discussio..
802.11 Wired Equivalent Privacy uses a common key to encrypt and decrypt data frame contents between 802.11 stations at Layer 2. 802.11, however, does not define a mechanism for distributing WEP keys to the stations. This requires the administrator or users to manually configure their radio cards with the encryption key, and it is not practical to change the key. Thus, WEP keys remain the same on most wireless LANs for months or years. This allows enough time for a hacker to ..
Integrated Services Digital Network (ISDN) is used by telephone companies to carry digitized voice and data over the existing telephone system. ISDN has emerged as one of the leading technologies for telecommuting and remote office connection into the corporate headquarters. On the seven layer model, ISDN operates at the physical, data link, and network layers. ISDN basic rate interface (BRI) provides two barrier channels (commonly referred as B channels). Each of these B ch..
Manually Configuring STP Timers
Use one or more of the following global configuration commands to modify STP timers: Switch(config)# spanning-tree [vlan vlan-id] hello-time seconds Switch(config)# spanning-tree [vlan vlan-id] forward-time seconds Switch(config)# spanning-tree [vlan vlan-id] max-age seconds Notice that the timers can be changed for a single instance (VLAN) of STP on the switch by using the vlan vlan-id parameters. If you omit the vlan keyword, the timer values are configured for all in..
The following commands configure EIGRP on one router in a simple network: Router1#configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router1(config)#interface Ethernet0 Router1(config-if)#ip address 192.168.20.1 255.255.255.0 Router1(config-if)#exit Router1(config)#interface Serial0.1 point-to-point Router1(config-subif)#ip address 172.25.2.2 255.255.255.252 Router1(config-subif)#exit Router1(config)#router eigrp 55 Router1(config-router)#n..
