ith the configured vPCs: NX-5K-1(config-if)# vpc domain 1 vPCs require a link between the vPC peer switches, called a peer keepalive link. This link is in addition to the port channel between the switches in which the VLAN trunks ride. The peer keepalive link must be a routed link, in that an IP address is used on each side. The link can be over an existing IP network, but Cisco suggests that it be Chapter 7: Link Aggregation established over the management interface. This is especially important on the Nexus 5000s, since there are no Layer-3 interfaces except for the management interface. I'm not a huge fan of putting what amounts to critical (criticality is in the eye of the be- holder) connections on the management network, but this example shows how to do SO. The management VRF is used by default on the 5000 (see Chapter 18 for more information regarding VRFs): NX-5K-1 (config-vpc)# peer-keepalive destination 10.10.10.2 On a Nexus 7000, this link can be any interface, since they all default to routing mode anyway. Here is the configuration for a point-to-point link between two Nexus 7000s. First we configure NX-7K-1: NX-7K-1(config-if-range)# int e3/1 (-7K-1(config-if)# ip address 10.255.255.1/24 NX-7K-1 (config-vpc-domain)# peer-keepalive destination 10.255.255.2 And now the other switch, named NX-7K-2: X-7K-2(config-if-range)# int e3/1 NX-7K-2(config-if)# ip address 10.255.255.2/24 NX-7K-2 (config-vpc-domain)# peer-keepalive destination 10.255.255.1 vPC requires that a link-preferably a trunk-between the vPC peers be defined as a peer link. This link will be used for the traversal of traffic necessary to utilize the ether channel. Generally, this link is the main interswitch link between the two switches. The vPC peer link must be a multi-10 G bps EtherChannel according to the documentation, but of course it will work with only one physical link. This command is the same on both the 5000 and the 7000. Here, port channel 1 is used as the peer link: NX-5K-1 (config-if)# int po 1 5K-1(config-if)# vpc peer-link