Vlan Tagging Problem?

[Ahdinko]

Hello all.

Have a strange problem with our phones and Vlans.

We have a Mitel 3300 controller and Mitel 5220's and 5224's as our phones. The controller acts as the DHCP server for the phones.

We are using a Cisco 2950 as our switch. The Mitel 3300 connects into the cisco 2950, as well as a data switch and WAN link

We want to replace the Cisco 2950 with a 3560 as it has double the amount of ports, and POE (We are using a PowerDzine to inject power for phones currently)

So last weekend, I configured the new Cisco 3560 to match the config on the 2950. I replace the 2950 with the new 3560, the phones get power, get the first DHCP address, release it, and then just sit on discovery.

We are using Vlan 102 for our voice network, and vlan 104 for our data network.

Here is the 2950 config:

interface FastEthernet0/1
description ==Con to Cisco1721 Router==
switchport trunk native vlan 102
switchport trunk allowed vlan 102,104
switchport mode trunk
no ip address
duplex full
speed 100
!
interface FastEthernet0/2
description ==Con to Cisco Data Switch==
switchport access vlan 104
switchport trunk native vlan 104
switchport trunk allowed vlan 102,104
switchport mode trunk
no ip address
duplex full
speed 100
!
interface FastEthernet0/3
description ==Con to Mitel 3300==
switchport access vlan 102
switchport mode access
no ip address
duplex full
speed 100
spanning-tree portfast
spanning-tree bpduguard enable
!
interface FastEthernet0/4
description ==Connection to IP Phones==
switchport access vlan 102
switchport mode access
no ip address
speed 100
spanning-tree portfast
spanning-tree bpduguard enable

Ports 4-24 are the same config.

Here is the config of the cisco 3560:

interface FastEthernet0/1
description CONNECTION TO MPLS LINK
switchport trunk encapsulation dot1q
switchport trunk native vlan 102
switchport trunk allowed vlan 102,104
switchport mode trunk
speed 100
duplex full
!
interface FastEthernet0/2
description CONNECTION TO DATA SWITCH
switchport trunk encapsulation dot1q
switchport access vlan 104
switchport trunk native vlan 104
switchport trunk allowed vlan 102,104
switchport mode trunk
speed 100
duplex full
!
interface FastEthernet0/3
description CONNECTION TO MITEL 3300
switchport access vlan 102
switchport mode access
speed 100
duplex full
spanning-tree portfast
spanning-tree bpduguard enable
!
interface FastEthernet0/4
description CONNECTION TO IP PHONE
switchport access vlan 102
switchport mode access
speed 100
spanning-tree portfast
spanning-tree bpduguard enable

Ports 4-48 are the same.

So after many hours of trying to fix this problem, I take the new 3560 and put the old 2950 back in. Works straight away.

So can anyone shed any light on why we are having this problem?

 

[Mitelmatt]

Bit confused how your doing this as if the phone ports are access ports then you should be using CDP to get DHCP rather than double fetch mechanism. It allows the phones to boot quicker: To use CDP, make sure it's enabled on the switch;

Then the phone ports should have:

switchport mode access
switchport voice vlan 102 (depicts which is the voice VLAN
switchport access vlan 104 (used if pc's in back of phone)
spanning tree port fast

Then make sure the DHCP server in your 3300 is turned on and has addresses available

Are you using the 3560 as the router between the subnets? If so you will need to give each VLAN interface an address which is in effect the default gateway to that vlan.

It may have been that with the 2950 you were using IP helper addresses and your router to get DHCP

Hope this helps

 

[Ahdinko]

Hi Matt,

Will give those changes a go and see what happens.
PC's aren't in the back of the phones, PC's are plugged into the Data Switch which is connected to the 2950.

The routing is configured with a 2821 router as a router on a stick for the switches.

I can give the entire configs for both 2950 and 3560 if that helps.

 

[Mitelmatt]

Hi

Oh ok i see , you had one 2950 for voice and one for data.

Still try the config i gave and see what happens. If not yes send me both configs

Matt