Edimax Technology ER-1088 - Manual (Page 63)

Figure 6-3: IPSec Policy Options
Settings – IPSec Policy Options
Dead Peer Detection
Feature • Dead Peer Detection (DPD) – If set to Enable, a device will
periodically send HELLO/ACK messages to check if the tunnel is
alive when both peers of a VPN tunnel provide DPD mechanism.
Once a dead peer is detected, a device will end the connection so it
can be re-established. This is the primary method of VPN failover or
backup.
• Detection – If set to Enable, this will enable the following Check
Method which you have selected to work:
• Check Method:
1. Heartbeat – Sends a unidirectional (‘HELLO’ only) message to
determine connection aliveness.
2. ICMP Host – It uses ICMP packets to determine connection
aliveness
3. DPD (RFC 3706) – Uses a bi-directional (‘HELLO/ACK’) message
to determine connection aliveness.
• Check After Idle – Indicates the time period in which no traffic
Page 59