#! /bin/sh

jailName="$1"

# ifconfig returns new epair name as outpout
epairA="$(ifconfig epair create)"
# the second intervace has got b at the end
epairB="${epairA%?}b"

# We rename the interface from the generated name to be te same like jail's name
# The maxium lenght of network interface is about 15 character which souhld be enough
ifconfig $epairA name A$jailName
ifconfig A$jailName up
ifconfig bridge0 addm A$jailName up

ifconfig $epairB name B$jailName
# The line below would only work if called from  exec.created section
#ifconfig eth0 vnet $jailName up
# insipration from https://forums.freebsd.org/threads/jails-vnet-freebsd-mastery-multiple-interfaces.70356/

# to list only epair interfaces you can you can use
# ifconfig -g epair -l