Cisco Linksys WAG54GX2 User Manual page 53

Wireless-G ADSL Gateway with SRX200
Manual
If you select Manual, you generate the key yourself, and no key negotiation is needed. Basically, manual key
management is used in small static environments or for troubleshooting purposes.
• Encryption Algorithm. When you select Manual, 3DES (168-bit) encryption is automatically selected. The
same type of encryption must be used by the VPN device at the remote end of the tunnel.
• Encryption Key. This field specifies a key used to encrypt and decrypt IP traffic. The Encryption Key is
48-bit, so you should enter a key of 24 ASCII characters. Make sure both ends of the VPN tunnel use the
same Encryption Key.
• Authentication Algorithm. Select a method of authentication, MD5 or SHA1. This determines how the ESP
packets are validated. MD5 is a one-way hashing algorithm that produces a 128-bit digest. SHA is a one-
way hashing algorithm that produces a 160-bit digest. SHA1 is recommended because it is more secure.
Make sure both ends of the VPN tunnel use the same authentication method.
• Authentication Key. This field specifies a key used to authenticate IP traffic. Enter a key of hexadecimal
values. If MD5 is selected, the Authentication Key is 32-bit, so you should enter 16 ASCII characters. If
SHA is selected, the Authentication Key is 40-bit, so you should enter a key of 20 ASCII characters. Make
sure both ends of the VPN tunnel use the same Authentication Key.
• Inbound and Outbound SPI (Security Parameter Index). SPI is carried in the ESP (Encapsulating Security
Payload Protocol) header and enables the receiver and sender to select the SA, under which a packet
should be processed. Hexadecimal values is acceptable, and the valid range is 100~ffffffff. Each tunnel
must have a unique Inbound SPI and Outbound SPI. No two tunnels share the same SPI. The Incoming SPI
here must match the Outgoing SPI value at the other end of the tunnel, and vice versa.
Status
The status information for the Gateway's VPN tunnels is displayed here.
If you selected Manual, then you will have one button available. Click the View Log button to see the activity logs.
If you selected Auto (IKE), then you will have four buttons available. Click the Connect button to start the VPN
connection.Click the Disconnect button to terminate the VPN connection. Click the View Log button to see the
activity logs. Click the Advanced Settings button to configure the advanced settings of the VPN tunnel.
Chapter 6: Configuring the Wireless-G ADSL Gateway with SRX200
The Security Tab
Figure 6-30: Key Exchange Method - Manual
Figure 6-31: VPN Log
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