TKIP

The 802.11i working group has improved the security of 802.11 wireless LANs with an update to the 802.11 standard in 2004. The Temporal Key Integrity Protocol, for example, fixes the keyreuse problem of WEP. The TKIP process begins with a 128-bit “temporal key” shared among clients and access points. TKIP combines the temporal key with the client’s MAC address and then adds a relatively large 16-octet initialization vector to produce the key used to encrypt data. This..

Routing Policy and the Routing Arbiter Service

Remember that NSFNET has been using a Policy Routing DataBase (PRDB) since 1989, both to prevent routing loops when EGP was used between the backbone and the regionals, and to ensure that each regional announced correct routing information. (Incorrect information could be announced simply due to configuration errors in the regional networks.) When it was introduced, BGP made loop detection easy by virtue of its path attribute. If an AS appears in the path twice, the route i..

Finding an IP Route

The EXEC level command to look at the entire IP routing table is: Router>show ip routeCodes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2       E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP    ..

Configuring an IOS DHCP Server

After you have configured a Layer 3 address on a switch interface, you can configure a DHCP server that runs natively on the switch itself. The switch will intercept DHCP broadcast packets from client machines within a VLAN. Use the following command sequence to configure a DHCP server: Switch(config)# ip dhcp excluded-address start-ip end-ip Switch(config)# ip dhcp pool pool-name Switch(config-dhcp)# network ip-address subnet-mask Switch(config-dhcp)# default-router ip-addr..

Filtering Routes with RIP

The access list in the first configuration example of this recipe prevents this router from accepting any routing information about the network 192.168.20.0: Router2(config)#access-list 10 deny 192.168.20.0 Router2(config)#access-list 10 permit any You can see that this route , no longer appears in the routing table: Router2#show ip route rip R    172.22.0.0/16 [120/1] via 172.25.2.1, 00:00:21, Serial0.1 R    172.25.1.0/24 [120/1] via 172.25.2...