SGS-6341-Series User Manual

1. Enable DHCP relay.
Command Explanation
Global Mode
service dhcp
no service dhcp
DHCP server and DHCP relay is enabled as the
DHCP service is enabled.
2. Configure DHCP relay to forward DHCP broadcast packet.
Command Explanation
Global Mode
ip forward-protocol udp bootps
no ip forward-protocol udp bootps
The UDP port 67 is used for DHCP broadcast
packet forwarding.
VLAN Interface Mode
ip helper-address <ipaddress>
no ip helper-address <ipaddress>
Set the destination IP address for DHCP relay
forwarding; the “no ip helper-address
<ipaddress>“command cancels the setting.
3. Configure share-VLAN
When the user want to use layer 2 device as DHCP relay, there is the number limitation that
create layer 3 interface on layer 2 device, but using the layer 3 interface of share-VLAN (it may
include many sub-VLAN, however a sub-VLAN only correspond to a share-VLAN) can
implement DHCP relay forwarding, and the relay device needs to enable option82 function at
the same time.
Command Explanation
Global Mode
ip dhcp relay share-vlan <vlanid>
sub-vlan <vlanlist>
no dhcp relay share-vlan
Create or delete share-VLAN and it's sub-VLAN.
31.4 DHCP Configuration Examples
Scenario 1:
Too save configuration efforts of network administrators and users, a company is using switch
as a DHCP server. The Admin VLAN IP address is 10.16.1.2/16. The local area network for the
company is divided into network A and B according to the office locations. The network
configurations for location A and B are shown below.
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User’s Manual of SGS-6341 series