On Fri, 18 Jan 2008, Gene Spiker wrote:

Other versions of IPSec on other systems that work off a menu such as winbox also build the interface and route.

Mikrotik uses a POLICY to route the traffic...there is not a route (at least not one visible under "/ip route") for IPSEC traffic.

In version 2.9 of Mikrotik I manually built a route for the remote subnet pointing to the Mikrotik IP address of the Mikrotik LAN. This did not work.

Because it's not necessary. What you need to do is add configurations as follows (this is not exact, but a GUIDE):

under "/ip ipsec policy", you define the following 4 values as appropriate:
src-address = the lan network address on the MT side
dst-address = the lan network address on the IPCOP side
sa-src-address = the PUBLIC IP on the MT side
sa-dst-address = the PUBLIC IP on the IPCOP side

The remainder of the ipsec config is likely to be correct, since you can communicate across the tunnel.

under "/ip firewall nat", you should run these commands:

/ip firewall nat print
/ip firewall nat
    add src-address=MTLAN dst-address=IPCOPLAN action=accept \
      place-before=0

of course, the "MTLAN" is the network address for the private subnet on the MT side and IPCOPLAN is the IPCOP side. WHat this does, is cause traffic destined for the remote side of the tunnel to NOT be natted (assuming you are natting on the public side). This is necessary because the NAT happens before the IPSEC part of the kernel, meaning that if the traffic is being natted, the IPSEC does not see traffic that matches the policy and, therefore, does not send it across the tunnel.

There is no need for routes or setting of proxy-arp. MT does not add any IP addresses or visible interfaces for IPSEC tunnels.

After you set this up, you should be able to ping from one private lan to the other. You should see (under "/ip ipsec installed-sa") 2 tunnels - one in and one out.

The documentation says this, but (unlike most other parts of MT's documentation) I think this part is not very clear.

--
Butch Evans
Network Engineering and Security Consulting
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