VoIP VLAN on Packet Tracer: phones don't recieve IPs

[Nestor_Te]

Hi all!

I'm not an IT guy, I'm taking the first steps, learning the Cisco system for myself, and from time to time I have questions that are probably a little stupid, but I can't find answers in the documentation or Internet.
I compose a network in Packet Tracer of 2811 router, 2960 switch and three 7960 phones. When I start telephony service, the phones are assigned numbers and everything works. But if I make the same settings not on VLAN 1, but make a separate VLAN and do same configuration there, phones cannot receive an IP addresses, although the configs differ only in the VLAN number. What did I forget to do? What else needs to be configured to move the phones to a separate VLAN?

[balaji.bandi]

when you change the VLAN the Interface VLAN need to mention where the DHCP Server

interface vlan X

ip helper-address x.x.x.x  (dhcp Server to get DHCP IP)

[Nestor_Te]

Thank you for answer! I did that but my phones still indicates "Configuring IP" messages.

For a better understanding of problem I'll show my configs, maybe I miss something

Spoiler

Router#sh run

Building configuration...

Current configuration : 1004 bytes

!

version 15.1

no service timestamps log datetime msec

no service timestamps debug datetime msec

no service password-encryption

!

hostname Router

!

!

!

!

ip dhcp excluded-address 172.16.0.1

!

ip dhcp pool Phones

network 172.16.0.0 255.255.255.0

default-router 172.16.0.1

option 150 ip 172.16.0.1

!

!

!

ip cef

no ipv6 cef

!

!

!

!

license udi pid CISCO2811/K9 sn FTX1017946S-

!

!

!

!

!

!

!

!

!

!

!

spanning-tree mode pvst

!

!

!

!

!

!

interface FastEthernet0/0

ip address 172.16.0.1 255.255.255.0

duplex auto

speed auto

!

interface FastEthernet0/1

no ip address

duplex auto

speed auto

shutdown

!

interface Vlan1

no ip address

shutdown

!

interface Vlan10

mac-address 0060.70c7.a901

no ip address

ip helper-address 172.16.0.1

!

ip classless

!

ip flow-export version 9

!

!

!

!

!

!

!

telephony-service

max-ephones 4

max-dn 4

ip source-address 172.16.0.1 port 2000

auto assign 1 to 4

!

ephone-dn 1

number 11

!

ephone-dn 2

number 12

!

line con 0

!

line aux 0

!

line vty 0 4

login

!

!

!

end

Spoiler

Switch#sh run

Building configuration...

Current configuration : 1222 bytes

!

version 15.0

no service timestamps log datetime msec

no service timestamps debug datetime msec

no service password-encryption

!

hostname Switch

!

!

!

!

!

!

spanning-tree mode pvst

spanning-tree extend system-id

!

interface FastEthernet0/1

switchport voice vlan 10

!

interface FastEthernet0/2

switchport voice vlan 10

!

interface FastEthernet0/3

!

interface FastEthernet0/4

!

interface FastEthernet0/5

!

interface FastEthernet0/6

!

interface FastEthernet0/7

!

interface FastEthernet0/8

!

interface FastEthernet0/9

!

interface FastEthernet0/10

!

interface FastEthernet0/11

!

interface FastEthernet0/12

!

interface FastEthernet0/13

!

interface FastEthernet0/14

!

interface FastEthernet0/15

!

interface FastEthernet0/16

!

interface FastEthernet0/17

!

interface FastEthernet0/18

!

interface FastEthernet0/19

!

interface FastEthernet0/20

!

interface FastEthernet0/21

!

interface FastEthernet0/22

!

interface FastEthernet0/23

!

interface FastEthernet0/24

switchport voice vlan 10

!

interface GigabitEthernet0/1

!

interface GigabitEthernet0/2

!

interface Vlan1

no ip address

shutdown

!

interface Vlan10

no ip address

ip helper-address 172.16.0.1

!

!

!

!

line con 0

!

line vty 0 4

login

line vty 5 15

login

!

!

!

!

end

[Martin L]

you attach your PT file here in a zip format so that we can check it out; 

Regards, ML
**Please Rate All Helpful Responses **

[Nestor_Te]

Of course, that is my file. Thank you!

[Martin L · Accepted solution]

yes, i see issue; maybe PT does not support other configs 

see https://learningnetwork.cisco.com/s/question/0D53i00000KsnLrCAJ/vlan-question-how-do-nodes-automatically-find-a-vlan-on-a-cisco-switch

no need for ip helper-address 172.16.0.1 anywhere in your lab. 

Regards, ML
**Please Rate All Helpful Responses **

[Nestor_Te]

Thank you very much for the answer!
So, if I understood correctly, on real switches and routers it is possible to set up a separate voice VLAN, but in PT the functionality is limited, so it is impossible to do this?

Upd. I changed VLAN 10 to 1 and everything worked. It's probably really a limitation of the program.

[Martin L]

yes, real switch has 4 ways to configure that special voice " mini-trunk " port as u see in CLN post, (note: attached picture shows only 2 connections).  I guess PT developers have not worked out such options.  What works or not in PT should be displayed under PT Help menu, 

Real switch voice port options should be 

switchport voice vlan {vlan-id | dot1p | untagged | none}

Regards, ML
**Please Rate All Helpful Responses **

[Martin L · Accepted solution]

here is good explanation 

https://www.learncisco.net/courses/icomm-ccna-voice/cisco-uc-solution-maintenance/switch-configuration.html