crypto isakmp policy 10
encr 3des
hash md5
authentication pre-share
group 2
crypto isakmp key XXX address 10.10.10.10
// set your key insted of XXX and it must match with your remote site. after that write address of your peer
crypto isakmp invalid-spi-recovery
!
!
crypto ipsec transform-set XXX esp-3des esp-md5-hmac
!
crypto map YYY local-address <<<FastEthernet0/0 your local int>>>
crypto map YYY 10 ipsec-isakmp
set peer 10.10.10.10
set transform-set ZZZ
match address 101
interface <<<FastEthernet0/ your public int>>>
crypto map YYYY
access-list 101 permit ip 192.168.1.0 0.0.0.255 11.11.11.11 (Remote user) 255.255.255.255
access-list 101 permit ip 192.168.1.0 0.0.0.255 22.22.22.22(Remote user) 255.255.255.255
After that configure NAT with req. access-list
For troubleshooting
sh cry ipsec sa peer 10.10.10.10
sh cry session
hope your IPSec site to site VPN tunnel is working fine
