3Com S7906E - Switch, Руководство по настройке

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1-14
Configuring the Maximum Number of Neighbors Dynamically Learned
The device can dynamically acquire the link-layer address of a neighbor node through NS and NA
messages and add it into the neighbor table. Too large a neighbor table may reduce the forwarding
performance of the device. You can restrict the size of the neighbor table by setting the maximum
number of neighbors that an interface can dynamically learn. When the number of dynamically learned
neighbors reaches the threshold, the interface will stop learning neighbor information.
Follow these steps to configure the maximum number of neighbors dynamically learned:
To do… Use the command… Remarks
Enter system view system-view —
Enter interface view
interface interface-type
interface-number
—
Configure the maximum
number of neighbors
dynamically learned by an
interface
ipv6 neighbors
max-learning-num number
Optional
2048 by default
Configuring Parameters Related to RA Messages
You can enable an interface to send RA messages, and configure 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 1-4 lists the configurable parameters in an RA message and
their descriptions.
Table 1-4 Parameters in an RA message and their descriptions
Parameters Description
Cur hop limit
When sending an IPv6 packet, a host uses the value to fill the Cur Hop Limit
field in IPv6 headers. The value is also filled into the Cur Hop Limit field in
response messages of a device.
Prefix information
options After receiving the prefix information advertised by the device, the hosts on
the same link can perform stateless autoconfiguration.
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 (for
example, through a DHCP server) to acquire IPv6 addresses. Otherwise,
hosts use the stateless autoconfiguration to acquire IPv6 addresses, that
is, hosts generate 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, through a 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.