what exactly do these commands do

assume that router bbb is connected to router aaa and router aaa gave router bbb a bad ip address from the dhcp so all the devices that are connected to router bbb have no internet

after that a laptop is directly connected to router aaa by using a network wire and the following commands are typed in sequence in elevated cmd:-
ipconfig /release
ipconfig /renew
ipconfig /flushdns
ipconfig /registerdns

what exactly do these commands do? do they only affect the laptop which is connected to router aaa or they will also fix the issue of router bbb?

Put simply it gets an IP from the router as the other was wrong. Router two should be connected via a LAN port to router one not a wan port so it doesn't get an IP from the router it's set on the router to be in same IP and subnet as router one

i'm sorry. i don't understand what you are saying. will the commands that i wrote fix the issue with router bbb?

cns00 said:

i'm sorry. i don't understand what you are saying. will the commands that i wrote fix the issue with router bbb?

No. Your ipconfig commands just tell the PC to forget everything it has got through DHCP from the bbb router and request a new IP address, DNS and default gateway from bbb's DHCP. BTW, if you are using IPv6 as well there are equivalent commands for that.

/release Release the IPv4 address for the specified adapter.
/release6 Release the IPv6 address for the specified adapter.
/renew Renew the IPv4 address for the specified adapter.
/renew6 Renew the IPv6 address for the specified adapter.

I am only using ipv4

If you are saying that those commands will not solve the issue then how do you think he fixed it? In the beginning there was no internet when I connected laptop to bbb. He came and he connected the laptop to aaa and he did something and that made router bbb get a good ip address and that fixed the internet on router bbb

The laptop may have been configure to use a fixed IP address and/or default gateway that worked only when connected to aaa. The technician may just have configured it to get those automatically through DHCP so it worked with both routers.

On router 2 goto the config page ensure the IP is in the same range as the other router but not the same is 192.168.1.66 turn off DHCP ensure network cable is in LAN port not WAN port it will then work as you get an IP from router one