HP 5120 DHCP Issue

[ATAHER]

Dear All ,

we have one core Switch 7506 and seven 5120 Switch all are connected to the core switch using Fiber connection .

also we have one avaya IP office connected to the Core Switch.

we have configured two vlans " DATA & VOICE ",

VLAN 20
name DATA
!
VLAN 30
name VOICE

and we have one DHCP Sever 2008 R2 connect to the core SWitch and the port is untagged to DATA VLAN " vlan 20 "

and using for one scope for Users, and we have  configured the relay as below:;

dhcp enable
dhcp relay server-group 1 ip 172.16.0.20
interface Vlan-Interface 20
dhcp select relay
dhcp relay server-select 1

and we are using AVAYA IP office to send  DHCP to IP Phones:

dhcp relay server-group 2 ip 192.168.42.9
interface Vlan-Interface 30
dhcp select relay
dhcp relay server-select 2

but all IP Phones not taking IP address, and DATA can take, but if i configure one port untegged to VLAN 30 and PVID is 30 , it take IP Address from DATA VLAN.

[manuel.bitzi]

Please post the interface config where the phones and pc's are connected.

br

Manuel

[ATAHER]

Dear Manuel,

this is the config of one interface:

interface GigabitEthernet1/0/2
port link-type hybrid
undo port hybrid vlan 1
port hybrid vlan 20 untagged
port hybrid pvid vlan 20
voice vlan 30 enable
poe enable

[Vince-Whirlwind]

...please also show us the config on each of your VLAN interfaces - ie, there should be IP addressing on each of them.

[ATAHER]

please check below :

#
interface Vlan-interface20
 ip address 172.16.0.5 255.255.0.0
 dhcp select relay
 dhcp relay server-select 1
 dhcp relay information enable
#
interface Vlan-interface30
 ip address 192.168.42.5 255.255.255.0
 dhcp select relay
 dhcp relay server-select 2
 dhcp relay information enable

also what i did, i have removed default OUI and added OUI for AVAYA IP Phones.

what happened after that, there is some phones take correct IP addresses from Voice VLAN but alot of IP Phones not taking any IP Address

[Vince-Whirlwind]

I don't understand why you have DHCP relay config in there - you seem to have a DHCP server on each Layer2 segment.

DHCP relay is for when your DHCP server is *not* on the Layer2 segment that needs its service.

Additionally, DHCP relay on these devices does A LOT more than just relay the broadcast packet. It's very very painful of all you want is DHCP relay, because it does all sorts of other stuff that can break things for you until you figure out what it is doing.

[ATAHER]

please note the below and help to correct the config:

1- we have VLAN 20 " 172.16.0.0." it take DHCP from Windows server 2008 " 172.16.0.20"

so inform me what configuration should i remove from interface VLAN, and what i need to add.

2- Voice VLAN "192.168.42.0" it take DHCP from AVAYA system " 192.168.42.9"

also please inform what shall i do " add , remove" to corrct the config.

[Vince-Whirlwind]

How does DHCP work?

Think about how the DHCP request is going to reach the server.

Do you think you need a DHCP relay?