Cogeco → [INTERNET] IP Addresses

Cogeco allows our area 3 computers directly connected to the modem
Question is - Are these Ip assigned to specific Mac Address?
I tried to install a router or/and new computer, cogeco will not assign an IP to it. ( PS I disconnected all computers first)
Tech support stated that the New Computer and New Router were faulty and to take them back.
How do I tell tech support to clear assigned IP = Mac Addresses
Great thanks, Been doing this off and on for 2 weeks

Have you reset the modem? I know on my system if I put something in the DMZ my modem will say 2 devices (the device and the router), if I do a pin reset on the modem and turn off the dmz it only identifies one device.

Yes. But I believe the IP of a disconnected item is freed up after the expiration time of the lease and may be picked up by another customer. If it's not picked up though, maybe you'll pick it up again? Not sure.I've been trying to pin down the exact methods for the many years I've been with Cogeco but there's two ways that have worked for me in the past decade:

1) Disconnect all my equipment from the Cogeco modem, hold the pin down as long as it takes to reset, leave equipment disconnected until the following morning and hold the pin down again to reset.

2) Call Cogeco and if you get someone that knows what you're talking about, he can do something on his end to resolve the issue.

Often when I try #2, I get someone on the other end that tries to give a lesson on basic networking or some such, but occasionally I get a guy that knows what I'm talking about and either puts me on hold and a short while later I'm good to go or he has to escalate the issue to somewhere else to free up the range.

There may be better methods but those have worked for me.

I was hoping that a cogeco rep was watching this to hope. Its helping out a poor neighbour and I have not reset the modem, but just about everything else.

mcelotto is correct. If you unplug all devices from the modem and do a pin reset, you can connect 3 entirely new devices to the modem before you'll have to do another pin reset.

Thanks, I will try it when I get home this weekend

How do you force the same devices to get an entirely different IP?

You will still get the same IP Address on your modem, it will just identify as having 1 device plugged into it (if your running it into a router, not a switch or hub)

After a factory reset of the modem, the device should get a new IP address since the MAC address memory has been erased on the modem. Now, if you connect a router to the modem, that is MAC address number 1 or 3. From that point forward, if you connect devices to the router, the router's DHCP lease will handle the other devices and will not reflect the MAC count on the modem.

I hope this helps!

Not true. A factory reset of a modem will not give either the modem or any devices behind that modem a new IP address.

Not true, if you hold in the reset button for 30 seconds and then release it, the device connected to the modem will get a new IP...just did it on mine!

I've never experienced that in all my years of using Cogeco. I admittedly haven't tried recently but I tend to trust nevertheless on the topic.

Yea, best to do that when it comes to DHCP or DNS

I don't doubt that your IP changed, but what made it change wasn't that you pin-reset your cable modem, what made it change was your operating system changed it's behaviour due to what happens when you pin-reset.

There's a few scenarios that can make your IP change, but the following is the most likely in your case.

• To start your OS has an IP address from the ISP's DHCP server. (ie: 1.1.1.1)

• When a cable modem is not online yet powered on it offers out private-space IPs for diagnostic purposes (192.168.100.X) with very short leases on it's ethernet port. While the modem was offline your client OS got one of these IPs (ie: 192.168.100.2) and threw away the info about the old IP address (1.1.1.1).

• When the CM comes back online your OS loses it's private space IP (192.168.100.2) due to expiry or DHCP NAK and your computer now has no IP address at all.

• Your OS sends out a brand new discover to the ISP's DHCP server.

• The ISP's DHCP server inspects your new discover finds an IP address for you, and continues the DHCP process.

That's the same for everyone, what changes your IP is what happened in your OS on that last point:

1) Your OS sends out a new DHCP discover and that discover contains the same info as the old DHCP lease you had (Ethernet MAC, client-id). The ISP's DHCP server issues you your old IP back to you (1.1.1.1)

2) Your OS understands that it's on a network it used to be on with a still-valid lease. Your OS sends out a DHCP request or a renew to verify the IPs are still valid using the previous identifying information (Ethernet MAC, client-id) and the DHCP server re-issues you your old lease (1.1.1.1).

3) Because your OS either forgot, threw out the old info, or is configured not to remember such things, your OS generates a brand new new client-id and sends out a brand new DHCP discover. The ISP's DHCP server sees your discover but it does not see the exact same identifying information (client-id) as the existing lease (1.1.1.1). This is a new client, or at least, a new instance of that client, and the DHCP server issues a different ip address (ie: 1.1.1.2).

What changed your IP isn't that you did the pin-reset, it's that your client operating system changed it's behaviour.

Here's an analogy: You're first in line to get into a Kiss concert and have all this awesome Kiss makeup and gear on. You've been waiting in line for 12 hours already and the big gulp you had is really putting pressure on your bladder. You pinky swear with the bouncer at the front to hold your place in line, and then head to the bathroom. While you were in the bathroom due to explosive peeing you end up having to wash up all the awesome Kiss makeup off of your face. When you get back from the bathroom the bouncer at the front of the line doesn't recognize you and makes you go to the back of the line and get a new spot in line (ie, a new IP). Leaving the line (pin-reset) didn't cause you to lose your spot in line--washing your face did.

Have you ever thought about teaching? :P

I love analogies but this may be my favourite.