3Com MSR 50 Series Configuration Manual page 668

668 C 46: IP 6 B
HAPTER V ASICS
n
C
ONFIGURATION
Table 39 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 information After receiving the prefix information advertised by the device, the
options hosts on the same link can perform stateless autoconfiguration
operations.
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 (for example, through a DHCP server).
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 to
acquire information other than IPv6 addresses (for example, through a
DHCP server). 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.
Retrans timer If the device fails to receive a response message within the specified
time after sending an NS message, the device will retransmit the NS
message.
Reachable time If the neighbor reachability detection shows that a neighbor is
reachable, the device considers the neighbor is reachable within the
specified reachable time. If the device needs to send a packet to a
neighbor after the specified reachable time expires, the device will
reconfirm 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.
Follow these steps to configure parameters related to an RA message:
To do...
Enter system view
Configure the current
hop limit
Enter interface view
Disable the RA message
suppression
Use the command...
system-view
ipv6 nd hop-limit value
interface interface-type
interface-number
undo ipv6 nd ra halt
Remarks
-
Optional
64 by default.
-
Optional
By default, RA messages are
suppressed.