Since you already have the 2620 routers at the remote sites, option 2 will be cost saving design. You can use High Availability feature at the Central site, and IOS firewall at the remote sites. This is a sample configuration of HA,
1)Yes, the PIX also uses DPD (dead peer detection) this is necessary for your HA configuration.
2) It is recommended to use a Dynamic routing protocol, the HSRP address will be on the outside, your routing protocol will point to the interface that is going to be active and viewable from the inside.
Login to the FXOS chassis manager.
Direct your browser to https://hostname/, and log-in using the user-name and password.
Go to Help > About and check the current version:
Check the current version availa...
We have configured the outside and inside Interface with official ipv6 adresses, set a default route on outside Interface to our router, we also have definied a rule , which also gets hits, to permit tcp from inside Interface to any6.
In Syslog I also se...