OpenWrt Forum Archive

Topic: DHCP Problem - Linksys WRT1900ACS and OpenWrt Chaos Calmer 15.05.1.

The content of this topic has been archived on 30 Mar 2018. There are no obvious gaps in this topic, but there may still be some posts missing at the end.

Hi,

I have 2 Linksys WRT1900ACS routers (installed on opposite sides of office space) and OpenWrt Chaos Calmer 15.05.1.
WAN connected to corporate LAN on fixed IP.
2 WiFi networks on each router (in 2 zones), LAN for employees and GuestLAN for everyone else.
Very standard configuration for DHCP
Router #1 - WiFi A 2.4 GHz, WiFi A 5.0 GHz (192.168.11.x), GuestLan A 2.4 GHz (192.168.12.x)
Router #2 - WiFi B 2.4 GHz, WiFi B 5.0 GHz (192.168.13.x), GuestLan B 2.4 GHz (192.168.14.x)
GuestLAN have restrictions, like ping, blocked SSH, SMB, etc to LAN & WAN.

Now the problem. DHCP server seem to hangs time to time. Overview shows few active DHCP leases (far below limits), activity indicator blinking, yet no actual traffic go through WiFi. Attempt to connect new DHCP client results in bogus (non-existent) IP address.
DHCP lease time is 12 hours.

What could be the problem ?
This particular router is very popular, so possibly I'm not alone with this issue

Configure DNSMASQ to log all DHCP queries, and see if there is any relevant message.

Seems like problem can be solved with this cron script.
Today installed, let's see if it solves the problem.

BTW, don't run
echo "* * * * * /root/dog.sh" | crontab -
as is, it will overwrite current crontab "root" file.

https://gist.github.com/murix/fbd89f47f … 40e7cf2f4d

# fix wpad / wpad-mini / hostapd stop working bug
# fix kernel bug
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(Last edited by LinuksGuru on 31 Jul 2017, 13:53)

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