Vivotek AW-IHT-1270, Руководство пользователя

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Parameter Description
Name Configures the selective Q-in-Q profile name.
Access Ports Configures a port or a range of ports for the access ports.
Tunnel Ports Configures a port or a range of ports for the tunnel ports.
CVID Configures a customer’s VLAN.
SPVID Configures a service provider’s VLAN.
Priority Configures an 802.1Q priority for the profile.
Action Enables / Disables the profile.
6.4. DHCP Option 82
6.4.1. Introduction
DHCP Option 82 is the “DHCP Relay Agent Information Option”. Option 82 was designed to
allow a DHCP Relay Agent to insert circuit specific information into a request that is being
forwarded to a DHCP server. Specifically the option works by setting two sub-options: Circuit
ID and Remote ID.
The DHCP option 82 is working on the DHCP snooping or/and DHCP relay.
The switch will monitor the DHCP packets and append some information as below to the
DHCPDISCOVER and DHCPREQUEST packets. The switch will remove the DHCP Option 82
from the DHCPOFFER and DHCPACK packets. The DHCP server will assign IP domain to the
client dependent on these information.
The maximum length of the information is 32 characters.
In residential, metropolitan Ethernet-access environments, DHCP can centrally manage the IP
address assignments for a large number of subscribers. When the DHCP option-82 feature is
enabled on the switch, a subscriber device is identified by the switch port through which it
connects to the network (in addition to its MAC address). Multiple hosts on the subscriber LAN
can be connected to the same port on the access switch and are uniquely identified.
When you enable the DHCP snooping information option 82 on the switch, this sequence of
events occurs:

The host (DHCP client) generates a DHCP request and broadcasts it on the network.

When the switch receives the DHCP request, it adds the option-82 information in the packet.
The option-82 information contains the switch MAC address (the remote-ID suboption) and
the port identifier, vlan-mod-port, from which the packet is received (the circuit-ID
suboption).

If the IP address of the relay agent is configured, the switch adds the IP address in the DHCP
packet.