Setting Keepalive Timers; Setting The Nat Keepalive Timer - HP 5500 HI Series Configuration Manual

Step
11. Apply a DPD detector to the
IKE peer.
NOTE:
After modifying the configuration of an IPsec IKE peer, execute the reset ipsec sa and reset ike sa
commands to clear existing IPsec and IKE SAs. Otherwise, SA re-negotiation will fail.

Setting keepalive timers

IKE maintains the link status of an ISAKMP SA by keepalive packets. Generally, if the peer is configured
with the keepalive timeout, you must configure the keepalive packet transmission interval on the local end.
If the peer receives no keepalive packet during the timeout interval, the ISAKMP SA will be tagged with
the TIMEOUT tag (if it does not have the tag), or be deleted along with the IPsec SAs it negotiated (when
it has the tag already).
To set the keepalive timers:
Step
1. Enter system view.
2. Set the ISAKMP SA keepalive
interval.
3. Set the ISAKMP SA keepalive
timeout.
NOTE:
The keepalive timeout configured at the local end must be longer than the keepalive interval configured at
the remote end. Since it seldom occurs that more than three consecutive packets are lost on a network, the
keepalive timeout can be configured to be three times of the keepalive interval.

Setting the NAT keepalive timer

If IPsec traffic needs to pass through NAT security gateways, you must configure the NAT traversal
function. If no packet travels across an IPsec tunnel in a certain period of time, the NAT mapping may get
aged and be deleted, disabling the tunnel beyond the NAT gateway from transmitting data to the
intended end. To prevent NAT mappings from being aged, an ISAKMP SA behind the NAT security
gateway sends NAT keepalive packets to its peer at a certain interval to keep the NAT session alive.
To set the NAT keepalive timer:
Step
1. Enter system view.
Command
dpd dpd-name
Command
system-view
ike sa keepalive-timer interval
seconds
ike sa keepalive-timer timeout
seconds
Command
system-view
294
Remarks
Optional.
No DPD detector is applied to an
IKE peer by default.
For more information about DPD
configuration, see "Configuring a
DPD detector."
Remarks
N/A
No keepalive packet is sent by
default.
No keepalive packet is sent by
default.
Remarks
N/A