AC86U - DHCP not assigning IP.

[miazza]

Hi all.
I have a RT-AC86U running Merlin Firmware:386.12_4.

It happens that DHCP does not provide an IP to the NAS and other linux device (like Pi and Enigma2).
This happens only on devices connected via Ethernet and when it is some days that the theyare not powered and connected to the router.

A reboot from SSH does not solve the issue.
I also tried to reduce the lease time but without any success.

The only thing that works is to power cycle the router (OF and ON from the switch). After power cycle all the equipment are discovered.

Any Idea about how to investigate the issue ?

 

[bbunge]

Is it that the do not get addresses or the network map does not show them? What does the System Log/DHCP Leases show?

 

[miazza]

Is it that the do not get addresses or the network map does not show them? What does the System Log/DHCP Leases show?

They all have static IP reserved with the MAC Address and I cannot ping them.
If I look at the network map they are not shown.

.... I forgot to check the System log ... very stupid about me ... I will do it the next time.

If I have to guss, I would say that the issue started with RT-AC86U_386.12_0.

 

[DarrylJ88]

They all have static IP reserved with the MAC Address and I cannot ping them.
If I look at the network map they are not shown.

.... I forgot to check the System log ... very stupid about me ... I will do it the next time.

If I have to guss, I would say that the issue started with RT-AC86U_386.12_0.

Whats your subnet mask?

I've fallen foul in the distant past of setting one such as 255.255.255.240. So the DHCP could only assign 14-15 IPs. Just make sure that's 255.255.255.0

 

[bbunge]

They all have static IP reserved with the MAC Address and I cannot ping them.
If I look at the network map they are not shown.

.... I forgot to check the System log ... very stupid about me ... I will do it the next time.

If I have to guss, I would say that the issue started with RT-AC86U_386.12_0.

Static IP addresses are set at the client. Manually Assigned addresses are assigned by DHCP. There is a difference

 

[miazza]

Whats your subnet mask?

I've fallen foul in the distant past of setting one such as 255.255.255.240. So the DHCP could only assign 14-15 IPs. Just make sure that's 255.255.255.0

I checked. This is OK:

255.255.255.0

 

[miazza]

The command "service reboot" makes the trick.
It is not the same of a simple reboot.
Despite I have not understood why the DHCP get stuck and not assigning the IP to those devices that are not connected to the router during the last switch-on.