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Laz Peterson

"IP passthrough" for cellular/dialer connection

Hello there community,

I really don't know how to approach this, but I am trying to achieve an "IP passthrough" type of functionality from our 2901 with EHWIC-4G-LTE-V to our 7201.

Our Verizon account has a single static IP, and we have no problems setting up the dialer, connecting, or using the 2901+LTE for inside clients to reach the internet.

Since we have many VPN connections and no hardware encryption on the 2901, we want to use our 7201 with SA-VAM2+ for all of the communications, but the 2901 simply for its ability to use the LTE.  (When using the 2901 for our VPN connections, the CPU is so burdened that it very seriously affects the networking performance, even just LAN to router.)

The functionality we are trying to achieve would be similar to a CradlePoint that connects to the Verizon network, and then hands the static IP address over using DHCP.  In one of our locations, we have it setup this way.  Let's say the static IP is "", then the result is a DHCP lease on the non-CradlePoint router at with a subnet mask of and gateway of

I have tried setting up a transparent bridge, but the only documentation I can find is for PPPoE connections.  And nothing I have tried works.  All I want to do is pass our external static IP through the 2901 on to the 7201 router, and give it the static IP on one of its Ethernet interfaces so that it can maintain all of the VPN and failover routes.

Is this even possible?  If so, what type of configuration should I be looking at?

I have tried all sorts of bridge configurations with "bridge irb" and "no ip routing", while also setting "bridge 1 route ip" and setting "no dialer-list 1 protocol ip permit" with "dialer-list 1 protocol bridge permit", but also "dialer-list 1 protocol ip permit" and "dialer-list 1 protocol bridge permit".  And adding Dialer0 and GigabitEthernet0/0 to the bridge group.  Needless to say, I'm a little lost -- but would like to know whether or not this is even possible before I invest too much more time into it.

Any help would be greatly appreciated.  Thank you all.

~Laz Peterson