Description of problem:

shutdown a host with bridged network wont disconnet it's ssh session

Version-Release number of selected component (if applicable):
systemd-sysv-207-8.el7.x86_64
systemd-libs-207-8.el7.x86_64
systemd-207-8.el7.x86_64
libgudev1-207-8.el7.x86_64
initscripts-9.49.11-1.el7.x86_64

How reproducible:
100%

Steps to Reproduce:
define a bridge
1.[root@dhcp-8-232 network-scripts]# cat ifcfg-enp1s0f0 
# Generated by dracut initrd
DEVICE=enp1s0f0
ONBOOT=yes
NETBOOT=yes
HWADDR="00:15:17:3a:42:74"
TYPE=Ethernet
BRIDGE=switch
[root@dhcp-8-232 network-scripts]# cat ifcfg-switch 
DEVICE=switch
BOOTPROTO=dhcp
ONBOOT=yes
DELAY=0
TYPE=Bridge
[root@dhcp-8-232 network-scripts]# 

2.reboot the host to make the host boot w/ bridged network
and confirm bridge working
# brctl show switch
bridge name	bridge id		STP enabled	interfaces
switch		8000.0015173a4274	no		enp1s0f0

3. login via ssh, then send 'reboot'

Actual results:
the ssh session wont disconnected automatically

Expected results:
ssh session disconnected

Additional info:

This is a Regression introduced since systemd-207-1.el7
Tried systemd-206-8.el7 working fine.
# rpm -qa | grep -i 206-
systemd-sysv-206-8.el7.x86_64
systemd-libs-206-8.el7.x86_64
systemd-206-8.el7.x86_64
libgudev1-206-8.el7.x86_64