Configuring Bandwidth over a Hybrid Multipoint Network

If the multipoint network has differing speeds allocated to the VCs, a more complex solution is needed. There are two main approaches:  • Take the lowest CIR and multiply it by the number of circuits. Apply the product as the bandwidth of the physical interface. The problem with this configuration is that EIGRP will underutilize the higher-bandwidth links.  • If possible, it is much easier to configure and manage an environment that has used subinterfaces, whe..

Disabling Link Up/Down Traps per Interface

To disable SNMP link-status change traps for a particular interface, use the following configuration command: Router#configure terminal Enter configuration commands, one per line.  End with CNTL/Z. Router(config)#interface Serial0/0 Router(config-if)#no snmp trap link-status Router(config-if)#exit Router(config)#end Router# By default, the router forwards SNMP link up or down traps whenever an interface changes states. Normally, you want to receive traps when an inter..

Troubleshooting VTP

 If a switch does not seem to be receiving updated information from a VTP server, consider these possible causes: ■ The switch is configured for VTP transparent mode. In this mode, incoming VTP advertisements are not processed; they are relayed only to other switches in the domain. ■ If the switch is configured as a VTP client, there might not be another switch functioning as a VTP server. In this case, configure the local switch to become a VTP server itself. ■ T..

Controlling Multicast Scope with Administratively Scoped Addressing

To configure regions of multicast scope using addressing rather than TTL, using the ip multicast boundary interface command: Router1#configure terminal Enter configuration commands, one per line.  End with CNTL/Z. Router1(config)#ip multicast-routing Router1(config)#access-list 15 deny 239.255.0.0 0.0.255.255 Router1(config)#access-list 15 permit any Router1(config)#interface FastEthernet0/0 Router1(config-if)#ip multicast boundary 15 Router1(config-if)#end Rout..

Filtering Based on TCP Header Flags

The following ACL blocks several illegal combinations of TCP header flags: Router1#configure terminalEnter configuration commands, one per line.  End with CNTL/Z.Router1(config)#access-list 161 deny tcp any any ack fin psh rst syn urgRouter1(config)#access-list 161 deny tcp any any rst syn Router1(config)#access-list 161 deny tcp any any rst syn finRouter1(config)#access-list 161 deny tcp any any rst syn fin ackRouter1(config)#access-list 161 deny tcp any any syn fin Rou..