3Com Switch 4800G 24-Port Configuration Manual page 511

Configuring Parameters
Related to an RA
Message
n
To do...
Enter system view
Enter interface view
Configure the maximum
number of neighbors
dynamically learned by an
interface
You can configure whether the interface sends an RA message, the interval for
sending RA messages, and parameters in RA messages. After receiving an RA
message, a host can use these parameters to perform corresponding operations.
Table 50 lists the configurable parameters in an RA message and their
descriptions.
Table 50 Parameters in an RA message and their descriptions
Parameters Description
Cur hop limit When sending an IPv6 packet, a host uses the value of this parameter to fill
the Cur Hop Limit field in IPv6 headers. Meanwhile, the value of this
parameter is equal to the value of the Cur Hop Limit field in response
messages of the device.
Prefix After receiving the prefix information advertised by the device, the hosts on
information the same link can perform stateless autoconfiguration operations.
options
M flag This field determines whether hosts use the stateful autoconfiguration to
acquire IPv6 addresses.
If the M flag is set to 1, hosts use the stateful autoconfiguration to acquire
IPv6 addresses. Otherwise, hosts use the stateless autoconfiguration to
acquire IPv6 addresses, that is, hosts configure IPv6 addresses according to
their own link-layer addresses and the prefix information issued by the
router.
O flag This field determines whether hosts use the stateful autoconfiguration to
acquire information other than IPv6 addresses.
If the O flag is set to 1, hosts use the stateful autoconfiguration (for
example, DHCP server) to acquire information other than IPv6 addresses.
Otherwise, hosts use the stateless autoconfiguration to acquire information
other than IPv6 addresses.
Router lifetime This field is used to set the lifetime of the router that sends RA messages to
serve as the default router of hosts. According to the router lifetime in the
received RA messages, hosts determine whether the router sending RA
messages can serve as the default router of hosts.
Retrans timer If the device fails to receive a response message within the specified time
after sending an NS message, the device will retransmit it.
Reachable time After the neighbor reachability detection shows that a neighbor is
reachable, the device considers the neighbor is reachable within the
reachable time. If the device needs to send a packet to a neighbor after the
reachable time expires, the device will again confirm whether the neighbor
is reachable.
The values of the Retrans Timer field and the Reachable Time field configured for
an interface are sent to hosts via RA messages. Furthermore, this interface sends
NS messages at intervals of Retrans Timer and considers a neighbor reachable
within the time of Reachable Time.
Use the command...
system-view
interface interface-type
interface-number
ipv6 neighbors
max-learning-num number
Configuring IPv6 NDP 511
Remarks
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-
Optional