In Figure 5.13, another router has been added to the internetwork with a subnet 10.33.32.0/20 on its E1 interface. The problem is that the other subnet of network 10.0.0.0, 10.33.0.0/20, is connected to Barney, and the only route between the subnets is via 192.168.83.0 and 192.168.12.0—two entirely different networks. As a result, network 10.0.0.0 is discontiguous. Figure 5.13. Classful protocols such as RIP and IGRP cannot route a topology in which the subnet..
The VLAN Trunking Protocol developed by Cisco operates as a Layer 2 protocol for Catalyst products. When transmitting VTP messages to other Catalysts in a network, a Catalyst encapsulates the VTP message in a trunking protocol frame, such as ISL or 802.1Q. Figure 12-5 shows the generic encapsulation for VTP within an ISL frame. The ISL encapsulation starts with the header information detailed in Chapter 8, "Trunking Technologies and Applications." The VTP header varies depend..
Data Structures of IP Routing Protocols
As traffic is routed through a network, the routers encountered along the way from the source to the destination need consistency in how they route traffic. For example, if one router selected the best path based on hop count, and another router selected the best path based on a link’s bandwidth, a routing loop could conceivably occur. Fortunately, having a common routing protocol configured on all routers within a topology helps ensure consistency in routing decisions. T..
Enabling and Disabling NTP Per Interface
Depending on the level of access control required, you can use the ntp disable command to prevent the router from providing NTP services on a particular interface: Router#configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)#interface Serial0/1 Router(config-if)#ntp disable Router(config-if)#end Router# You can also prevent the router from providing NTP services on an individual interface with access control lists: Router#con..
Two versions of VTP are available for use in a management domain. Catalyst switches are capable of running either VTP version 1 or VTP version 2. Within a management domain, the two versions are not interoperable. Therefore, the same VTP version must be configured on every switch in a domain. VTP version 1 is the default protocol on a switch. If a switch is capable of running VTP version 2, however, a switch can coexist with other version 1 switches, as long as its VTP versio..
