10-14-2008 04:54 PM - edited 03-06-2019 01:55 AM
I am adding Cisco 7940 IP phones to our network. I don't have a router other than the ISP router to the internet. I have a C3750G-24TS switch that all my servers are connected and this is attached to a ASA 5510. I have replaced our workstation switch which is connected to the C3750G with a 3550-24 POE switch. All workstation are getting DHCP form a windows 2003 server 10.1.0.1. I have setup up a 2nd scope for the phones on the DHCP server.
I have connected the workstations to the Cisco phones and the phones into the 3550, the workstations are getting IP settings but the phones are not.
I have a Trunk port between the 2 switches and a switchport mode access for the port on the C3750G to the ASA 5510
Do I need to make any changes to the C3750 switch? Thanks for any Suggestions.
This is the config for the new 3550 switch
version 12.2
no service pad
service timestamps debug uptime
service timestamps log uptime
no service password-encryption/
!
no aaa new-model
mls qos
ip subnet-zero
no file verify auto
spanning-tree mode pvst
spanning-tree extend system-id
!
vlan internal allocation policy ascending
interface FastEthernet0/24
switchport mode access
switchport voice vlan 5
switchport priority extend trust
mls qos trust cos
spanning-tree portfast
!
interface GigabitEthernet0/1
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface GigabitEthernet0/2
switchport mode dynamic desirable
!
interface Vlan1
ip address 10.1.0.10 255.255.255.0
!
interface Vlan5
ip address 192.168.1.10 255.255.255.0
ip helper-address 10.1.0.1
!
ip classless
ip http server
ip http secure-server
10-15-2008 01:11 AM
Hi there,
The problem is that you have two VLANs, but you have no way of routing between them.
By this, I mean that your DHCP server is on the Data VLAN, but your phones are on a different VLAN.
I don't know the capabilities of the ASA 5510, whether it can do inter-VLAN routing or not. I know Cisco's routers can do it (as we've done it for our VoIP rollout across the UK) but I have no idea if an ASA 5510 can do it. Can anyone check that?
Either way, you need a router that can support 802.1Q trunking on its' LAN interface. You would need to set up two sub-interfaces - one for your data VLAN and one for your voice VLAN, and set the encapsulation on each subinterface, and set the IP Helper address for the voice VLAN to point to the DHCP servers' IP address. The phones should then be able to obtain IP addresses automatically.
Hope this helps!
Kind regards
Graeme
10-15-2008 01:35 AM
your C3750G-24TS should have the ip services images installed to do vlan routing between the vlans. Do you have a diagram showing how the phones/PC's are connected to which switch?
you should have a 802.1q trunk between the C3750G-24TS and 3550 switch to carry both voice/data vlans. make sure the voice/data vlan exist on both switches and your vlans SVI should be done on the C3750G-24TS for inter-vlan routing not on the 3550. include the ip helper-address on the SVI's.
The port both PC/Phone are connected to on the 3550 should be similar to the config below.
Switch#configure terminal
Switch(config)#interface fastethernet 2/5
Switch(config-if)#switchport mode access
Switch(config-if)#Switchport access vlan [data vlan]
Switch(config-if)#switchport voice vlan [voice vlan]
Configures the IP phone to transmit voice traffic in 802.1Q frames tagged with voice VLAN ID.
Francisco
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