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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 in 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
, Interface A with IPv6 address 4:1::96/64 and Interface B with IPv6 address
4:2::99/64 belong to different subnets. Host A and Host reside on the same network but in different
broadcast domains.
Figure 7 Application environment of common 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 Interface A and Interface B of the Device. The
Device replies to the NS message from Host A, and forwards packets from other hosts to Host B.
Local ND proxy
As shown in
, Host A belongs to VLAN 2 and Host B belongs to VLAN 3. Host A and Host B
connect to Interface A and Interface C, respectively.
Figure 8 Application environment of local 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 are in different VLANs.
To solve this problem, enable local ND proxy on Interface B of the router so that the router can
forward messages between Host A and Host B.