Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 
Community Member

Help urgent CEF/ Firewall / VPN


I have a customer that would like to implement VPN between their office and a remote office ASAP, they just order another t1 to implement CEF(load balance) with 2 t1’s with existing 1720 router, I know that we can do that with this particular router, I was wondering what version of IOS release should be used and what’s the minimum memory needed for this implementation.

They have a 1 WIC-1DSU-T1 DSU\CSU installed, I need to order another one, should that work for me and just upgrade the IOS or do I have to order 2x WIC-1DSU-T1 8/32 VPN/FW/3DES since has a built in Firewall / VPN functionality

Also there is a need of a firewall to be added to the network, the client is a small office and a budget is definitely a plus to consider, can we use this router to function with all 3 options or should we get a separate PIX for the effect.

I am not an expert on PIX / Firewall, so If possible I would like to get ideas or links for the configs to implement all 3 VPN / CEF / Firewall. any ideas would be appreciated.

Thank you all in advance for any ideas, I am definitely stuck with no answers for my customer.



Re: Help urgent CEF/ Firewall / VPN

12.2(1) supports the feature set 'IP/FW/IDS PLUS IPSEC 56', CEF/dCEF and runs on 1720. It needs 32 Mb RAM and 8 Mb Flash.

Please have a look at 'How to Choose a Cisco IOS. Software Release' at This document will solve a lot of your problems when it comes to figuring out a suitable IOS version.

Some additional info: My search for 1720 with WIC-1DSU-T1, returned the following: 12.0(2)T, 12.0(1)XA, 12.1(1), 12.1(1)T, 12.2(1), 12.2(2)T, 12.2(2)XK, 12.2(8)YJ, 12.2(8)YL, 12.2(8)YM, 12.2(8)YN, 12.3(1).

My search for 1720 with CEF returned over 160 results. You'll need to shortlist the listdepending on feature set you want (IPSec, firewall etc).

12.2(1) figured in both the lists.

CreatePlease to create content