Specifications
Altitude 4700 Series Access Point Product Reference Guide
233
The Inbound and Outbound SPI settings are required to be interpolated to function correctly. For 
example:
● AP1 Inbound SPI = 800
● AP1 Outbound SPI = 801
● AP2 Inbound SPI = 801
● AP2 Outbound SPI = 800
4 Click Ok to return to the VPN screen. Click Apply to retain the settings made on the Manual Key 
Settings screen. 
5 Click Cancel to return to the VPN screen without retaining the changes made to the Manual Key 
Settings screen.
Configuring Auto Key Settings
The access point’s Network Management System can automatically set encryption and authentication 
keys for VPN access. Use the Auto Key Settings screen to specify the type of encryption and 
authentication, without specifying the keys. To manually specify keys, cancel out of the Auto Key 
Settings screen, select the Manual Key Exchange radio button, and set the keys within the Manual Key 
Setting screen.
ESP Authentication 
Algorithm
Select the authentication algorithm to use with ESP. This 
option is available only when ESP with Authentication was 
selected for the ESP type. Options include:
• MD5—Enables the Message Digest 5 algorithm, which 
requires 128-bit (32-character hexadecimal) keys. 
• SHA1—Enables Secure Hash Algorithm 1, which 
requires 160-bit (40-character hexadecimal) keys. 
Inbound ESP 
Authentication Key
Define a key for computing the integrity check on the 
inbound traffic with the selected authentication algorithm. 
The key must be 32/40 (for MD5/SHA1) hexadecimal (0-9, 
A-F) characters in length. The key must match the 
corresponding outbound key on the remote security 
gateway. 
Outbound ESP 
Authentication Key
Enter a key for computing the integrity check on outbound 
traffic with the selected authentication algorithm. The key 
must be 32/40 (for MD5/SHA1) hexadecimal (0-9, A-F) 
characters in length. The key must match the 
corresponding inbound key on the remote security 
gateway.
Inbound SPI (Hex)  Define an (up to) six-character (maximum) hexadecimal 
value to identify the inbound security association created 
by the encryption algorithm. The value must match the 
corresponding outbound SPI value configured on the 
remote security gateway.
Outbound SPI 
(Hex)
Enter an (up to) six-character (maximum) hexadecimal 
value to identify the outbound security association created 
by the encryption algorithm. The value must match the 
corresponding inbound SPI value configured on the remote 
security gateway.










