Help with DHCP issue

[ImaStinker]

Hello, and HELP!

Ever since I got my ASUS RT-AC66U, my wife has been suffering trying to use her Lenovo IdeaPad U530 laptop. Specifically trying to connect to the internet. Something is going wrong with the DHCP handshaking. It doesn't matter if a make a DHCP reservation for her laptop or not. Nor does it matter if the connection is wired or wifi. Other devices don't seem to have this problem. I recently updated firmware to RT-AC66U_380.58_0 hoping it would help, but no joy. The Lenovo doesn't have this problem with my WRT54GL router.

I'm hoping someone here could help with a setting to make things a bit more robust?
I remember that with the WRT54GL 1st gen iPhone had the same type of issue and there was a setting change that helped.

• Change beacon Interval 75
• Change RTS Threshold to 2304
• Change Fragmentation Threshold to 2304.

However, the ASUS/Merlin firmware doesn't have a "Fragmentation Threshold" setting. At least I can't find it. Any ideas?

Relevant log section follows.

Thanks.

...
Apr 22 08:41:51 dnsmasq-dhcp[247]: DHCPDISCOVER(br0) c4:54:44:00:yy:zz
Apr 22 08:41:51 dnsmasq-dhcp[247]: DHCPOFFER(br0) 10.xx.xx.233 c4:54:44:00:yy:zz
Apr 22 08:41:51 dnsmasq-dhcp[247]: DHCPREQUEST(br0) 10.xx.xx.233 c4:54:44:00:yy:zz
Apr 22 08:41:51 dnsmasq-dhcp[247]: DHCPACK(br0) 10.xx.xx.233 c4:54:44:00:yy:zz Tweety
Apr 22 08:41:51 dnsmasq-dhcp[247]: DHCPDISCOVER(br0) c4:54:44:00:yy:zz
Apr 22 08:41:51 dnsmasq-dhcp[247]: DHCPOFFER(br0) 10.xx.xx.233 c4:54:44:00:yy:zz
Apr 22 08:41:51 dnsmasq-dhcp[247]: DHCPREQUEST(br0) 10.xx.xx.233 c4:54:44:00:yy:zz
Apr 22 08:41:51 dnsmasq-dhcp[247]: DHCPACK(br0) 10.xx.xx.233 c4:54:44:00:yy:zz Tweety
Apr 22 08:41:51 dnsmasq-dhcp[247]: DHCPDISCOVER(br0) c4:54:44:00:yy:zz
Apr 22 08:41:51 dnsmasq-dhcp[247]: DHCPOFFER(br0) 10.xx.xx.233 c4:54:44:00:yy:zz
Apr 22 08:41:51 dnsmasq-dhcp[247]: DHCPREQUEST(br0) 10.xx.xx.233 c4:54:44:00:yy:zz
Apr 22 08:41:51 dnsmasq-dhcp[247]: DHCPACK(br0) 10.xx.xx.233 c4:54:44:00:yy:zz Tweety
Apr 22 08:41:51 dnsmasq-dhcp[247]: DHCPDISCOVER(br0) c4:54:44:00:yy:zz
Apr 22 08:41:51 dnsmasq-dhcp[247]: DHCPOFFER(br0) 10.xx.xx.233 c4:54:44:00:yy:zz
Apr 22 08:41:51 dnsmasq-dhcp[247]: DHCPREQUEST(br0) 10.xx.xx.233 c4:54:44:00:yy:zz
Apr 22 08:41:51 dnsmasq-dhcp[247]: DHCPACK(br0) 10.xx.xx.233 c4:54:44:00:yy:zz Tweety
Apr 22 08:41:51 dnsmasq-dhcp[247]: DHCPDISCOVER(br0) c4:54:44:00:yy:zz
Apr 22 08:41:51 dnsmasq-dhcp[247]: DHCPOFFER(br0) 10.xx.xx.233 c4:54:44:00:yy:zz
Apr 22 08:41:51 dnsmasq-dhcp[247]: DHCPREQUEST(br0) 10.xx.xx.233 c4:54:44:00:yy:zz
Apr 22 08:41:51 dnsmasq-dhcp[247]: DHCPACK(br0) 10.xx.xx.233 c4:54:44:00:yy:zz Tweety
...

 

[eddiez]

Did you completely remove all connection details to the router/SSID on the laptop? This seems to be caused by the laptop. You could also try to refresh the whole TCP/IP stack on the laptop.

Wireless is an Intel chipset and the LAN RJ45 is probably a RealTek chipset, so the only relationship is the Windows config

 

[ColinTaylor]

I'd agree with eddiez, it seems more likely to be a Windows issue (assuming you're using Windows).

I've noticed that Windows 8/10 seem particularly bad at accepting a change of IP address, I don't know why.

I find that often I have to disable the network adapter and then re-enable it to pick up the change. Rebooting the PC doesn't seem to work.

 

[ImaStinker]

Yep, done all that. I've had various other devices with the same problem intermittently. Some Android, some Apple. Mostly windows. This Lenovo U530 is rather obnoxious about it. I'm just wondering if there is something I can do to ease the dhcp process, or relax the timing some.
It seems all these newer devices are too quick to drop into APIPA mode. That's really bothersome when you're not running your network on 192.169.1.x.

