Configure settings to enable use of IPsec. Also, specify the policy for IPsec communication.
In [IPsec Setting], register items [IKE], [SA], [Peer], and [Protocol Setting].
When using IPsec, set this option to ON (default: OFF).
[Dead Peer Detection]
If no response can be confirmed from the peer in a certain period, the SA with the peer is deleted. Select a time that elapses before sending survival confirmation information to the peer how has not responded (default:  sec.).
Select whether to enable the defense using Cookies against denial-of-service attacks (default: [Disable]).
Select whether to apply IPsec to the Internet Control Message Protocol (ICMP) (default: [Disable]). Select [Enable] to allow the ICMP packets to pass without applying IPsec to the ICMP.
Select whether to apply IPsec to the Internet Control Message Protocol for IPv6 (ICMPv6) (default: [Disable]). Select [Enable] to allow the ICMPv6 packets to pass without applying IPsec to the ICMPv6.
Select an action to be taken if no settings meet the [IPsec Policy] while IPsec communication is enabled (default: [Allow]). Select [Deny] to discard IP packets that do not meet the [IPsec Policy] settings.
[Certificate Verification Level Settings]
To verify the certificate, select items to be verified.
Configure the policy to apply for IPsec communication.
IP packet conditions can be specified to pass or allow the IP packets that meet each of the conditions.