Jail network problems

[chaconc]

After a while, or following a power loss, my jail looses internet connectivity on its own.

I noticed the jail doesn't show in my router's device list, and doing a "ifconfig" from the jail returns the following results:

When network is ok:

Code:

epair0b: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
	options=8<VLAN_MTU>
	ether 02:b7:32:00:07:0b
	inet 172.16.0.199 netmask 0xffffff00 broadcast 172.16.0.255
	inet6 ----::----:----:----:70b%epair0b prefixlen 64 scopeid 0x2 
	nd6 options=3<PERFORMNUD,ACCEPT_RTADV>
	media: Ethernet 10Gbase-T (10Gbase-T <full-duplex>)
	status: active

When network fails:

Code:

epair0b: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
	options=8<VLAN_MTU>
	ether 02:3b:98:00:07:0b
	inet 172.16.0.200 netmask 0xffffff00 broadcast 172.16.0.255
	inet6 ----::----:----:----:70b%epair0b prefixlen 64 scopeid 0x2 
	inet 0.0.0.0 netmask 0xff000000 broadcast 255.255.255.255
	nd6 options=3<PERFORMNUD,ACCEPT_RTADV>
	media: Ethernet 10Gbase-T (10Gbase-T <full-duplex>)
	status: active

There is an extra inet line when it fails. I tried renewing the connection (ifconfig up/down) but it doesn't do anything. Is there any way to let the jail to use DHCP or does anyone have any idea on what could be the problem?