Lots of Internet Problems; Please Help!

[legalassistant]

Hello, my name is Josh and I work for a law firm. The firm decided to purchase Mac computers, and the particular one I work on is an OS X Yosemite 10.10.3. Yesterday I came into the office, and my computer told me that another device was using my IP address. When I went to go renew my DHCP lease, in continued to give me the same IP address ending in xxx.xxx.xx.55. Upon investigation, this is in fact what the IP addressed assigned to my computer is supposed to be. My boss and I think that his iPad or his MacBook pro were the culprits. Once we turned off the modem and router and restarted them we finally got the router to assign my computer a new IP address. But then none of the devices in the building would connect to the internet. The hardware we are using is as follows: Cisco DPQ3925 Modem, NetGear Prosafe FVS318G router which was used as a firewall from what I'm told (bare with me I'm not a tech major I could be wording that incorrectly I just know we have a firewall and right now we can't use it), and we are currently using an Airport Extreme Baseport as our router currently so we can work. The IP address we are using now is completely different than what we were using before. When I plug the WAN cable into the Baseport directly from the modem our internet works. The WAN cable, from what I was told, was supposed to go to the router from the modem, and then an additional cord from the router to the Baseport. Does this make sense? Is there another reason this could possibly have happened? Are we doing something wrong? PLEASE HELP!

If anyone who is kind enough to answer this post needs more information, I can certainly provide it even though I tried to be as thorough as possible with our issues.

 

[Cory Cooper]

Hello and welcome.

-Does your firm have any IT personnel or a contracted IT company, or did someone in the office set up the network?

Networking issues can be difficult to diagnose remotely. You have three routers listed above (Cisco/NETGEAR/AirPort Extreme), which if not properly setup, can cause all kinds of networking/connectivity issues. They need to be configured properly to work with each other. If not, they all try to perform DHCP and NAT, which can prevent access to the Internet and network resources. They all have settings to enable different services such as DHCP/NAT/VPN/Firewall/etc.

Normally, connections for Internet service are as follows:

Coaxial cable from wall > cable modem > Ethernet cable out of modem > WAN port on router.

Connections vary when hardware VPN and firewall devices are added. You shouldn't need all three of those devices in your setup, unless you run the Cisco as only a modem, the NETGEAR as only a VPN/Firewall, and the AirPort Extreme as your wireless router.

I would definitely suggest that you contact a networking company to come it and properly setup the network, as it is far more involved than can easily be discussed/corrected via posts on this forum.

C