3com S7906E 설치 설명서

 

1-14 

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: 

Enter 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 

 

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. 

 lists the configurable parameters in an RA message and 

their descriptions. 

Table 1-4 Parameters in an RA message and their descriptions 

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.