36
the
Reload
button
to
refresh
the
listing.
DHCP
Relay
Agent
You
can
select
to
Enable
or
Disable
DHCP
relay
agent
function,
and
then
select
the
modification
type
of
option
82
field.
Relay
policy
drop
:
Drops
the
option
82
field
and
do
not
add
any
option
82
field.
Relay
policy
keep
:
Keeps
the
original
option
82
field
and
forwards
to
server.
Relay
policy
replace
:
Replaces
the
existing
option
82
field
and
adds
new
option
82
field.
(This
is
the
default
setting)
Helper
Address:
there
are
4
fields
for
the
DHCP
server’s
IP
address.
You
can
filll
the
field
with
prefered
IP
address
of
DHCP
Server,
and
then
click
“Apply”
to
activate
the
DHCP
relay
agent
function.
All
the
DHCP
packets
from
client
will
be
modified
by
the
policy
and
forwarded
to
DHCP
server
through
the
gateway
port.
4.2.6
Backup
and
Restore
With
Backup
command,
you
can
save
current
configuration
file
saved
in
the
switch’s
flash
to
admin
PC
or
TFTP
server.
This
will
allow
you
to
go
to
Restore
command
later
to
restore
the
configuration
file
back
to
the
switch.
Before
you
restore
the
configuration
file,
you
must
place
the
backup
configuration
file
in
the
PC
or
TFTP
server.
The
switch
will
then
download
this
file
back
to
the
flash.
There
are
2
modes
for
users
to
backup/restore
the
configuration
file,
Local
File
mode
and
TFTP
Server
mode.
Local
File
mode:
In
this
mode,
the
switch
acts
as
the
file
server.
Users
can
browse
the
target
folder
and
then
type
the
file
name
to
backup
the
configuration.
Users
