Comment 5 for bug 1563448

So it looks like restarting the LinuxBridge agent isn't enough to initiate the change. The vxlan interfaces will persist a restart of the service, so they must be deleted first, then a restart of a agent will rebuild them:

Before and after restarting the agent:

293: vxlan-48: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1450 qdisc noqueue master brq41984be8-05 state UNKNOWN mode DEFAULT group default
    link/ether 22:2f:74:e5:51:c3 brd ff:ff:ff:ff:ff:ff promiscuity 1
    vxlan id 48 dev br-vxlan port 32768 61000 proxy ageing 300

After deleting/restarting:

955: vxlan-48: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1450 qdisc noqueue master brq41984be8-05 state UNKNOWN mode DEFAULT group default
    link/ether 52:d9:60:02:f0:fa brd ff:ff:ff:ff:ff:ff promiscuity 1
    vxlan id 48 group 239.1.1.1 dev br-vxlan port 32768 61000 ageing 300

This will, of course, cause downtime for connected instances.