ZyXEL Communications GS2210-24, Руководство пользователя

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Chapter 40 DHCP
GS2210 Series User’s Guide
339
The Sw it ch can be configur ed as a global DHCP r elay. This m eans t hat t he Swit ch for war ds all DHCP
r equest s fr om all dom ains t o t he sam e DHCP ser ver. You can also configur e t he Swit ch t o r elay
DHCP infor m at ion based on t he VLAN m em ber ship of t he DHCP client s.
40.4.1 DHCPv4 Relay Agent Information
The Swit ch can add infor m at ion about t he sour ce of client DHCP r equest s t hat it r elays t o a DHCP
ser ver by adding Re la y Age n t I n f or m a t ion . This helps pr ov ide aut hent icat ion about t he source of
t he request s. The DHCP server can t hen pr ov ide an I P addr ess based on t his infor m at ion. Please
r efer t o RFC 3046 for m or e det ails.
The DHCP Re la y Age n t I n for m a t ion feat ur e adds an Agent I nfor m at ion field ( also know n as t he
Opt ion 8 2 field) t o DHCP r equest s. The Opt ion 8 2 field is in t he DHCP header s of client DHCP
r equest fram es t hat t he Swit ch r elays t o a DHCP ser ver.
Re la y Age n t I n for m a t ion can include t he Sy st e m N a m e of t he Sw it ch if you select t his opt ion.
You can change t he Sy st e m N a m e in Ba sic Se t t in gs > Ge n e r a l Se t u p.
The follow ing descr ibes t he DHCP r elay agent infor m at ion t hat t he Swit ch sends t o t he DHCP
ser ver :
40.4.1.1 DHCPv4 Relay Agent Information Format
A DHCP Relay Agent I nfor m at ion opt ion has t he follow ing for m at .
i1, i2 and iN ar e DHCP r elay agent sub- opt ions, w hich cont ain addit ional infor m at ion about t he
DHCP client . You need t o define at least one sub- opt ion.
40.4.1.2 Sub-Option Format
Ther e ar e t w o t ypes of sub- opt ion: “Agent Cir cuit I D Sub- opt ion” and “Agent Rem ot e I D Sub-
opt ion”. They have t he following for m at s.
Table 165 Relay Agent I nfor m at ion
FIELD LABELS DESCRIPTION
Slot I D ( 1 by t e) This value is alway s 0 for st and- alone sw it ches.
Port I D ( 1 by t e) This is t he por t t hat t he DHCP client is connect ed t o.
VLAN I D ( 2 by t es) This is t he VLAN t hat t he por t belongs t o.
I nfor m at ion ( up t o 64 by t es) This opt ional, r ead- only field is set accor ding t o sy st em nam e set in
Ba sic Se t t in gs > Ge n e r a l Se t u p.
Table 166 DHCP Relay Agent I nfor m at ion Opt ion For m at
Code
( 82)
Lengt h
( N)
i1 i2
...
iN
Table 167 DHCP Relay Agent Cir cuit I D Sub- opt ion Form at
SubOpt Code Lengt h Value
1
( 1 by t e)
N
( 1 by t e)
Slot I D, Por t I D, VLAN I D, Sy st em Nam e or St r ing