I am trying to setup a site to site VPN tunnel, between two networks, one with a Sophos UTM, the other a Cisco 5515X. The ASA side of the tunnel is configured with a public peer, private address subnet (192.168.71.0) while the Sophos side is compelled to use the same IP address as tunnel peer and host (18.104.22.168 - this is a fake address.) Tunnel is up, I can see traffic passing through it from the Sophos UTM's network, but there is nothing coming back out from the Cisco side. This is my first time having to configure an ASA for this, and I am completely stumped.
Please can someone tell me what I am missing? My Cisco ASA configuration is below.
crypto ipsec ikev1 transform-set REMOTE_LOCAL esp-3des esp-md5-hmac crypto ipsec security-association pmtu-aging infinite crypto map REMOTE2LOCAL 1 match address REMOTE_to_LOCAL crypto map REMOTE2LOCAL 1 set pfs crypto map REMOTE2LOCAL 1 set peer 22.214.171.124 crypto map REMOTE2LOCAL 1 set ikev1 transform-set REMOTE_LOCAL crypto map REMOTE2LOCAL interface outside crypto ca trustpool policy crypto ikev1 enable outside crypto ikev1 policy 10 authentication pre-share encryption 3des hash md5 group 2 lifetime 86400 crypto ipsec ikev1 transform-set REMOTE_LOCAL esp-3des esp-md5-hmac object network mgmt71vpn subnet 192.168.71.0 255.255.255.0 object network REMOTE.50 host 126.96.36.199 nat (inside,outside) source static mgmt71vpn mgmt71vpn destination static REMOTE.50 REMOTE.50 no-proxy-arp route-lookup access-list REMOTE_to_LOCAL extended permit ip object mgmt71vpn object REMOTE.50 access-list outside_in extended permit ip host 188.8.131.52 192.168.71.0 255.255.255.0 access-group outside_in in interface outside