In addition to what Jon said one other possibility is that if you have VPN connection(s) to external vendors and they expect traffic to be sourced from 10.9.6.1 when you access their network then using this policy NAT would make sense as well. Could that be the case since you stated in your original post that you have VPN from outside sources.
We have used policy NAT for that very reason ie. the remote site needed our source IP addresses Natted but they could not accept what we were already Natting them to so we had to use a different address.
The second part of your question :- it depends
1) If the address is already in use for a different VPN then you would need the NAT to happen at the remote end because your firewall would not be able to ditinguish between the same source IP address coming from 2 different sites.
2) If the address is already in use on your local LAN you don't need policy NAT because your Natting the source IP addresses so you could do the following
nat (outside) 1 192.168.5.0 255.255.255.0 outside
global (inside) 1 172.16.5.1
In the above example the remote site is using 192.168.5.0/24 as their source IP's. You are already using these so you NAT the source IP's to 172.16.5.1 as they come into your firewall.
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...