DHCP Problem: IP Allocation problem

[vivex69]

I am using a RT-AX88U as the main router and a mix of 4 nodes (RT-AX86U, 2 units of XD4s and a RT-AC86U). I am using Merlin on my RT-AX86U, RT-AC86U and RT-AX88U.

As most of my devices at home does not support WiFi6 yet, so I disabled it on the Mesh router/nodes.

One thing I have noticed since the beginning is that these Asus routers are having problems allocating IP addresses on random devices. One device would not be able to connect properly, meaning WiFi is connected but without internet access and when you look on the allocated IP address it starts with 7.xxx.xxx.xxx.

What does this mean? What is causing this problem?

I would really appreciate some information about this problem and maybe a solution on how to fix this? Thank you

 

[ColinTaylor]

7.xxx.xxx.xxx is not a valid private IP address. What are the first three octets?

 

[vivex69]

Here are some of the IPs I have encountered

7.15.236.68
7.15.234.80
7.15.234.130

 

[Joseph Gan]

Nothing conclusive, but this is what I've found.

These look like previously-unused DoD IP addresses, now managed by Global Resource Systems, LLC.

It looks like this IP address range, which used to be owned by the DoD but are now dormant, are now managed by Global Resource Systems since April 2021, reportedly to identify malware using the IP address ranges:

https://www.washingtonpost.com/business/2021/04/26/questions-answers-pentagon-internet-protocol-addresses/

This IP address range looks like it is also used by at least a couple of Windows malwares:

Trojan.Win32.EQUATED.LZCXC - Threat Encyclopedia | 趨勢科技 (HK)

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

www.trendmicro.com

BackDoor.Maxplus.14318 — Dr.Web Malware description library

To ensure autorun and distribution: Modifies the following registry keys: [<HKLM>\SYSTEM\ControlSet001\Services\WinSock2\Parameters\Protocol_Catalog9\Catalog_Entries\000000000003] 'PackedCatalogItem' = '{6d,73,77,73,6f,63,6b,2e,64,6c,6c,00,00,00,00,00,00,00,00,00,00...

vms.drweb.com

 

[vivex69]

Thanks Joseph for the information.

I am wondering why the routers are providing such IP addresses. I have never encountered such problems from my older routers (other brands). This is the first time I am using Asus routers and this is the first time I have encountered such IPs.

Even if I reboot or power cycle my devices, the same IP address is allocated. But if I turn off the devices for almost a day, then there were chances that a valid IP address is allocated after turning back ON the devices.

 

[ColinTaylor]

My guess is that it is not the routers that are providing these addresses. Is it always the same devices that get these addresses or can it be any of your devices?

 

[fisherman10]

What is the IP address of your main router?
Show a screenshot of your router DHCP settings .