No able to get IP for IP Phone through DHCP from Layer 3 Switch

[feruqhshariff]

Have configured 3 VLAN's.

1) Desktop & Laptop

2) IP Phone

3) Server's

DHCP is configured and ip is getting released to desktop & server's,  However not getting IP's to VOIP phone. which is in seperate VLAN. Attached is n/w diagram.

Please suggest

[pkumari4]

Hello Shariff,

I believe that you have created separate VLAN for data and voice traffic.

All the IP phones are facing the issue or specific one?

++If all IP phones have the same issue then please remove the phone and try to connect a laptop ,  see if you are getting the IP address from voice VLAN after connecting a laptop.

++If you are facing issue with a specific port for voice traffic then please bounce the port and check

Please share the port and the VLAN configuration for both voice and data.

Regards,

Priyanka

[feruqhshariff]

Thanks for the reply... I connected the laptop to the voice vlan but the laptop also couldn't get the ip it is getting APIPA.

Find attached the running-config of the switch. 

Please suggest, 

Also please note i am doing this for the first time as i am eager to learn this (VLAN)

[pkumari4 · Accepted solution]

Hello Sheriff,

If your laptop is getting the APIPA IP it means there is something wrong with the configuration. 

I quickly checked the attached configuration and found that there is misconfiguration for voice VLAN that is 20.

Please make sure that you have created the VLAN for both data and voice using below command:

Creating VLAN's

Voice VLAN

Switch#conf t

Switch(config)#vlan <VLAN ID>

Switch(config-vlan)#name Voice - description of the VLAN

Similarly for the Data VLAN

Switch#conf t

Switch(config)#vlan <VLAN ID>

Switch(config-vlan)#name Data - description of the VLAN

Interface configuration - Data/Voice

Switch#conf t

Switch(config)#interface GigabitEthernet <interface ID>

Switch(config-if)#switchport mode access

Switch(config-if)#switchport access vlan <VLAN ID> - data VLAN in case of PC

or

Switch(config-if)#switchport voice vlan <VLAN ID> - Voice VLAN in case of phone

Use the below config for your gig port and share the outcome.

Before executing the below command make sure you have named VLAN 20 as a voice VLAN to avoid the confusion.

interface GigabitEthernet1/0/15
switchport mode access
 switchport voice vlan 20
 switchport nonegotiate
 

Regards,

Priyanka

[feruqhshariff]

Hi,

Can you also please share DHCP Configuration commands

[feruqhshariff]

Hi,

I reconfigured the entire switch now iam able to get dhcp IP's in all the vlan's.

"However now i noticed that i would not be able to connect any other device except ip phone's in voice vlan"  and cannot communicate from other vlan to voice vlan

Also noticed that ports of voice vlan also remain in default vlan1 is it fine?

Is the above valid ?

Can i give bandwidth restriction for voice vlan ?.

Attache is the configuration details, please validate and confirm.

@pkumari4 

@omz 

[pkumari4]

Hello Shariff,

Please be noted that at present you have configured only voice VLAN on the port, The voice VLAN feature enables access ports to carry IP voice traffic from an IP phone.

So if you want to use both voice and data traffic on the same port then please use the below config. I have added this line in the config SW1(config-if-range)#switchport access vlan 40

SW1(config)#interface range gigabitEthernet1/0/13 – 20

SW1(config-if-range)#switchport mode access
SW1(config-if-range)#switchport nonegotiate
SW1(config-if-range)#switchport voice vlan 30
SW1(config-if-range)#switchport access vlan 40
SW1(config-if-range)#do wr mem

on the port. I believe vlan 40 is your fdata vlan.

Also, noticed that ports of voice VLAN also remain in default vlan1 is it fine?

Yes, it's totally fine. By default VLAN 1 is the native VLAN on the cisco switch.

Regards,

Priyanka

[feruqhshariff]

Thank You !

Can you please share about bandwidth utilization restriction on vlan's.

[omz]

hi

what is the model of the switch?

have a look at some of the examples here - 

https://www.cisco.com/c/en/us/support/docs/switches/catalyst-3750-series-switches/91862-cat3750-qos-config.html

[feruqhshariff]

Cisco 9200L 48 port switch

[omz]

you can look at configuring auto-qos.. then you don't have to write a qos policy yourself. Depends how comfortable you are with qos. have a look at auto-qos for voip phone in this document - 

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst9200/software/release/16-10/configuration_guide/qos/b_1610_qos_9200_cg.pdf

[omz · Accepted solution]

interface GigabitEthernet1/0/14
 switchport access vlan 20 <<< remove this command if using voice vlan 20
 switchport mode access
 switchport nonegotiate
 switchport voice vlan 20 <<< this is enough for voice vlan

https://community.cisco.com/t5/networking-documents/sample-configuration-for-voice-and-data-deployment-on-a-switch/ta-p/3123513

option 150 ip x.x.x.x 

this command is used to define the IP address(es) of the TFTP server(s) (CME/CUCM) to download the phone configuration files.

your DHCP config looks ok

ip dhcp excluded-address 10.178.5.1 10.178.5.10
Host Address Range 10.178.5.1 - 10.178.5.126

ip dhcp excluded-address 10.178.5.129 10.178.5.131
Host Address Range 10.178.5.129 - 10.178.5.190

ip dhcp excluded-address 10.178.5.193 10.178.5.195
Host Address Range 10.178.5.193 - 10.178.5.254