VLAN Voice en Data

[breejedurpers]

We want to install an ip voice centrale.
We have two vlan's: Data, Voice.
Data have a ipadress:10.49.10.243 en Voice: 192.168.1.243.
The new telephone is a hub. The telephone must have a ipadres in the range of 192.168.1.x and the cable from the telephone goes to the pc in the range of 10.49.10.x. The DHCP from the voice is 192.168.1.1. Must we use an iphelper adress?

[nunocosta75]

hi, you need to configure the helper address with the ip of the dhcp server, so the switch can relay the dhcp packets to the dhcp server.
Regards.

[breejedurpers]

The ipadress from the DHCP server is:
192.168.1.1 and 10.49.10.19
Must i config some routes on the Procurve 2650?
like this:
192.168.1.0 255.255.255.0 192.168.1.1.
10.49.10.0 255.255.255.0 10.49.10.19.

[Pieter 't Hart]

If the switch has an ip-adress in both vlan's, no static route needs to be configured.
(implicit route exists because of interface in subnet).
you may check if "ip routing" command is active in switch configuration.

you configure the ip-helper adress on the vlan that does not contain the DHCP-server.

[breejedurpers]

We have the latest firmware.
On the procurve switch we can communicate with both vlans but not on the clients when we get an ipadress from the 192.168.1.x network. The cisco dhcp server have two ipadresses 10.49.10.19 and 192.168.1.1.
The DHCP give adress from 192.168.1.x
to 192.168.1.x. We place the cable from the switch in to a telephone en then to the telephone to the pc.

[Pieter 't Hart]

these lines are sufficient to make the
switch route between the two networks.
>>>
ip routing
vlan 20
ip address 192.168.1.1 255.255.255.0
exit
vlan 10
ip address 10.49.10.243 255.255.255.0
exit
<<<

the statement
>>> ip route 192.168.1.0 255.255.255.0 10.49.10.19
<<<
must be removed.
this does not result in connecting the two network. It may even work against you. as id directs the switch to send data for 192.168.1.0 out on vlan10 instead on vlan20!!!
routing is allready active just by using "ip routing".


the statement >>>ip default-gateway 192.168.1.1 <<
must also be removed as it points to the switches interface address.
If present at all, it should point to an external router.
But in conbination with using "ip routing" it's ignored anyway, and another command "ip route 0.0.0.0 0.0.0.0 " must be used.

What you probably miss is
>>>
vlan 20
name "Voice"
tagged 1-50
exit
vlan 10
name "Data"
untagged 1-50
exit
<<<
with this all ports use untagged packets in
the data-vlan, and port-7 ALSO sends tagged packets from the voice vlan to the phone.
the ip-phone receives all packets, listens to vlan-7 tagged packets (voice) and forwards untagged packets (data) to the PC.

your phone somehow must recognize vlan7 as it's own, either in its local config or centraly.

[breejedurpers]

This is the new config file.
I have changed the gateway adress to 10.49.10.20

[Pieter 't Hart]

the "ip default-gateway " will still be ignored.

so how does this config behave ?

>>>
vlan 20
name "Voice"
untagged 13-14
ip address 192.168.1.243 255.255.255.0
qos priority 7
ip helper-address 192.168.1.1
ip helper-address 10.49.10.19
tagged 7-12,15-50
exit
vlan 10
name "Data"
untagged 1-12,15-50
ip address 10.49.10.243 255.255.255.0
tagged 13-14
exit
<<<
You've got tagged and untagged reversed from my suggestion.
to my knowledge a port with both phone and pc must be untagged in data-vlan and tagged in voice-vlan.
but i allready asked how does this config behave?

the "ip helper-address 192.168.1.1" in vlan-20 can be removed. It will do nothing as this is in the same subnet as the interface itself (192.168.1.243)
But does this mean you have got 2 different dhcp-servers?
If each subnet has its own dhcp-server you don't need an ip-helper at all, and both ip helper lines can be removed.
an ip-helperaddresss is only neccessary from a subnet that does not have it's own dhcp-server

[breejedurpers]

We want to used the telephone as hub. In the telephone configuration we can make a option to go the data vlan. Is this possible when we used the voice as untagged en then data as tagged?

[Pieter 't Hart]

Yes I allready mentioned this :
"all ports use untagged packets in the data-vlan, and port- ALSO sends tagged packets from the voice vlan to the phone.
the ip-phone receives all packets, listens to vlan-7 tagged packets (voice) and forwards untagged packets (data) to the PC."

now with regard to "hub-ing".
A "hub" has no knowledge of vlans.
The phone when properly configured DOES.

- It passes untagged packets without interfering from the switch-side to the pc-side of the phone and vica versa
(thus works as a hub).

- It intercepts packets with the right vlan-tag that in the phone is configured as voice-vlan, and also responds with taggged packets.

So the switch knows which packets are sent from the phone (tagged) and which from the pc (untagged) and the switch can forward them to the rest of the network in the right vlan.