486
Views
System view
Predefined user roles
network-admin
Parameters
clear
: Clears the DF bit in the outer IP header. IPsec packets can be fragmented.
copy
: Copies the DF bit setting of the original IP header to the outer IP header.
set
: Sets the DF bit in the outer IP header. IPsec packets cannot be fragmented.
Usage guidelines
This command is effective only when the IPsec encapsulation mode is tunnel mode. It is not effective
in transport mode because the outer IP header is not added in transport mode.
This command does not change the DF bit for the original IP header of IPsec packets.
Packet fragmentation and reassembly might cause packet forwarding to be delayed. You can set the
DF bit to avoid the forwarding delay. However, to prevent IPsec packets from being discarded, you
must make sure the path MTU is larger than the IPsec packet size. As a best practice, clear the DF
bit if you cannot make sure the path MTU is larger than the IPsec packet size.
Examples
# Set the DF bit in the outer IP header of IPsec packets on all interfaces.
<Sysname> system-view
[Sysname] ipsec global-df-bit set
Related commands
ipsec df-bit
ipsec limit max-tunnel
Use
ipsec limit max-tunnel
to set the maximum number of IPsec tunnels.
Use
undo ipsec limit max-tunnel
to restore the default.
Syntax
ipsec limit max-tunnel tunnel-limit
undo ipsec limit max-tunnel
Default
The number of IPsec tunnels is not limited.
Views
System view
Predefined user roles
network-admin
Parameters
tunnel-limit
: Specifies the maximum number of IPsec tunnels, in the range of 1 to 4294967295.
Usage guidelines
To maximize concurrent performance of IPsec when memory is sufficient, increase the maximum
number of IPsec tunnels. To ensure service availability when memory is insufficient, decrease the
maximum number of IPsec tunnels.