No network connectivity in KVM guest

I'm attempting to set up my first guest set up under KVM and am having trouble getting the network working.

The host machine "vm_host_box" has a static IP of 4.4.4.185.
The guest I am setting up needs to have a static IP of 4.4.4.200.

I currently have zero connectivity to anything (including gateway) from the guest VM. Note that the guest VM is a minimal install and I'm not able to install any additional packages due to not having network for yum.

Here's what I can see from the host:

[root@vm_host_box ~]# cat /etc/sysconfig/network-scripts/ifcfg-em1 
TYPE=Ethernet
BOOTPROTO=none
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
NAME=em1
UUID=some-string-here
DEVICE=em1
ONBOOT=yes
DNS1=4.4.10.1
DOMAIN=vmhostbox.my.domain
IPV6INIT=no
IPADDR=4.4.4.185
PREFIX=23
GATEWAY=4.4.4.2

list of other ifcfg-* files:

[root@vm_host_box network-scripts]# ls ifcfg-*
ifcfg-em1  ifcfg-em2  ifcfg-em3  ifcfg-em4  ifcfg-lo

ip addr details:

[root@vm_host_box ~]# ip addr show em1
2: em1: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN qlen 1000
    link/ether 14:18:77:69:b6:9a brd ff:ff:ff:ff:ff:ff
    inet 4.4.4.185/23 brd 170.140.203.255 scope global em1
       valid_lft forever preferred_lft forever

[root@vm_host_box ~]# ip addr show virbr0
6: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN qlen 1000
    link/ether 52:54:00:11:3f:7e brd ff:ff:ff:ff:ff:ff
    inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0
       valid_lft forever preferred_lft forever

brctl shows a bridge, but there is an interface listed and I'm not sure how it was added.

[root@vm_host_box ~]# brctl show
bridge name bridge id       STP enabled interfaces
virbr0      8000.525400113f7e   yes     virbr0-nic

Here's the virsh details for the default network. I'm unclear about the range of IPs. Will virsh be creating a new subnet, or am I telling it what IP's to look out for?

[root@vm_host_box ~]# virsh net-list --all
 Name                 State      Autostart     Persistent
----------------------------------------------------------
 default              active     yes           yes



[root@vm_host_box ~]# virsh net-edit default

<network>
  <name>default</name>
  <uuid>0b06b7c0-708f-4925-a8f6-84587bf96575</uuid>
  <forward mode='nat'/>
  <bridge name='virbr0' stp='on' delay='0'/>
  <mac address='52:54:00:11:3f:7e'/>
  <ip address='192.168.122.1' netmask='255.255.255.0'>
    <dhcp>
      <range start='192.168.122.2' end='192.168.122.254'/>
    </dhcp>
  </ip>
</network>

Here's what I am showing under KVM's Connection Details screens:

and

Here is the config after starting the Guest (labeled "rhel7")

Any pointers would be greatly appreciated.