Persistent epair interface in jail?

[digilink]

I'm running a FreeNAS Mini appliance and have both network cards on different networks. I created a jail to host DNS and DHCP for the network located on igb0.

The problem I seem to have encountered is that the interface changes on a reboot and kills my dhcpd daemon (I'm using ISC-dhcpd) due to it listening on a specific interface defined in /etc/rc.conf:

Code:

dhcpd_enable="YES"                          
dhcpd_flags="-q"                            
dhcpd_conf="/usr/local/etc/dhcpd.conf"      
dhcpd_ifaces="epair0b"                      
dhcpd_withumask="022"            

Is there a way to make this interface persistent across reboots?

 

[Nick2253]

What interface is changing on reboots? The jail interface? And what about it is changing? Mac address? IP address?

 

[digilink]

Looks to be the jail interface itself. For example, when I first built out the jail, the interface assigned was epair1b (if I remember correctly, it was different than what it is now anyhow). I rebooted the FreeNAS server and that's when I discovered it had changed to the current interface of epair0b.

This is the output of my ifconfig (from the jail):

Code:

sbrown@delorean:~ % ifconfig
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0 mtu 16384
        options=600003<RXCSUM,TXCSUM,RXCSUM_IPV6,TXCSUM_IPV6>
        inet6 ::1 prefixlen 128 
        inet6 fe80::1%lo0 prefixlen 64 scopeid 0x1 
        inet 127.0.0.1 netmask 0xff000000 
        nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
epair0b: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        options=8<VLAN_MTU>
        ether 02:7a:f4:00:0e:0b
        inet 10.0.10.25 netmask 0xffffff00 broadcast 10.0.10.255
        nd6 options=9<PERFORMNUD,IFDISABLED>
        media: Ethernet 10Gbase-T (10Gbase-T <full-duplex>)
        status: active

 

[Nick2253]

Now, that is weird. If you reboot again, does it change again? Or does it only change sporadically?

 

[digilink]

Just rebooted again, it's still epair0b, so maybe something was just flakey. I was mainly concerned if this was a natural behavior or not, and was going to set it accordingly to compensate if so.