Troubleshooting EIGRP Neighbor Relationships

This section discusses methods of troubleshooting issues regarding EIGRP neighbor relationships. The following are the most common causes of problems with EIGRP neighbor relationships: • Unidirectional link • Uncommon subnet, primary, and secondary address mismatch • Mismatched masks • K value mismatches • Mismatched AS numbers • Stuck in active • Layer 2 problem • Access list denying multicast packets • ..

Configuring Dual-Rate Policing

Dual-rate CB Policing requires the same MQC commands, but with slightly different syntax on the police command, as shown here: police {cir cir} [bc conform-burst] {pir pir} [be peak-burst][conform-action action [exceed-action action [violate-action action]]] Note that the syntax of this command requires configuration of both the CIR and a PIR because the curly brackets mean that the parameter is required. The command includes a place to set the Bc value and the Be value as w..

Mitigating the Detrimental Effects of RSVP-TE Restart

As mentioned earlier, RSVP-TE control-plane restart causes detrimental effects on the MPLS forwarding plane. To reduce such harmful effects, the Internet Engineering Task Force (IETF) has defined the RSVP-TE GR restart mechanism.[5] RSVP-TE GR Mechanism RSVP-TE GR allows an LSR to express the following information to its neighbors: •    Its capability to preserve the MPLS forwarding state across its control-plane restart •    Estimated time..

Disabling the Cisco Discovery Protocol

CDP can be an extremely useful feature because it tells you so much information about all of your neighboring devices. However, this can also represent a serious security problem. CDP packets are not encrypted in any way, so if somebody can just capture the CDP packets from a network segment as they pass between the routers, they can easily deduce a lot about your network architecture. And if they can get access to the router either via Telnet or SNMP, they can use the CDP ta..

DHCP-Secured IP Address Assignment

To enable secured IP address assignment, use the update arp command:Router1#configure terminal Enter configuration commands, one per line.  End with CNTL/Z.Router1(config)#ip dhcp pool OREILLYRouter1(dhcp-config)#update arpRouter1(dhcp-config)#endRouter1#Beginning with IOS Version 12.2(15)T, Cisco introduced the concept of DHCP secured IP address assignment. This feature synchronizes the ARP entry to the DHCP binding to ensure that IP addresses assign via DHCP can'..