3Com S7906E - Switch, Configuration Manual

Page: 473 / 2621

1-17
To do… Use the command… Remarks
Configure the number of
attempts to send an NS
message for DAD
ipv6 nd dad attempts value
Optional
1 by default. When the value
argument is set to 0, DAD is
disabled.
Configuring PMTU Discovery
Configuring a Static PMTU for a Specified IPv6 Address
You can configure a static PMTU for a specified destination IPv6 address. When a source host sends a
packet through an interface, it compares the interface MTU with the static PMTU of the specified
destination IPv6 address. If the packet size is larger than the smaller one between the two values, the
host fragments the packet according to the smaller value.
Follow these steps to configure a static PMTU for a specified address:
To do… Use the command… Remarks
Enter system view
system-view
—
Configure a static PMTU for a
specified IPv6 address ipv6 pathmtu ipv6-address
[ value ]
Required
By default, no static PMTU is
configured.
Configuring the Aging Time for Dynamic PMTUs
After the path MTU from a source host to a destination host is dynamically determined (refer to IPv6
PMTU Discovery , the source host sends subsequent packets to the destination host on basis of this
MTU. After the aging time expires, the dynamic PMTU is removed and the source host re-determines a
dynamic path MTU through the PMTU mechanism.
The aging time is invalid for a static PMTU.
Follow these steps to configure the aging time for dynamic PMTUs:
To do… Use the command… Remarks
Enter system view system-view —
Configure the aging time for
dynamic PMTUs
ipv6 pathmtu age age-time
Optional
10 minutes by default.
Configuring IPv6 TCP Properties
The IPv6 TCP properties you can configure include:
z
synwait timer: When a SYN packet is sent, the synwait timer is triggered. If no response packet is
received before the synwait timer expires, the IPv6 TCP connection establishment fails.
z
finwait timer: When the IPv6 TCP connection status is FIN_WAIT_2, the finwait timer is triggered. If
no packet is received before the finwait timer expires, the IPv6 TCP connection is terminated. If a
FIN packet is received, the IPv6 TCP connection status becomes TIME_WAIT. If non-FIN packets