Problem with the Host2Host IPsec configuration

[Liloulinx]

Hi,
I'm under FC4. I would like to configure an IPsec communications between 
2 computers. The first has the IP "10.172.52.78" and the second has the 
IP : "10.172.52.19". To do this I have used the "Network Configuration" 
tool (/usr/bin/system-config-network).
In the "IPsec" tab, I have pushed on "new". And do this:
 - surname: AAA
 - IPsec on boot= false
 - type of connection: Host 2 host
 - type of encryption: by IKE (racoon)
 - remote IP address: 10.172.52.19
 - Authentication key: c7f6fac78b603ecaa6dc9817f596da6141369604
 - incoming authentication SPI: 300
 - outgoing authentication SPI: 301
 - incoming encryption SPI: 302
 - outcoing encryption SPI: 303

In the second machine I have done the same, else for:
 - remote IP address: 10.172.52.78
 - incoming authentication SPI: 301
 - outgoing authentication SPI: 300
 - incoming encryption SPI: 303
 - outcoing encryption SPI: 302

I have saved the new rule in each machine. I have enabled it and 
restarted the network daemon.
In each machine I have obtained these files: 
/etc/sysconfig/network-scripts/ifcfg-AAA, 
/etc/sysconfig/network-scripts/keys-AAA, /racoon/10.172.52.19.conf (and 
the in the 2nd machine /racoon/10.172.52.78.conf)

- Contents of the "/etc/sysconfig/network-scripts/ifcfg-AAA" file:
   DST=10.172.52.19
   TYPE=IPSEC
   ONBOOT=no
   IKE_METHOD=PSK

-Content of the /etc/keys-AAA file:
   c7f6fac78b603ecaa6dc9817f596da6141369604

- Contents of the "/etc/racoon/10.172.52.19.conf" file
  remote 10.172.52.19
  {
      exchange_mode aggressive, main;
      my_identifier address;
      proposal {
              encryption_algorithm 3des;
          hash_algorithm sha1;
          authentication_method pre_shared_key;
          dh_group 2 ;
      }
  }



Problem: When I try to ping the other machine I have this error message:
        ping  10.172.52.19
        connect: Resource temporarily unavailable
Nota: I have disabled my firewall.

Do you know what I must do in addition to what I made?
Thanks