Nexus 5548P - FEX 2248 VPC question

[magnus.pettersson]

Hi, I have two questions

In a straight-through topology, is it possible to connect a windows 2008 fileserver with dual nic and configure VPC? (see attached picture)

In a straight-through topology, do I need to create the same FEX number on each N5K in order to use config-sync?

Cheers

Magnus

[mcusine]

Hi Magnus,

Yes, you can.

You need to create different FEX for each 2248, I attach a guide.

The scenari name it's :

Single Homed Fabric Extender vPC Topology

You can connect a server with dual interfaces that are configured in a vPC to a pair of Cisco Nexus 2000

Series Fabric Extenders that you then connect single homed to the Cisco Nexus 5000 Series switches. The

topology that is shown in the following figure provides the vPC functionality to dual homed servers with

1-Gigabit Ethernet uplink interfaces.

Plase rate is it help.

Regards,

Mauricio

[magnus.pettersson]

If I configure FEX100 and FEX120

Are you sure Config-sync will work?

If I configure ethernet 100/1/1.......and the issues configure sync, the other nexus will not understand ethernet 100/1/1 as it does not have that interface (the other N5k will have ethernet 120/1/1)

Sincerely

Magnus

[mcusine]

Hi Magnus,

The config sync in the Nexus is a litle bit extrange. You have a connection between the Nexus 5K but you have straigtrough topology, each N2K it's only conneted to one 5K.

The config will not syncronize because you have only one conexion in the 2K to the 5K but the VPC will work.

Check the link I sent you, you have a valid topology.

Regards,

Mauricio

[spaladug]

Hi Magnus,

You are correct that you need to have identical FEX numbers on both Nexus 5ks. Otherwise config sync will not work since you do not have FEX interfaces that began with the same number. It does not matter if you are using single homed or dual homed FEXs. You just need to have the same FEX numbers on both sides. Think of "config sync" mode just like you think of "config t" mode, but that the switch will in the background go to the other switch and type in the exact same commands into the configuration.