Multicast The IP communication traditionally defines the unicast communication, when there is a host to host communication, or 1:1, and the broadcast type of communication where one host sends to all other hosts. When there is the need to communicate with multiple, but not all, hosts the broadcast communication is not effective as all hosts […]

Note No license is required for BFD features. BFD has the following configuration limitations: NX-OS supports BFD version 1. BFD supports single-hop BFD; BFD for BGP supports single-hop EBGP and iBGP peers. BFD depends on Layer 3 adjacency information to discover topology changes, including Layer 2 topology changes. A BFD session on a VLAN interface […]

Bidirectional Forwarding Detection Bidirectional Forwarding Detection (BFD) is a detection protocol designed to provide fast forwarding–path failure detection times for media types, encapsulations, topologies, and routing protocols. BFD provides subsecond failure detection between two adjacent devices and can be less CPU-intensive than protocol hello messages because some of the BFD load can be distributed onto […]

Example 1-10 shows SW9621-1 BGP feature enabling and BGP router configurations. Example 1-10 BGP AS 65100 Creation Configuration SW9621-1(config)#feature bgpSW9621-1(config)#router bgp 65100SW9621-1(config-router)#router-id 1.1.1.1SW9621-1(config-router)#address-family ipv4 unicastSW9621-1(config-router-af)#network 192.168.1.0/24SW9621-1(config-router)#neighbor 2201:db1::2 remote-as 65100SW9621-1(config-router-neighbor)#address-family ipv6 unicastSW9621-1(config-router)#neighbor 10.10.10.2 remote-as 65100SW9621-1(config-router-neighbor)#address-family ipv4 unicastSW9621-1(config-router-neighbor)#address-family ipv4 multicastSW9621-1(config-router)#neighbor 10.10.10.6 remote-as 100SW9621-1(config-router-neighbor)#address-family ipv4 unicast Example 1-11 shows SW9621-1 interface configurations. Example 1-11 Interface Configurations SW9621-1(config)#interface loopback1SW9621-1(config-if)#ip address 192.168.1.1/24SW9621-1(config)#interface […]

Note The order of comparison determined in Step 2 is important. Consider the case where you have three paths—A, B, and C. When Cisco NX-OS compares A and B, it chooses A. When Cisco NX-OS compares B and C, it chooses B. But when Cisco NX-OS compares A and C, it might not choose A […]

Note If Cisco NX-OS receives no MED attribute with the path, Cisco NX-OS considers the MED to be 0 unless you configure the best-path algorithm to set a missing MED to the highest possible value. e. If the nondeterministic MED comparison feature is enabled, the best-path algorithm uses the Cisco IOS style of MED comparison. […]

Note The dynamic AS number prefix peer configuration overrides the individual AS number configuration that is inherited from a BGP template. To establish BGP sessions between peers, BGP must have a router ID, which is sent to BGP peers in the OPEN message when a BGP session is established. The BGP router ID is a […]

Border Gateway Protocol Border Gateway Protocl (BGP) provides loop-free routing between different autonomous systems or organizations, or domains. It uses a path-vector routing algorithm to exchange routing information between BGP speakers. Based on this information, each BGP speaker determines a path to reach a particular destination while detecting and avoiding paths with routing loops. The […]

Example 1-6 OSFPv3 ABR Verification (SW9621-1) SW9621-1#show ospfv3 neighbors OSPFv3 Process ID 23 VRF default Total number of neighbors: 1 Neighbor ID Pri State Up Time Interface ID Interface 1.1.1.15 1 FULL/DR 00:00:54 36 Eth2/3 Neighbor address fe80::200:ff:feff:1ff OSPFv3 Process ID 21 VRF default Total number of neighbors: 1 Neighbor ID Pri State Up Time […]

Note Use the ip ospf mtu-ignore command for OSPFv2 or ipv6 ospf mtu-ignore command for OSPFv3 to disable MTU mismatch detection on an interface. By default, OSPF checks whether neighbors use the same MTU on a common interface. If the receiving MTU is higher than the IP MTU configured on the incoming interface, OSPF does […]