which command to show UTEP/MTEP for the subnet segment

[hongjun]

how do we know which VTEP is selected as local UTEP/MTEP for a particular subnet in unicast/hypbrid/multicast mode?

[rbenhaim · Accepted solution]

esxcli network vswitch dvs vmware vxlan network vtep list --vds-name=Compute_VDS --vxlan-id=5000

[hongjun]

thanks Roie. How about UTEP in unicast mode?

[rbenhaim]

The screenshot came from VMware Lab where the transport zone work in unicast mode.

so i will say very carefully that this command show for both UTEP and MTEP.

but i'm not 100% sure.

[rbudavari]

It will show 'is MTEP' for both unicast and hybrid mode (the code hasn't been updated to display the difference between UTEP/MTEP yet)

[TronAr]

Who is responsible for MTEP election ? Is the procedure documented somewhere ?

[Richard__R]

The Controller is responsible for electing the MTEP but I haven't seen any low level documentation around the election process.

[TronAr]

I've seen conflicting documents, some indicating that the controller is in charge (NSX ICM course) and some pointing to the originating ESXi host (NSX design guide by HP). Also, I was told that the host does the selection, and was trying to get a definitive answer...

[rbenhaim]

Each source ESXi host done the election for UTEP/MTEP per VNI. (NSX ICM 6.0 need to be updated)

You can read more in the NSX-v design guide page: 27-30.

The next question may ask how the the source ESXi host know if the remote UTEP/MTEP is still alive ?

Answer: The controller will do health check to determine if ESXi host fail using TCP connection to netcpa running on each host.

If UTEP/MTEP is fail, NSX controller will remove this esxi host from VTEP table, then this info will be sync to all other ESXI hosts in the control plane. as results new UTEP/MTEP esxi host will selected.

[Richard__R]

Apologies - I was going by the original ICM content on that one too.

[TronAr]

Thanks, I have not seen the paragraph that makes this (my question) evident:

...

this decision is made locally and independently by each ESXi host to ensure that replication duties

even for traffic belonging to the same logical segment can be shared by multiple VTEPs.

The UTEP/MTEP role appears to be reflected in the MTEP table, but the table is synched by the controller, so many hands on that data, it seems