VPN

I have a m0n0 with a static ip and some vpn router with dynamic ip, the vpn router has binding ddns, the tunnels established if i specify the ip in m0n0's remote gateway, but the tunnels could not established between m0n0 and vpn router when i used specify the ddns instead of ip. I wonder how to ravel out this problem, thanks a lot!

yes it is possible. I have the same setup from static to dynamic. If the dynamic connection is on cable like road runner, then you will have no problems. Just make sure that you have both ends configured the same, except for the IP of course. Also do you know what sort of errors you are recieving.

but pfsense side remote gateway can't specify a dns, otherwise pfsense can't resolve it.

there is my syslog about ipsec below:

May 2 13:31:46 racoon: ERROR: fatal parse failure.
May 2 13:31:46 racoon: ERROR: getaddrinfo(fe,500): hostname nor servname provided, or not known
May 2 13:31:46 racoon: INFO: @(#)This product linked OpenSSL 0.9.7e-p1 25 Oct 2004 (http://www.openssl.org/)
May 2 13:31:46 racoon: INFO: @(#)ipsec-tools 0.6.6 (http://ipsec-tools.sourceforge.net)

Try entering a DNS override on the firewall for the name you wish to give the other IP address.  Then all you need to do is update that dDNS entry in the event the other side's IP address changes.  And of course, your firewall will be able to resolve the FQDN and find the machine.

Why don't you use the Mobile Clients of m0n0?
I'm using it and my home network behind an ADSL router is very well connected with my office's m0n0 and it's LAN, of course.