DPC3939B Private Wifi Question

We're moving our Comcast service to a new office. Old office has a Comcast modem w/no wifi, connected to a Linksys RV042 router, connected to a gigabit switch. There are three Cisco WAP4410 wifi access points which provide wireless access to the internal network. DHCP is provided to wired and wireless clients by Windows Server on our domain controller.

In the new office, a DPC3939B Business Wireless Gateway was installed, I figured great, now I can retire our unreliable Cisco wifi access points. I also replaced the RV042 with a ZyXEL ZWall 100 VPN Router. We have a static ip address.

I logged in to the DPC3939B and disabled DHCP, and configured the ZyXEL with the static address. A computer plugged into the ZyXEL works fine.

But I'm confused as to how wifi is going to work. If I disable DHCP on the lan, is that also going to disable DHCP on the private wifi and if so, will it just pass the DHCP requests on to the private wired lan? I don't see any way to configured DHCP for the private wifi.

If I have Comcast put the router in true bridged mode, will I lose the private Wifi and negate the benefit of having the DPC3939B in the first place?

Thanks to anyone who can help shed some light on this. I'm a 30 year programmer but not very experienced in TCP stuff, but we're too small to have an IT person on staff so I'm it.

Responses

CC_John

Retired Employee

•

1.9K Messages

10 years ago

Hi dcaton. Welcome to the Community. Disabling LAN DHCP on the Gateway does indeed disable DHCP on the private & public WiFi. With LAN DHCP disabled the gateway will only process request from devices that have statically assigned IP addresses. Also by placing the Gateway in all router functions and all WiFi functions are disabled (negated). In the device becomes a stand alone modem, just like a Motorola SB6141. Please let us know if further assistance is required

Thank You

0

dcaton

New Contributor

•

6 Messages

10 years ago

That's a bummer. The Gateway has a perfectly good dual-band Wifi radio that can't be used because there's no way to configure it. I understand that the router functions have to be disabled in true bridge mode, but that shouldn't have to disable the Wifi radio.

Why couldn't it just act as a stand-alone wifi access point accessible via one of the ethernet jacks? I know you can't answer that, just complaining out loud. But it seems to me it would only require a firmware update in order to allow that.

In any case, is the DPC3939B in true bridge mode a better device than the SB6141 or whatever we would get if we wanted a modem without wifi? If it's no better than any other modem and we're paying for wifi, then I'll call and have it replaced with a non-wifi modem.

0

dcaton

New Contributor

•

6 Messages

10 years ago

Can you please put our gateway into true bridge mode? I assume this will also disable the public xfinity hotspot, but so be it, that's not terribly important to us.

0

Comcast_Jon

Administrator

•

1.5K Messages

10 years ago

Hello dcaton,

Certainly, we can set the device to bridge mode as long as you do not have a static IP range,

Please send me the following information via private message so I may assist.

1. Your Full Name

2. Your Account Number

3. RF MAC address of the IP-Gateway

4. Your Contact phone number

Thank you

0