3G with Cisco ASA-5505

ispdude

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Hi

I'm in a bit of a predicament and looking for some help. I'm setting up a Site-to-Site VPN for 7 branches, I have most worked out, but one of the branches is giving me nightmares.

I have head office in Cape Town, ADSL connection. 5 other branches with ADSL connection and one branch with 3G connection (no ADSL available).

I want to install a Cisco ASA-5505 at each site, but I need a public IP on one of the VLANs on each device (i can cope with dynamic as I have a server with a static IP at an 8th branch that won't be part of the VPN, I can set up a DDNS server here - the ASA doesn't support HTTP DDNS services so it would have to be IETF unless there's a company out there that's similar to DynDNS.org but uses IETF protocol, any ideas?). Further I can configure the crypto maps to use hostname lookups.

The problem is that ADSL routers can easily be configured in bridge mode and PPPoE configured on the ASAs, same goes for iBurst, but I've never done this with 3G. That's where I need help, can I get a 3G modem with an ethernet port (instead of the standard PC card or USB) and use PPPoE or some other protocol to bridge it? Otherwise, can I use a 3G router for this and disable the routing? I'm a bit clueless, the ASA-5505 only has Ethernet ports.

As a last resort I can probably use a Cisco 881G, as it can establish a tunnel to a Cisco ASA, but I'd be losing on the security features which I don't want to do.

Regards

ispdude
 
P.S. I have an Option Globesurfer II that's lying around if that can be of any use.
 
Your main thing I guess is you want the ASA to drive the connection on the 3G device. If the ASA doesn't support it then you are left with the following:

1) Apply for the unrestricted APN. This allows unsolicited inbound connections (which I guess you will need)
2) Get a 3G router: Something like the Linksys WRT54G3G (takes a PCMCIA card) or the Vodafone B970 (new better, built in 3G, takes external SMA 3G antenna) and configure it it make the connection. You will then have to gateway the ASA through it. Both routers support DDNS.
3) The router will let you port forward any port to the ASA. I think they both also support a DMZ setup where you can forward just about anything to 1 device.
 
Last edited:
The above will work. I have a client running multiple Linksys/ASA devices for failover at their branches....
 
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