HP A5120 Switch | DHCP Relay

How to configure DHCP Relay on a HP A5120 switch.
To do this you need to go in the system-view of the switch. As followed you need to configured the DHCP Option in the switch. You can do this by:

 #
 dhcp enable
 #

Now you need to configure a Server-group where you configure the DHCP server where the clients can find their addresses.

 #
 dhcp relay server-group 0 ip <server ip address>
 #

Configure some vlans if you don’t have some.

#
vlan 1
 igmp-snooping enable
#
vlan 2
 name Wi-Fi
#
vlan 3
 name Management
#
interface Vlan-interface1
 ip address xxx.xxx.xx1.249 255.255.255.0
#
interface Vlan-interface2
 ip address xxx.xxx.xx2.249 255.255.255.0

You need to specify the following commands to enable the dhcp relay on the vlan interface.

 dhcp select relay
 dhcp relay server-select 0

After this you can configure your DHCP server with the correct addresses for the created vlan. Which should archive an IP address from the server.

2 Comments on "HP A5120 Switch | DHCP Relay"


  1. Let say i have 2 DHCP servers which i will used for 2 subnets in the same vlan
    dhcp relay server-group 3 ip a.a.a.a
    dhcp relay server-group 4 ip b.b.b.b
    My current config for the existing subnet as below:-
    interface Vlan-interface101
    description OFFICE
    ip address x.x.x.1 255.255.255.0
    ospf cost 10
    dhcp select relay
    dhcp relay server-select 4
    igmp enable
    igmp version 3
    pim sm
    so my plan is to add new subnet y.y.y.0/24 in the same vlan 101 but it will lease ip from server group 3.
    Is this possible? and do you have any idea how my config should looks like.

    Reply

    1. For as I know this isn’t possible you should create a new vlan. You can only have 1 DHCP server on a subnet.
      if you are creating a new domain in the same subnet you can install this but you have to transfer the DHCP role to a new server in the new domain. I hope this helps.

      Reply

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