OVS User Bridges are automatically brought up on boot, even if ONBOOT=false in the ifcfg file for the bridge. In order to prevent user bridges from being activated at boot a parameter LINKSTATUS was added in the network-init-scripts to address this use case. Setting LINKSTATUS=down will allow the OVS user bridge to be activated in user space by OVS but not active in kernel space.

In order to fix this issue with OVS User Bridges we need to support configuring LINKSTATUS=down in the user bridge ifcfg files.

With ONBOOT=no only the bridge is activated after boot:
$ ip addr
1: br-link: <BROADCAST,MULTICAST,PROMISC,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UNKNOWN group default qlen 1000
link/ether da:7a:a0:b4:af:48 brd ff:ff:ff:ff:ff:ff
inet6 fe80::d87a:a0ff:feb4:af48/64 scope link
valid_lft forever preferred_lft forever

With the addition of LINKSTATUS=down to the user bridge ifcfg file the bridge is not active in kernel space after boot:
$ ip addr
1. br-link: <BROADCAST,MULTICAST,PROMISC> mtu 1500 qdisc noop state DOWN group default qlen 1000
link/ether da:7a:a0:b4:af:48 brd ff:ff:ff:ff:ff:ff

For reference this is the patch that added the LINKSTATUS parameter to the ifcfg files used by network-init-scripts.