R0106-HP MSR Router Series Layer 3 - IP Services Configuration Guide(V7)

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message again. If the interface still does not receive a response after the number of attempts reaches the
threshold specified by the ipv6 nd dad attempts command, it considers the address is usable.
To configure the attempts to send an NS message for DAD:
Ste
p
Command Remarks
1. Enter system view.
system-view N/A
2. Enter interface view.
interface interface-type
interface-number
N/A
3. Configure the number of
attempts to send an NS
message for DAD.
ipv6 nd dad attempts value
The default setting is 1. When the value
argument is set to 0, DAD is disabled.
Enabling ND proxy
About ND proxy
ND proxy enables a device to answer an NS message requesting the hardware address of a host on
another network. With ND proxy, hosts on different broadcast domains can communicate with each
other as they would on the same network.
ND proxy includes common ND proxy and local ND proxy.
• Common ND proxy
As shown in Figure 79, GigabitEthernet 1/0/1 with IPv6
address 4:1::99/64 and
GigabitEthernet 1/0/2 with IPv6 address 4:2::99/64 belong to different subnets. Host A and
Host B reside on the same network but in different broadcast domains.
Figure 79 Application environment of ND proxy
Because Host A's IPv6 address is on the same subnet as Host B's, Host A directly sends an NS
message to obtain Host B's MAC address. However, Host B cannot receive the NS message
because they belong to different broadcast domains.
To solve this problem, enable common ND proxy on GigabitEthernet 1/0/1 and GigabitEthernet
1/0/2 of the router. The router replies to the NS message from Host A, and forwards packets from
other hosts to Host B.
• Local ND proxy
As shown in Figure 80, both Host A and Host B belong to VLAN 2. Howeve
r, they connect to
GigabitEthernet 1/0/3 and GigabitEthernet 1/0/1 respectively, which are isolated at Layer 2.