Red Hat ENTERPRISE LINUX 5 - DEPLOYMENT Deployment Manual page 715

is generated when the IPsec tunnel is activated. For Workstation A, the X.X.X.X in the include
statement is Workstation B's IP address. The opposite is true of Workstation B. The following shows a
typical racoon.conf file when the IPsec connection is activated.
# Racoon IKE daemon configuration file.
# See 'man racoon.conf' for a description of the format and entries.
path include "/etc/racoon";
path pre_shared_key "/etc/racoon/psk.txt";
path certificate "/etc/racoon/certs";
sainfo anonymous
{
pfs_group 2;
lifetime time 1 hour ;
encryption_algorithm 3des, blowfish 448, rijndael ;
authentication_algorithm hmac_sha1, hmac_md5 ;
compression_algorithm deflate ;
}
include "/etc/racoon/X.X.X.X.conf";
This default racoon.conf file includes defined paths for IPsec configuration, pre-shared key files,
and certificates. The fields in sainfo anonymous describe the phase 2 SA between the IPsec nodes
— the nature of the IPsec connection (including the supported encryption algorithms used) and the
method of exchanging keys. The following list defines the fields of phase 2:
sainfo anonymous
Denotes that SA can anonymously initialize with any peer provided that the IPsec credentials
match.
pfs_group 2
Defines the Diffie-Hellman key exchange protocol, which determines the method by which the
IPsec nodes establish a mutual temporary session key for the second phase of IPsec connectivity.
By default, the Red Hat Enterprise Linux implementation of IPsec uses group 2 (or modp1024)
of the Diffie-Hellman cryptographic key exchange groups. Group 2 uses a 1024-bit modular
exponentiation that prevents attackers from decrypting previous IPsec transmissions even if a
private key is compromised.
lifetime time 1 hour
This parameter specifies the lifetime of an SA and can be quantified either by time or by bytes of
data. The default Red Hat Enterprise Linux implementation of IPsec specifies a one hour lifetime.
encryption_algorithm 3des, blowfish 448, rijndael
Specifies the supported encryption ciphers for phase 2. Red Hat Enterprise Linux supports 3DES,
448-bit Blowfish, and Rijndael (the cipher used in the Advanced Encryption Standard, or AES).
authentication_algorithm hmac_sha1, hmac_md5
Lists the supported hash algorithms for authentication. Supported modes are sha1 and md5
hashed message authentication codes (HMAC).
compression_algorithm deflate
Defines the Deflate compression algorithm for IP Payload Compression (IPCOMP) support, which
allows for potentially faster transmission of IP datagrams over slow connections.
To start the connection, use the following command on each host:
IPsec Host-to-Host Configuration
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