help: Enable poison reverse for split-horizon
create:vyatta-vtysh -c "configure terminal" -c "interface $IFNAME" \
       -c "ip rip split-horizon poisoned-reverse"

delete:vyatta-vtysh -c "configure terminal" -c "interface $IFNAME" \
       -c "no ip rip split-horizon" -c "ip rip split-horizon "

commit:expression: ($VAR(../disable/) == ""); \
    "You cannot have 'split-horizon poison-reverse' enabled with 'split-horizon' disabled for $IFNAME"