R211x-HP Flexfabric 11900 Security Command Reference

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IPsec anti-replay checking, when enabled, is performed before the de-encapsulation process, reducing
resource waste.
In some situations, service data packets are received in a different order than their original order. The
IPsec anti-replay function drops them as replayed packets, which impacts communications. If this
happens, disable IPsec anti-replay checking or adjust the size of the anti-replay window as required.
IPsec anti-replay checking does not affect manually created IPsec SAs. According to the IPsec protocol,
only IPsec SAs negotiated by IKE support anti-replay checking.
Examples
# Enable IPsec anti-replay checking.
<Sysname> system-view
[Sysname] ipsec anti-replay check
Related commands
ipsec anti-replay window
ipsec anti-replay window
Use ipsec anti-replay window to set the anti-replay window size.
Use undo ipsec anti-replay window to restore the default.
Syntax
ipsec anti-replay window width
undo ipsec anti-replay window
Default
The anti-replay window size is 64.
Views
System view
Predefined user roles
network-admin
mdc-admin
Parameters
width: Specifies the size for the anti-replay window. It can be 64, 128, 256, 512, or 1024 packets.
Usage guidelines
Changing the anti-replay window size affects only the IPsec SAs negotiated later.
In some cases, some service data packets might be received in a very different order than their original
order, and the IPsec anti-replay function might drop them as replayed packets, affecting normal
communications. If this happens, disable IPsec anti-replay checking or adjust the size of the anti-replay
window as required.
Examples
# Set the size of the anti-replay window to 128.
<Sysname> system-view
[Sysname] ipsec anti-replay window 128