Hello, I'm running some NAT rules to nat private users IPs within a public nat pool, about 16 Ips.
I guess and I hope, if there is any way to avoid changing public IP "randomly", and keep a stable mapping based on source ip, to prevent users from getting different public IPs in each outgoing packet. This behavior leads to problems with some web applications/games.

Here's my nat rule:
chain=srcnat action=src-nat to-addresses=****/28 src-address=10.49.251.0/25

use netmap instead of src-nat it will work

Just a remark, nat acts per connection, not per packet, so all packets belonging to the same connection (e.g. a TCP session) will have the same public address even with action=src-nat. But as @loloski wrote, action=netmap will make sure that all connections from a given private address will be src-nated to the same public address.

Thank you I'll investigate netmap.
Best regards!