Netgear SRX5308 SRX5308 Reference Manual - Page 169

ProSafe Gigabit Quad WAN SSL VPN Firewall SRX5308 Reference Manual Table 5-10. Add IKE Policy Settings (continued) Item Description (or Subfield and Description) Authentication Algorithm From the drop-down list, select one of the following two algorithms to use in the VPN header for the authentication process: • SHA-1. Hash algorithm that produces a 160-bit digest. This is the default setting. • MD5. Hash algorithm that produces a 128-bit digest. Authentication Method Select one of the following radio buttons to specify the authentication method: • Pre-shared key. A secret that is shared between the VPN firewall and the remote endpoint. • RSA-Signature. Uses the active self certificate that you uploaded on the Certificates screen (see "Managing Self Certificates" on page 7-20). The pre-shared key is masked out when you select the RSA-Signature option. Pre-shared key A key with a minimum length of 8 characters no more than 49 characters. Do not use a double quote (") in the key. Diffie-Hellman (DH) Group The DH Group sets the strength of the algorithm in bits. The higher the group, the more secure the exchange. From the drop-down list, select one of the following three strengths: • Group 1 (768 bit). • Group 2 (1024 bit). This is the default setting. • Group 5 (1536 bit). Note: Ensure that the DH Group is configured identically on both sides. SA-Lifetime (sec) The period in seconds for which the IKE SA is valid. When the period times out, the next rekeying must occur. The default is 28800 seconds (8 hours). Enable Dead Peer Detection Note: See also "Configuring Keepalives and Dead Peer Detection" on page 5-55. Select a radio button to specify whether or not Dead Peer Detection (DPD) is enabled: • Yes. This feature is enabled. When the VPN firewall detects an IKE connection failure, it deletes the IPsec and IKE SA and forces a reestablishment of the connection. You must specify the detection period in the Detection Period field and the maximum number of times that the VPN firewall attempts to reconnect in the Reconnect after failure count field. • No. This feature is disabled. This is the default setting. Detection Period The period in seconds between consecutive "DPD R-U-THERE" messages, which are sent only when the IPsec traffic is idle. The default is 10 seconds. Reconnect after failure count The maximum number of DPD failures before the VPN firewall tears down the connection and then attempts to reconnect to the peer. The default is 3 failures. Virtual Private Networking Using IPsec Connections v1.0, April 2010 5-27