Why does the router stop showing the web interface and assigning ip addresses?

Question

Network administration

I have an old dlink router. Works for 3 years and distributes local ip to home machines.
Now I'm installing different Linux on virtualbox, and after a few days of these experiments, the router began to behave strangely:
It stops showing the web interface, stops assigning new ips, but the connection to already connected machines does not break and pings normally.
Why is he behaving this way and how can I fix it?
I did not find any "logs" of errors in the web interface of the router, and the connection via telnet does not occur.

Answer 1

If everything happened after fierce experiments, then perhaps his arp table overflowed or broke. Reset to factory and / or flash with fresh shit from long software.

Answer 2

Turn off all experimental linux and reboot the router. Perhaps, in the process of experiments, a DHCP server was launched, which had a fight with DHCP on the router - do you have it?

Answer 3

Memory runs out, OOM comes in, kills dhcp and httpd. The routing process cannot be killed - it is in the kernel.