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[ncrjochen]

Good morning,

I have few stations on a 192.168.5.x  /24 subnet, and since last week my d'link DIR-890L router (192.168.5.1) started randomly dispatching 192.168.1.x addresses.

I do have another main router directly connected to internet, which is also the default gateway for my 192.168.1.x subnet, and which provides internet access to the 192.168.5.1 gateway.

Tried to track dhcp packets, and noticed three things :

*right after the dhcp ack happens between my host and the 192.168.5.1 router, another offer is sent to my host (tho in this case, my station had allready taken the offer of the correct subnet).

*when my station doesn't actually take the correct IP and goes for 192.168.1.x, wireshark only returns repetitive dhcp requests for a  192.168.1.x IP , and I can't track any discover  / offer nor ack packet.

*Dunno if it's normal, but wireshark returns packsts from both subnets.

It's my second week as a network administrator and this thing is driving me nuts help

[FurryNutz]

Link>Welcome!

• What Hardware version is your router? Look at sticker under the router case.
• Link>What Firmware version is currently loaded? Found on the routers web page under status.
• What region are you located?

So do you have the 890L connected to the main host router via it's WAN port?
Is the 890L using 192.168.5.1 as it's IP address?
What is the Mfr and model # of the main host router?
Can you use the 890L in LAN to LAN AP mode and let the main host router be your main DHCP server?

Have you tried connecting the 890L to the main host router and factory reset the 890L and walk thru the set up wizard and use it's configuration and re-configured IP address for the 890L. The 890L will detect conflicted IP address and change to a different IP address pool, i believe 10.something...

[ncrjochen]

Hi,

Thanks for your response.

Will need to check this by monday, I'll also perform a test with a different router to see if the main host (192.168.1.1) might be causing the issue.

In the meanwhile, I'd rather avoid a factory reset as a first approach as i need to know if I did something wrong in the setting, though there isn't much to configure in that one... But I agree that a conflict might indeed cause the issue.

[FurryNutz]

Is there a need for the 1st router? Most cases homes only need one router.

[ncrjochen]

Hi,

the second router is used as a dhcp server for the second subnet (.5), and here are the specs :
Hardware version : HW:A1
Firmware version : FW:1.20
Region : Morocco so Emea ?

I've given up to a reset though it didn't solve much, actually I'm now having issues on the main network as well (.1) in which devices are getting addresses following the (.5) subnet.

The structure is as follows : main router connected to a switch (the second port is used for other needs, firewall to a third network. And the two other ports are locked on VOIP / TV vlans).

The 192.168.5.1 router's wan port is connected to the same switch, as the .5 subnet starts from it.

I'm starting to suspect having two dhcp on the same unmanaged switch to be causing the issue, but the network always worked properly, the only change that has recently been made I guess is that they switched the managed (through not configured) switch and replaced it with an unmanaged one.

Thanks again

[FurryNutz]

Yes I presume this maybe an issue.

You can have two DHCP servers on the same line, however the 890L would need to be attached to the back of the 1st router and of course be using a different IP address pool string that differs from the 1st router. I have done this my self. I actually have a 2ndary router online with my first router and it's set for 192.168.78.1 while the 1st router is at 192.168.0.1.

Try putting the 890L right behind the 1st router connection wise and set a 192.168.89.1 IP address pool on the 890L, then set the pool size to 192.168.89.100 to .150. I presume your not putting a lot of devices on the 890.

If you don't need two DHCP servers on the line, then either run the 890L as your primary router or configure the 890L as a LAN to LAN AP behind the 1st router:
Turning a router into an AP.