ZyXEL Communications OLT2406, User Manual

Page: 591 / 766

Chapter 82 DHCP
OLT2406 User’s Guide
591
The OLT can be configured as a global DHCP relay. This means that the OLT forwards all DHCP requests
from all domains to the same DHCP server. You can also configure the OLT to relay DHCP information
based on the VLAN membership of the DHCP clients.
82.2.1 DHCP Relay Agent Information
The OLT can add information about the source of client DHCP requests that it relays to a DHCP server by
adding
Relay Agent Information . This helps provide authentication about the source of the requests. The
DHCP server can then provide an IP address based on this information. Please refer to RFC 3046 for more
details.
The DHCP Relay Agent Information feature adds an Agent Information field to the Option 82 field. The
Option 82 field is in the DHCP headers of client DHCP request frames that the OLT relays to a DHCP
server.
Relay Agent Information can include the system name of the OLT. See Section 54.2 on page 413 for how
to change the system name.
The following describes the DHCP relay information that the OLT sends to the DHCP server:
82.3 DHCP Commands
Use these commands to configure DHCP features on the OLT.
• Use the
dhcp relay
commands to configure DHCP relay for specific VLAN.
• Use the
dhcp smart-relay
commands to configure DHCP relay for all broadcast domains.
• Use the
dhcp server
commands to configure the OLT as a DHCP server. (This command is available
on a layer 3 switch only.)
Table 305 Relay Agent Information
FIELD LABELS DESCRIPTION
Slot ID (1 byte) This is the slot that the DHCP client is connected to.
Port ID (1 byte) This is the port that the DHCP client is connected to.
VLAN ID (2 bytes) This is the VLAN that the port belongs to.
Information (up to 64 bytes) This optional, read-only field is set according to system name set
in
Basic Settings > General Setup.
Table 306 DHCP Server Commands
COMMAND DESCRIPTION M P
dhcp server < vlan-id > starting-
address < ip-addr > < subnet-mask >
size-of-client-ip-pool <1-2048>
[default-gateway < ip-addr >]
[primary-dns < ip-addr >]
[secondary-dns < ip-addr >]
Enables DHCP server for the specified VLAN and
specifies the TCP/IP configuration to send to
DHCP clients. You can optionally include a
default gateway IP address and DNS server
addresses. C 13
no dhcp server < vlan-id >
Disables DHCP server configuration for the
specified VLAN. C 13