RTEP MTU doesnt change on Edge datapath when Global RTEP config is changed on NSX UI

Products

• VMware NSX

Issue/Introduction

BGP connectivity down between the 2 sites. Tried changing the RTEP Global MTU but it doesn't update MTU on RTEP interface of the edge

Environment

Vmware NSX

Cause

Priority order of mtu: LogicalRouterPortConfig mtu > GlobalConfig mtu > RTEP interface mtu.

So, if LogicalRouterPortConfig has mtu, GlobalConfig mtu change won't get reflected.

During upgrade from some version before 3.2 to 3.2 onwards, GlobalConfig mtu gets copied to LogicalRouterPortConfig mtu.

That's why, after upgrade, GlobalConfig mtu change does not get reflected.

Resolution

Fix is to set LogicalRouterPortConfig mtu to null in upgrade task. Then GlobalConfig mtu change will get reflected. Fixed in all versions 3.2.3 onwards