Do you have internet access when this happen? What's the model.no of your router ?
is it on the latest firmware ?

Yes, internet access is fine when in this state. Shadowfax is actually my own laptop and the entry today is normal but there are now three similar entries for other devices (this is in a café BTW). It's a TD-W8960N V7 0x00000000 and I did check the firmware which I believe is up to date: 1.0.9 Build 160614 Rel.41323

My main concern is the DHCP table filling up with entries like this over time meaning new devices won't be able to get an IP address. I've got remote access to the router so will monitor over the next few days to see if the situation gets any worse.

BTW - I'm pretty sure I specified the model and firmware when I posted the message but it's not shown? Also, typing this response in IE is awful - have to type one character a second otherwise is misses characters. Doesn't work at all in Edge...

I initially thought that the 49710 days, 6 hours, 28 minutes, 15 seconds was a very big expiry date and in ~136 days i would finally expire :-) However, the value isn't going down - it's stuck at this figure. Which means if more of these bad entries get in there, the DHCP table will finally fill and no other clients will be able to connect.


I've also spotted this line:


CarolinesiPhone f0:79:60:7e:40:6d 192.168.1.105 0 seconds


This was there yesterday as well, i.e. it's stuck at 0 seconds and hasn't expired.


Does a reboot clear all the DHCP leases?


Thanks, Rob.

Another thought on that 0 seconds - several devices connected yesterday are now showing as expiring in 0 seconds. Maybe, because there are plenty of IP addresses left in the DHCP pool, the router will sort of "hang on" to the IP address for a recent device even when it's expired. So if it does connect again shortly, it gets the same DHCP address back? But if another device needed it (because DHCP pool had run out), then the 0 second address will be re-assigned. I know that DHCP likes to give the same client the same IP if it can.

A reboot will clear the DHCP release record, and reassign IP address to your devices. it will normally renew the IP address
I don't think that would be a issue, because the modem router can assign over 100 IP addresses
That's my opinion ;)

I'm rapidly coming to the conclusion that the TD-W8960N is a pretty buggy piece of kit and no use in a small cafe. Firstly, the DHCP table is filling up with entries with a lease time of "49710 days, 6 hours, 28 minutes, 15 seconds" and these *never* clear. The router I'm monitoring has been up for just 48 hours and there are now *54* entries like this. So in four days, the entire DHCP range will have been used up and who whether new customers will be able to get on.

If the 49710 entries do block new users then this is a blatent bug.


Also, I've been monitoring the Wi-Fi station list and that's not clearing down either overnight. At 8am this morning, there were 30 entries in there. If this unit is limited to 32 entries then this will explain why people are unable to connect. Fortunately disabling Wi-Fi and re-enabling remotely does clear this table down.


Not impressed! I know it's a cheap until but DHCP isn't that hard to get right...

*sigh* another bug found in DHCP. I wondered if one could clear the DHCP leases by disabling DHCP and then re-enabling it. Sounds sensible doesn't it? Nope, not on this router. Instead you end up with the " 49710 days" entry for every entry that was in the table:

suggest you contact the support team at [EMAIL="support@tp-link.com"]support@tp-link.com[/EMAIL], they will response.

OL - I'm sometimes far too geeky/my programming routes show.

I wondered if that figure was some magic number and it is... I guessed that the DHCP lease time is stored internally in seconds.


So the formula would be: Days*24*60*60 + Hours*60*60 + Minutes*60 + Seconds


If you plug in 49710 days, 6 hours, 28 minutes and 15 seconds you get 4,294,967,295 which is FFFF FFF in hex. That's too much of a coincidence - the DHCP system is putting -1 (FFFF FFFF) in a 32-bit field for some reason and the DHCP table display code is blindly converting it to days, hours, mins and seconds.

I find a new firmware for TD-W8960N V7 here. http://www.tp-link.com/en/download/TD-W8960N_V7.html#Firmware
Give it a try?