Time Warner Cable - Legacy → [TWC] IP Address Lease Time Found!

Hey if anyone has been wondering what the lease time is for Time Warner Cable IPs, I have discovered that they give out a one hour lease time on their IP addresses. Not sure if this applies only to Earthlink High Speed Cable or anyone running through the Time Warner Cable network. If you need to find out your IP lease time and you're behind a router, follow these instructions bellow. (I did and it works)

1. Log into your Routers status page and release your IP address from your Router.

2. Disconnect the Ethernet Cable from your Modem and unplug the power from the Modem.

3. Plug the side of the Ethernet Cable that normally connects to the WAN port on the router and connect it to any PC, it doesn't matter as long as the PC has a NIC on it and has DHCP enabled for that NIC.

4. Connect the other side of the Ethernet Cable to the back of the modem and then connect the power again.

5. The modem should assign a temporary Automatic Private IP address while it contacts the local cable network your are on to give your modem a WAN IP.

6. Once this is done, go to Start, Run, and type CMD to open the Command Prompt. Then type ipconfig /all and look for the Lease time. It should give you the day and time that that IP expires.

Hope this is useful to those wondering how long to release their IP if they wish to attempt to change it. I haven't tried releasing it for an hour and seeing if it changes or not but I believe it should. Please note that the lease time goes by hours, minutes and seconds. So if you release at 10:30:53 AM, you would have to renew after 11:30:53 AM. Yes the seconds count, lol. Try it out and see if you have any luck. Post back and let me know how it goes for you! Enjoy!

Yours,
DJC2006 (David Thomas Maloney

NOTE: IF YOU'RE NOT BEHIND A ROUTER AND YOU HAVE A DIRECT CONNECTION TO THE MODEM, DO NOT FOLLOW THE ABOVE INSTRUCTIONS I'VE GIVEN. FOLLOW THESE BELLOW INSTEAD:

1. Go to Start, Run and type CMD to open the Command Prompt.

2. Type ipconfig /all and look for the Lease Time.

The assigned IP address will be given back to you even after it's expiration time as long as:

1. The equipment requesting the IP has the same MAC address.

2. The IP address previously assigned wasn't issued to another client during the time it was released. (This rarely happens unless there is a major outage, a shortage of assignable IP addresses, or the client released the IP for several days.)

So IF you want to change your IP, the easiest way is to change the MAC address of the device requesting it.

What MacLeech has just written is only part true. Although he does make some good points in the above post.

CREDIT FOR THE FOLLOWING POST COMES FROM THE ORIGINAL POST BY MACLEECH.

The assigned IP address will be given back to you even after it's expiration time as long as:

1. The equipment requesting the IP has the same MAC address.

Response: I've never had a problem with getting a different IP address on the same MAC address. So, I'm not sure how much this makes a difference but for me it doesn't seem to matter.

2. The IP address previously assigned wasn't issued to another client during the time it was released. (This rarely happens unless there is a major outage, a shortage of assignable IP addresses, or the client released the IP for several days.)

Response: This doesn't seem to always be a problem for me but he does have a good point here! If that IP address doesn't get taken by someone else, there is a 50/50 chance you might get the same IP address or a different IP address.

So IF you want to change your IP, the easiest way is to change the MAC address of the device requesting it.

Respone: Never done this before but have read plenty of posts that it seems to work, but I've read that it only seems to work one time so I've heard around the forums on www.dslreports.com So....do some research and experiment with this one.

Now as far as the process I posted in my post, I released my IP address at 5:16 PM Eastern Time and then renewed it at 6:16 and I got a new address. Before my IP address was 208.120.52.9 and now it's 208.120.52.XXX (Those X's represent that now I have three numbers in the last set instead of one.) So experiment and see what your results are as I made in the original post.

Its not 1 hour for every market. Southern California has a 24 hour lease for instance.... and if your have a Linksys Router with DD-WRT installed like myself, you don't have to do a whole lot to find out your lease time:

1) Go to the website of your Linksys router with DD-WRT.
2) Switch to the "Status" tab.
3) Click on "DHCP Renew"

And your lease time will be displayed, in my case it was:

Remaining Lease Time 0 days 23:59:54

In other words: 24 hours.

Many other routers have this (rather simple) feature by the way, I just happen to have a 3d-party firmware installed.

Yup...I've seen it in DD-WRT. I was going to check to see what my lease time was as I thought it used to be to be 48 hours. I couldn't find it! I knew it was in there...well, it turns out I remember seeing it when I setup another router for somebody that DD-WRT on it last month.

I still hadn't upgraded my router to SP2 from SP1. So, it's a new feature to SP2. I installed it today, and it seems like they've changed the lease time to an hour here in the nc.rr.com division, too.

I'm glad I did install it, though...I had to do a hard reset on the router, so the MAC that was cloned in it changed. It put me on a different subnet, and I'm getting spot-on 8 Mbps with exactly 1 MBps on actual downloads. Before, I was only getting about 7.8 Mbps down.

It's 24 hours in Charlotte, NC with rebind at 12.

Router#show dhcp lease
Temp IP addr: 69.132.x.x
for peer on Interface: Ethernet1
Temp sub net mask: 255.255.x.x
DHCP Lease server: 24.25.4.128, state: 3 Bound
DHCP transaction id: F98
Lease: 86400 secs, Renewal: 43200 secs, Rebind: 75600 secs
Temp default-gateway addr: 69.132.152.1
Next timer fires after: 00:47:05
Retry count: 0 Client-ID: cisco-0014.6986.aeb0-Et1
Client-ID hex dump: 636973636F2D303031342E363938362E
xxxxxxxxxxxx
Hostname: Router
Router#

just to clear it up, the first time the MAC is seen on the network it is issued a 1 hour lease. At the half way point it requests a renewal, and since the DHCP server already has record of it, it is issued a 24 hour lease from that point on.

This is true for the SATX division of RR.

Ryan

What Ryan has just posted....I think is correct....but I'm not sure.

Yours,
DJC2006 (David Thomas Maloney)

I'm sort of confused about whether what Ryan has posted is correct. I have released my IP address for 24 hours once and then renewed it and ended up with the same IP address. However, when I just release my modem for one hour and then renewed it only after a 1 hour release I got a different IP address. Was this just luck playing it's role? What is the IP lease time really, I thought what I posted was correct but now I'm not sure and I'm extremely confused. Anyone have any answers? All help is greatly appreciated!

Yours,
DJC2006 (David Thomas Maloney)

Per the DHCP RFC Section 4.4.5, the device assigned an IP will request a renewal at the 50% mark from the DHCP server.

»www.faqs.org/rfcs/rfc2131.html

Times T1 and T2 are configurable by the server through options. T1
defaults to (0.5 * duration_of_lease). T2 defaults to (0.875 *
duration_of_lease). Times T1 and T2 SHOULD be chosen with some
random "fuzz" around a fixed value, to avoid synchronization of
client reacquisition.

What do you mean by "releasing the modem"?

You are confusing yourself over something that is rather unimportant as well.

If you are swapping devices on the modem, from router to pc and such, the IP will change. The dhcp servers are different across all divisions/franchises and some take longer than 24 hours to "forget" the mac address of a router/pc and some dont. The 1 hour leases are put in place *usually* when there is maintenance on the network, sometimes there are even shorter leases. However, at least for san antonio, their lease times are 1 hour to start with for a newly attached device and then a 24 hour lease for each consecutive request until the device has been "forgotten".

By the way, what is the concern of whether your lease is longer or shorter than 24 hours? it does not affect connectivity if the process isnt hindered (i.e. not renewing 50% into current lease).

Ryan