User manual

Virtual Private Networking
207
• SPI Number is the Security Parameters Index. It is a hexadecimal value and must
be unique. It is used to establish and uniquely identify the tunnel. The SPI is used to
determine which key is used to encrypt and decrypt the packets. It must be of the
form 0xhex, where hex is one or more hexadecimal digits and be in the range of
0x100-0xfff. This field appears when Manual Keying has been selected.
• Authentication Key is the ESP Authentication Key. It must be of the form 0xhex,
where hex is one or more hexadecimal digits. The hex part must be exactly 32
characters long when using MD5 or 40 characters long when using SHA1 (excluding
any underscore characters). This field appears when Manual Keying has been
selected.
• Encryption Key is the ESP Encryption Key. It must be of the form 0xhex, where hex
is one or more hexadecimal digits. The hex part must be exactly 16 characters long
when using DES or 48 characters long when using 3DES (excluding any underscore
characters). This field appears when Manual Keying has been selected.
• Cipher and Hash pull down menu contains the ESP encryption/authentication
algorithms that can be used for the tunnel. The option selected must correspond to
the encryption and authentication keys used. This pull down menu appears when
Manual Keying has been selected. The options include the following:
o 3des-md5-96 uses the encryption transform following the Triple-DES standard in
Cipher-Block-Chaining mode with authentication provided by HMAC and MD5
(96-bit authenticator). It uses a 192-bit 3DES encryption key and a 128-bit
HMAC-MD5 authentication key.
o 3des-sha1-96 uses the encryption transform following the Triple-DES standard in
Cipher-Block-Chaining mode with authentication provided by HMAC and SHA1
(96-bit authenticator). It uses a 192-bit 3DES encryption key and a 160-bit
HMAC-SHA1 authentication key.
o des-md5-96 uses the encryption transform following the DES standard in Cipher-
Block-Chaining mode with authentication provided by HMAC and MD5 (96-bit
authenticator). It uses a 56-bit 3DES encryption key and a 128-bit HMAC-MD5
authentication key.
o des-sha1-96 uses the encryption transform following the DES standard in Cipher-
Block-Chaining mode with authentication provided by HMAC and SHA1 (96-bit
authenticator). It uses a 56-bit DES encryption key and a 160-bit HMAC-SHA1
authentication key.
• Local Network is the network behind the local SG unit. This field appears when
Manual Keying has been selected.