Hi Mark,

On Mon, 6 Apr 2020 at 18:51, Mark Tinka <mark.tinka@seacom.mu> wrote:
>
> However, VMware ESXi does not
> support anything larger than 9,000 bytes, and that is where we run our RR's.

Since vsphere67u3 (ESXi 6.7 U3), you can set an MTU of up to 9,190 bytes:

[root@esxi01o:~] esxcli network vswitch standard list
vSwitch2
   Name: vSwitch2
   Class: cswitch
   Num Ports: 3456
   Used Ports: 1
   Configured Ports: 128
   MTU: 9000
   CDP Status: listen
   Beacon Enabled: false
   Beacon Interval: 1
   Beacon Threshold: 3
   Beacon Required By:
   Uplinks:
   Portgroups: pg-vlan204-LAB-STORAGE, pg-trunk, pg-vlan201-LAB-VMGMT

[root@esxi01o:~] esxcli network vswitch standard set -m=9190 -v vSwitch2
[root@esxi01o:~] esxcli network vswitch standard list
vSwitch2
   Name: vSwitch2
   Class: cswitch
   Num Ports: 3456
   Used Ports: 1
   Configured Ports: 128
   MTU: 9190
   CDP Status: listen
   Beacon Enabled: false
   Beacon Interval: 1
   Beacon Threshold: 3
   Beacon Required By:
   Uplinks:
   Portgroups: pg-vlan204-LAB-STORAGE, pg-trunk, pg-vlan201-LAB-VMGMT

The host UI doesn't let you go >9000 bytes so (for now) you need to use the CLI.

Are your FRR VM vNICs attached to standard or distributed vswitch port groups?

You'll also need >9,000 byte MTU support in the vNIC driver, obviously.

Cheers,
Dale