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DHCP assignment problem

Yan Henrichon
Frequent Advisor

DHCP assignment problem

Hi.
We have VoIP and Data vlans. The DHCP scopes are created on the Windows Server. IP helper is activated on the core switches (routing enabled). VoIP vlans are tagged and data vlan are untagged on each specified ports. When I boot my phone, it receives the IP address of the Data vlan scope.

See attachment to look at part of the config of both core and edge switches. Do not rely on the port tagging/untagging provided with the config files. Look at the Vlan config if you see anormal or missing information.

Thank you very much for your precious help.
5 REPLIES
cenk sasmaztin
Honored Contributor

Re: DHCP assignment problem

hi Yan I make new config for you
please test

cenk
------------------------------------------------------------
CORE CONFIGURATION
------------------------------------------------------------
ip routing
vlan 1
name "Servers"
untagged 7-9,21-50 *****************(connect dhcp server untag port)(50 uplink port connect other switch vlan 100 must be untag memberon port 50)
no untagged 1-6,10-20
ip address 172.16.10.251 255.255.0.0
exit
vlan 80
name "TEL"
untagged 1-5**********************(this ports connect comminication server and/or direct ip tel.)
ip helper-address 172.16.10.16
ip address 10.80.0.254 255.255.0.0
tagged 6-50***********************(tagged 6-50 ports ,because you want connect ip tel. under pc connection)
voice
ip igmp
exit
vlan 120
name "Postes_Admin"
ip helper-address 172.16.10.16
ip address 10.120.0.254 255.255.0.0
untagged 10-20
tagged 50
ip igmp
exit
vlan 130
name managemetvlan
ip address 10.0.0.1 255.255.255.0
untag 6*******(for admin connection)********************
tagged 50
managemet vlan-130
ip route 0.0.0.0 0.0.0.0 172.16.10.254

------------------------------------------------------------
EDGE CONFIGURATION
------------------------------------------------------------

vlan 1
name "Servers"
untagged 9-11,50
no untagged 1-8
ip igmp
exit
vlan 80
name "TEL"
qos priority 6
untag 1-8 **********************(this ports connect direct ip tel.)
tagged 9-50 ***********************(tagged 6-50 ports ,because you want connect ip tel. under pc connection)
voice
exit
vlan 120
name "Postes_Admin"
untagged 12-49
tagged 50
ip igmp
exit
vlan 130
name managemetvlan
ip address 10.0.0.2 255.255.255.0
tagged 50
management vlan-130




dhcp server config
**************************************************************
dhcp server nic config
ip address 172.16.10.16
subnet mask 255.255.0.0
default gateway 172.16.10.251

***************************************************************
dhcp scobe config

scobe name vlan80
ip pool 10.80.0.10......200
subnet mask 255.255.0.0
default gateway 10.0.80.254

scobe name vlan120
ip pool 10.120.0.10......200
subnet mask 255.255.0.0
default gateway 10.120.0.254
***************************************************************

****************************************************************
ip tel config
you want ip tel.under pc connection you can must be config vlan id on ip tel.
and connect ip tel.vlan80 tag port on switch after connect pc on ip tel.

you want connect ip tel direc switch connect untag port vlan 80 direc ip tel
cenk

Yan Henrichon
Frequent Advisor

Re: DHCP assignment problem

Thank You Cenk for replying this fast. I've been reading this forum for a while now and let me say something: you're a machine. :)

OK, now let's get serious.

I forgot to tell you that the vlan 100 "Servers" is also my management vlan. The switches, servers and AP's are in that vlan.

The DHCP scopes are as you described.

What I understand is the phone is connected to the switch port which is tagged vlan 80 "TEL" and the pc is peggy-backed in the phone and the switch port is untagged vlan 120 "Postes_Admin".

I'm I right?

Thx.
cenk sasmaztin
Honored Contributor

Re: DHCP assignment problem

I forgot to tell you that the vlan 100 "Servers" is also my management vlan. The switches, servers and AP's are in that vlan.

hi Yan
managemet vlan must be special vlan (different vlan)
not connect server or user managemet vlan for security
and you make write managemet-vlan command on switch

(config)#managemet-vlan 130
you can write managemet vlan command on switch
do not routing managemet vlan
only connect netwrok analaizer and managemet pc this vlan




What I understand is the phone is connected to the switch port which is tagged vlan 80 "TEL" and the pc is peggy-backed in the phone and the switch port is untagged vlan 120 "Postes_Admin".


yes you can understand me true
please look attachmend


cenk
cenk

Yan Henrichon
Frequent Advisor

Re: DHCP assignment problem

Is the fact that I put all the servers and swithches in the same VLAN cause me this unique problem?
Yan Henrichon
Frequent Advisor

Re: DHCP assignment problem

Finally, our configuration was fine. We have passed the VLAN ID to the phone that belongs to that vlan and now everything works like a charm.