Configuring A Dpd Detector; Disabling Next Payload Field Checking - HP 5120 SI Series Security Configuration Manual

Step
2. Set the NAT keepalive
interval.

Configuring a DPD detector

Dead peer detection (DPD) irregularly detects dead IKE peers. It works as follows:
1. When the local end sends an IPsec packet, it checks the time the last IPsec packet was received
from the peer.
2. If the time interval exceeds the DPD interval, it sends a DPD hello to the peer.
3. If the local end receives no DPD acknowledgement within the DPD packet retransmission interval,
it retransmits the DPD hello.
4. If the local end still receives no DPD acknowledgement after having made the maximum number of
retransmission attempts (two by default), it considers the peer already dead, and clears the IKE SA
and the IPsec SAs based on the IKE SA.
DPD enables an IKE entity to check the liveliness of its peer only when necessary. It generates less traffic
than the keepalive mechanism, which exchanges messages periodically.
To configure a DPD detector:
Step
1. Enter system view.
2. Create a DPD detector and
enter its view.
3. Set the DPD interval.
4. Set the DPD packet
retransmission interval.

Disabling next payload field checking

The Next payload field is in the generic payload header of the last payload of the IKE negotiation
message (the message comprises multiple payloads). According to the protocol, this field must be 0 if the
payload is the last payload of the packet. However, it may be set to other values on some brands of
devices. For interoperability, disable the checking of this field.
To disable Next payload field checking:
Step
Enter system view.
Disable Next payload field
checking.
Command
ike sa nat-keepalive-timer interval
seconds
Command
system-view
ike dpd dpd-name
interval-time interval-time
time-out time-out
Command
system-view
ike next-payload check disabled
362
Remarks
20 seconds by default.
Remarks
N/A
N/A
Optional.
10 seconds by default.
Optional.
5 seconds by default.
Remark
N/A
Enabled by default.