OSPFv3 also differs from OSPFv2 in many ways. The most obvious is that OSPFv3 supports 128-bit prefixes. OSPFv3 runs directly within IPv6 packets and can co-exist with OSPFv2. The two routing protocols do not exchange information or pay attention to each other in any way (this is referred to as "ships in the night" routing in some documentation, because packets from the two versions of OSPF pass each other without knowing of the other's existence, like ships passing in ..
Several DiffServ RFCs suggest a set of values to use in the DSCP field and an implied meaning for those settings. For instance, RFC 2598 defines a DSCP of decimal 46, with a name Expedited Forwarding (EF). According to that RFC, packets marked as EF should be given queuing preference so that they experience minimal latency, but the packets should be policed to prevent them from taking over a link and preventing any other types of traffic from exiting an interface during perio..
Establishing Adjacencies on a Point-to-Point Link
When point-to-point links are used, adjacency occurs after a Hello packet has been received. Next, each side sends a CSNP. The CSNP is a list of all the links held in the linkstate database, which triggers a synchronization of the link-state database on each machine. Periodic Hellos maintain the adjacency. If a router does not hear a Hello within the Hello holdtime, the neighbor is declared dead and the database is purged of any entries associated with the router. Cisc..
Unequal-Cost Load Balancing in IGRP
IGRP and RIP provide the capability to install up to six parallel equal-cost paths for load balancing. IGRP has an added feature that RIP does not have—the capability to do unequal-cost load balancing, the capability to load-balance traffic over multiple paths that do not have the same metric to the destination. The advantage of this feature is that it offers the flexibility of load balancing, thus making more efficient use of the link. IGRP uses the variance command to per..
Stateful NAT allows you to combine NAT functionality with HSRP using two routers in a high availability configuration: Router-A#configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router-A(config)#access-list 11 permit any Router-A(config)#ip nat pool NATPOOL 172.17.100.100 172.17.100.150 netmask 255.255.255.0 Router-A(config)#ip nat inside source list 11 pool NATPOOL mapping-id 1 Router-A(config)#interface FastEthernet0/0 Router-A(con..
