New setup of uc320w help needed

[Dturner4777]

Hi

Just installed uc320w for a customer and they are having some issues with PCs connecting to the internet, i dont think its a problem with internet itself but rather ther pcs loose connection to the adsl router which provides the DHCP. The customer has told me that if they unplug the phones then the pcs start working again.

The way i have it setup is the following.

ADSL 2 wire ROUTER port 1 - WAN UC320- lan port -sg300- port 1 of sg300 goes to a netgear switch as they only have 1 cable going to a group of desks which is a mix of spa303 and desktop pcs and the same config for port 2 of the sg300 switch goes to another netgear switch.

ADSL router port 2 - sg300 switch

I know im not meant to use the netgears but they only have 1 cable to each pod of desks, and it seems a bit strange to me why they would loose internet connection on there PCs.  If this setup is not going to work then i will just tell them to scrap the netgears and run some more cables.

Any help woud be great

Thanks

[markfurlong]

With the information provided it's hard to tell what's going on; is it possible that you are having IP address conflicts due to multiple DHCP servers?

What topology have you selected?  How many phones?  Are they all SPA303?  Do the Netgear switches handle QOS? and are they managed switches or unmanaged?

[Dturner4777]

Hi

The adsl router is setup as the dhcp for the PCs, and i have set the uc320 to route voice only, i have 3 spa303 and 1 spa525 which is connected via wifi. The netgears are unmanaged they are called netgear GS605.

Thanks

[Christopher Edgeworth]

Hi David,

A diagram might help in this scenario.  Here is a quick and dirty web tool for diagrams: 

http://www.diagram.ly/

Do you have two SG300 switches or are you reusing the same one with some special configuration of access ports and VLANS?  Did you configure VLAN 100 in the Netgear switch and configure trunk port between the Netgear and SG300?  We use VLAN 100 for the Voice VLAN and the native VLAN for the data subnet.

What IPs do you see on the phones and are they on the same subnet as the PCs?

Do you have two different subnets configured in the ADSL router one for WAN port and one for the SG300 switch?

Chris

[Dturner4777]

HI

see below diagram, the router cant do different subnets so the wan and lan are on the same subnet, and the netgear switches are unmanaged, i didnt configure a trunk port on the sg300 as i thought the sg300 smart ports would do everything automatically.

Thanks

[Christopher Edgeworth]

Hi David,

Having both interfaces of the router on the same subnet breaks a fundamental rule of routers.  Each routed interface should be on a different subnet.  In this case you have both the WAN and LAN on the same subnet--not good.

Have you considered a topology like this?

Are the Netgear switches managed switches or unmanaged?  If managed, you will need to create VLAN 100 on each switch and then make the uplinks and phone ports trunk ports with VLAN 100 tagged and VLAN 1 untagged (native).  If they are unmanaged, there is nothing more you need to do, VLAN tagged packets will pass right through.

Chris

[Dturner4777]

Hi Chris

So would the uc320w route the DATA as well and i would just bridge the wan on the uc320w to the dsl router.

Otherwise get a adsl router that can setup Vlans for different subnets on seperate ports.

Thanks

Dave

[Christopher Edgeworth]

Hi Dave,

The network design will depend upon your customer's network requirements.  If they require a large number of port forwards, a DMZ, or VPN capabilities, the diagram I've suggested may not be the best fit.  If their requirements are more basic, the topology above should work fine.  Yes, the UC320W will forward data traffic to/from the internet.

If you haven't already, would suggest spending some time with the Smart Design documents found here:

https://supportforums.cisco.com/docs/DOC-14783  in particular, the UC300 Implementation Guide, and Installing a UC300 in an existing network document.

Cheers,

Chris