 

[eddiez]

Yep, done all that. I've had various other devices with the same problem intermittently. Some Android, some Apple. Mostly windows. This Lenovo U530 is rather obnoxious about it. I'm just wondering if there is something I can do to ease the dhcp process, or relax the timing some.
It seems all these newer devices are too quick to drop into APIPA mode. That's really bothersome when you're not running your network on 192.169.1.x.

Any tweak or change done to the OS could cause issues. So you might want to make sure you set all of those settings to true default. Since both hardware component (from different vendors and not integrated) suffer from the same issue an OS issue seems the root cause. So since only Apple specific issues are known for these routers (or better: widely used SOC), it would be unlikely that a problem would appear only now.

 

[mstombs]

It seems all these newer devices are too quick to drop into APIPA mode. That's really bothersome when you're not running your network on 192.169.1.x.

APIPA is 169.254.x.x ...

I wonder if you can interrogate the problem from a windows command line using the "netsh" command, if it still works with recent versions...

http://www.practicallynetworked.com/networking/manage_windows_network_settings_with_netsh.htm

 

[eddiez]

Did you check your firewall or AV blocking or limiting dhcp ...? Some AV cause an issue when activating SmartDHCP rules.

 

[ImaStinker]

This is just too much.
I have the DHCP reservation for the laptop: Router DHCP Reservations.PNG
I made a corresponding static IP assignment on the laptop.
The laptop is now connected to the router, but can't get internet access: Lenovo Network Connections.JPG
I should mention this is the chief complaint my wife has--connected, but not internet.
--part 1 of 3--

 

[ImaStinker]

--part 2 of 3--
So I check the router: Router Wireless Log.PNG
It sees the MAC address, but there is no IP assigned--just weird.
Now, all I do is play around on the router. I'm already on the System Log page and viewing the "Wireless Log" tab. I select the "Connections" tab and hit refresh. It seems strange to me to see in the results that laptop IP address has connections to the internet that are listed as ESABLISHED.
So I click back on the "Wireless Log" tab and what do I find: Router Wireless Log After.PNG
Now there's an IP address...

--continued--

 

[ImaStinker]

-- part 3 of 3 --

I check back on the laptop and what do I find: Lenovo Network Connections After.JPG
Everything is now Magically Delicious. I really don't know how long this will last.
I've double checked the General Log, but nothing is showing up there.

Apr 24 11:32:21 rc_service: httpd 726:notify_rc restart_wlcscan
Apr 24 11:36:45 smbd[8085]: [2016/04/24 11:36:45.234169, 0] smbd/sesssetup.c:1355(reply_sesssetup_and_X)
Apr 24 11:36:45 smbd[8085]: reply_sesssetup_and_X: Rejecting attempt at SPNEGO session setup when it was not negotiated.
Apr 24 11:36:45 smbd[8086]: [2016/04/24 11:36:45.279868, 0] smbd/sesssetup.c:1355(reply_sesssetup_and_X)
Apr 24 11:36:45 smbd[8086]: reply_sesssetup_and_X: Rejecting attempt at SPNEGO session setup when it was not negotiated.
Apr 24 11:55:26 dnsmasq-dhcp[5681]: DHCPDISCOVER(br0) 00:1f:5b:58:89:09
Apr 24 11:55:26 dnsmasq-dhcp[5681]: DHCPOFFER(br0) 10.77.77.212 00:1f:5b:58:89:09
Apr 24 11:55:27 dnsmasq-dhcp[5681]: DHCPREQUEST(br0) 10.77.77.10 00:1f:5b:58:89:09
Apr 24 11:55:27 dnsmasq-dhcp[5681]: DHCPNAK(br0) 10.77.77.10 00:1f:5b:58:89:09 address not available
Apr 24 12:04:43 ntp: start NTP update
Apr 24 12:31:44 rc_service: httpd 726:notify_rc restart_wlcscan
Apr 24 12:47:30 smbd[8332]: [2016/04/24 12:47:30.559503, 0] smbd/sesssetup.c:1355(reply_sesssetup_and_X)
Apr 24 12:47:30 smbd[8332]: reply_sesssetup_and_X: Rejecting attempt at SPNEGO session setup when it was not negotiated.
Apr 24 12:47:30 smbd[8333]: [2016/04/24 12:47:30.582814, 0] smbd/sesssetup.c:1355(reply_sesssetup_and_X)
Apr 24 12:47:30 smbd[8333]: reply_sesssetup_and_X: Rejecting attempt at SPNEGO session setup when it was not negotiated.
Apr 24 13:29:37 kernel: nf_ct_ras: decoding error: out of range​

Whew, that was a lot. Any ideas?

 

[ImaStinker]

Next time the laptop has trouble, i.e. later today, I will give the netsh command a go and see what I can find... But really, I poke the ASUS router, and my wife's laptop starts to work. Done this multiple times over the past year. I thought it was outdated FW, that;s why I upgraded to 380.58_0. Shows what I know.