Well , it is a simple task like others said , using IOS IPsec features as long as your IOS image has a ***K9** version. Your current ios version support it. You could use IPSEC site-to-site using pre-shared-key method or use digital certificate method. For not disturbing  your live traffic you could simulate using Dynampis or GNS3 emulator first and then apply the config to the real router. But don`t forget it will increase a little bit of your router CPU and Memory consumption after apply the ipsec.

rgrds

CSA



mwapetech <mwapetech@...> wrote:

I have two Cisco Routers model C2851 with IOS
c2800nm-ipvoicek9-mz.124-3g. These two routers are acting as peer
routers between a Fiber WAN link. I would like to encrypt data between
my two private networks that are behind these two routers, without
using a Certificate Authority (CA). Anyone with configuration or
idea of how to go about it.

DM.