Configuring Ike Dpd; Enabling Invalid Spi Recovery - H3C S5830V2 Security Configuration Manual

To configure the IKE NAT keepalive function:
Step
1. Enter system view.
2. Set the IKE NAT keepalive
interval.

Configuring IKE DPD

DPD detects dead peers. It can operate in periodic mode or on-demand mode.
Periodic DPD—Sends a DPD message at regular intervals. It features an earlier detection of dead
•
peers, but consumes more bandwidth and CPU.
• On-demand DPD—Sends a DPD message based on traffic. When the device has traffic to send and
is not aware of the liveness of the peer, it sends a DPD message to query the status of the peer. If the
device has no traffic to send, it never sends DPD messages. This mode is recommended.
The IKE DPD works as follows:
1. The local device sends a DPD message to the peer, and waits for a response from the peer.
2. If the peer does not respond within the retry interval specified by the retry seconds parameter, the
local device resends the message.
3. If still no response is received within the retry interval, the local send the DPD message again. The
system allows a maximum of two retries.
4. If the local device receives no response after two retries, the device considers the peer is dead, and
deletes the IKE SA along with the IPsec SAs it negotiated.
5. If the local device receives a response from the peer during the detection process, the peer is
considered alive. The local device performs a DPD detection again when the triggering interval is
reached or it has traffic to send, depending on the DPD mode.
Follow these guidelines when you configure the IKE DPD function:
When DPD settings are configured in both IKE profile view and system view, the DPD settings in IKE
•
profile view apply. If DPD is not configured in IKE profile view, the DPD settings in system view apply.
• It is a good practice to set the triggering interval longer than the retry interval so that a DPD
detection is not triggered during a DPD retry.
To configure IKE DPD:
Step
1. Enter system view.
2. Enable sending IKE DPD
messages.

Enabling invalid SPI recovery

An IPsec "black hole" occurs when one IPsec peer fails (for example, a peer can fail if a reboot occurs).
One peer fails and loses its SAs with the other peer. When an IPsec peer receives a data packet for
Command
system-view
ike nat-keepalive seconds
Command
system-view
ike dpd interval interval-seconds
[ retry seconds ] { on-demand |
periodic }
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Remarks
N/A
The default interval is 20 seconds.
Remarks
N/A
By default, IKE DPD is disabled.