Well for starters make sure your routers have IPSec capabilities.
I have 3 offices connected by DSL.Head Office has a 128K link and the two remote offices have links of 64K.Head Office has a Cisco 2600 series router while the two branch offices have Cisco 1700 series routers.I want to implement VPN among the three offices.What am I supposed to make sure my three routers have to make sure VPN can be configured on them and how do i go about configuring it.Any help will be highly appreciated.
