Dhcpv4 Relay Agent Information - ZyXEL Communications GS1350 Series User Manual

31.4.1 DHC Pv4 Re la y Ag e nt Info rm a tio n
The Switch can add information about the source of client DHCP requests that it relays to a DHCP server
by adding
Re la y Ag e nt Info rm a tio n
The DHCP server can then provide an IP address based on this information. Please refer to RFC 3046 for
more details.
The DHCP
Re la y Ag e nt Info rm a tio n
field) to DHCP requests. The
82
the Switch relays to a DHCP server.
Re la y Ag e nt Info rm a tio n
change the
The following describes the DHCP relay agent information that the Switch sends to the DHCP server:
Table 113 Relay Agent Information
FIEL D L ABEL S
Slot ID
Port ID
VLAN ID
Information
31.4.1.1 DHC Pv4 Re la y Ag e nt Info rm a tio n Fo rm a t
A DHCP Relay Agent Information option has the following format.
Table 114 DHCP Relay Agent Information Option Format
Code
(82)
i1, i2 and iN are DHCP relay agent sub-options, which contain additional information about the DHCP
client. You need to define at least one sub-option.
31.4.1.2 Sub - O ptio n Fo rm a t
There are 2 types of sub-option: "Agent Circuit ID Sub-option" and "Agent Remote ID Sub-option". They
have the following formats.
Table 115 DHCP Relay Agent Circuit ID Sub-option Format
SubOpt Code
1
(1 byte)
Table 116 DHCP Relay Agent Remote ID Sub-option Format
SubOpt Code
2
(1 byte)
The 1 in the first field identifies this as an Agent Circuit ID sub-option and two identifies this as an Agent
Remote ID sub-option. The next field specifies the length of the field.
. This helps provide authentication about the source of the requests.
feature adds an Agent Information field (also known as the
O ptio n 82
can include the
in
Syste m Na m e Ba sic Se tting s
DESC RIPT IO N
(1 byte) This value is always 0 for stand-alone switches.
(1 byte) This is the port that the DHCP client is connected to.
(2 bytes) This is the VLAN that the port belongs to.
(up to 64 bytes) This optional, read-only field is set according to system name set in
>
Se tting s G e ne ra l Se tup
Length i1
(N)
Length
N Slot ID, Port ID, VLAN ID, System Name or String
(1 byte)
Length
N MAC Address or String
(1 byte)
GS1350 Series User's Guide
Chapter 31 DHCP
field is in the DHCP headers of client DHCP request frames that
of the Switch if you select this option. You can
Syste m Na m e
> .
G e ne ra l Se tup
.
i2
...
Value
Value
243
iN
O ptio n
Ba sic