Add middleware support for setting/unsetting bridge member's flags
Copying to see if anything needs to be done for UI
Currently (to my knowledge, I may be wrong) py-netif does not support setting/unsetting flags to bridge members, e.g.
bridge0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500 ether 02:98:e1:04:1a:00 nd6 options=9<PERFORMNUD,IFDISABLED> groups: bridge id 00:00:00:00:00:00 priority 32768 hellotime 2 fwddelay 15 maxage 20 holdcnt 6 proto rstp maxaddr 2000 timeout 1200 root id 00:00:00:00:00:00 priority 32768 ifcost 0 port 0 member: em0 flags=1c3<LEARNING,DISCOVER,AUTOEDGE,PTP,AUTOPTP> ifmaxaddr 0 port 1 priority 128 path cost 20000
We cant disable DISCOVER for em0, neither enable STP.
We need to support it in py-netif for future use from middlewared.