SHARIFUL's TECH BLOG

In our previous blog post -  Stacking switches Part - V (Cisco Nexus vPC - Virtual Port Channel) , we have looked at how to configure vPC between two nexus switches. But we were at a huge disadvantage - because of the underlying architecture how vPC/MLAG works. With any MLAG implementation, we are still managing two individual switches, they are just facilitating a LACP aggregation link which is spread throughout the vPC peers. And we are configuring the same things twice - one time in each peer of our vPC domain. There is always risk in such setup that we miss some configuration commands in one of the switch and the vPC interfaces does not comes up. Cisco has implemented a feature called switch-profile which allows configuration syncing to all the vPC peer switches. We just configure a profile in both peer switches, make our configuration changes, then NX-OS validates the configuration and pushes it throughout the vPC domain. The good thing with config-sync is that it ...

Now it is time to adress the configuration of most popular  MLAG (multi chassis link aggregation)  out there - Cisco Nexus Switches running NX-OS. I will not go in detail about Nexus series of switches as everybody knows about them. Instead let's just jump into how to configure vPC in nexus switches. Just one this Cisco calls their implementation of MLAG - vPC (virtual port channel) . Let's look at our network topology -  Two Cisco Nexus switches will run peering between them and will form vPC/MLAG. Two Debian 10 linux machine will form multichassis link-aggregation with Nexus switches. They will simulate the client connection. Our topology looks like below - Cisco Nexus vPC Topology Let's look at some terminology before configuration - vPC peer-link - Link used to synchronize the state between vPC peer devices. In the topology, po256 interface containing eth1/6-7 interfaces is the peer-link. vPC peer-keepalive link - The keepal...