Site-to-site between Pfsense 2.01 and m0n0wall

[witekprytek]

Hi all;
I need to establish IPSEC connection between m0n0wall and pfsense.
m0n0wall has no static IP and use dyndns service.

I have configured tunnel with "agressive"  mode for phase 1. m0n0wall use "domain name" as his identifier.
What should I use in pfsense configuration as peer identifier?
"distinguished name"?  "user distinguished name"? "ASN 1 distinguished name"?

In m0n0wall side I have otions: IP address, my IP address, domain name, FQDN, and RSA CERT subject
In pfsense IP address, peer IP address, distinguished name, user distinguished name, ASN 1 distinguished name, key ID tag
Could somebody explain what these options mean (in pfsense)?