I'm going to replace a Sonicwall TZ 190 with a NSA 3500. Currently I have a Site to Site VPN setup on the TZ 190. I entered the exact information for the site-to-site VPN on the new NSA 3500, but I have not changed the "Unique Firewall Identifier" on the new device. Will this effect the Site to Site connection? Do I need to change the Unique Firewall Identifier on the NSA 3500 to the TZ 190 or is it OK if I leave this alone? What does the Unique Firewall Identifier effect?
In general, as long as the VPN settings are identical at both locations, you should be okay. In previous generations of products, if the UFI didn't match the SA name on the remote end of the firewall, bad things happened. This has gone away since.