i have 29ips in one server(ros vpn server, only 1 wan Interface)
Example: 66.152.172.2 to 66.152.172.30

i hope use any ip to Connection vpn, nat the ip to internet
how can set routeros??? in connection ip and vpn remote ip i can't find any relationship, so cant to set mark.

please help me out. thx!

Use src-nat instead of masquerade as an action and specify the desired IP address. You can spread NAT load over the the pool of IPs randomly, evenly or by inside network segments by having multiple src-nat rules that either use "random", "nth" or refer to an address-list or smaller prefix.

"VPN" is too broad, be more specific on what VPN protocols you're actually using.

for pptp, you can setup public IPs for clients directly

i want use one pptp account conn to vpn, conn to A ip and snat A ip to internet, conn B ip and snat Bip to internet.

ummm... an more detailed example? I cannot understand you...

^^, my English is not good.

ros:
wan: 1.1.1.2 -> 1.1.1.10
pool: 192.168.10.0/24

vpn:
account: aaa
pass: bbb

if i use aaa conn to ros 1.1.1.2, snat to 1.1.1.2
if i use aaa conn to ros 1.1.1.3, snat to 1.1.1.3
if i use aaa conn to ros 1.1.1.4, snat to 1.1.1.4
......

yep, just checked - added another address to my pptp server and tried to establish pptp to that address. in my RADIUS, I saw that 'server' and 'client_ip' are first address of the server...

you may write to support - maybe they can change ROS behaviour, so that it reported the IP the client is connecting to, not the IP from Pref.Src of routing table...