Question ISP router with ISP firmware as access point

[robashby]

I can’t flash my isp router with non non isp firmware and it doesn’t have an access point mode. (No other gigabit old routers)

Is it safe to use it as an access point by turning off dhcp and using a static ip? Or should I just be safe and buy a new one.

thanks

 

[kanewolf]

I can’t flash my isp router with non non isp firmware and it doesn’t have an access point mode. (No other gigabit old routers)

Is it safe to use it as an access point by turning off dhcp and using a static ip? Or should I just be safe and buy a new one.

thanks

What would make it "unsafe"? You aren't using the WAN port when using it as an AP. ISP firmware wouldn't try to use a LAN port to communicate back to the ISP.
I don't think there is a risk to your network.

 

[robashby]

I thought the same but everything I read says throw them away, nothing suggests repurposing them. Just wanted to make sure I am not missing something.

Thanks

 

[bill001g]

In general most consumer equipment only understand sending traffic going outside the lan subnet to the wan port. With nothing connected to the wan port it can talk to nothing outside. You might find some devices you can put in static routes but even that does not work all that well.

If you want to be very tricky just configure the lan IP to some completely different subnet 10.1.1.x or something. It would then have no ability to talk to any other device. When it is running in AP the user traffic going from the wifi radios to the ethernet is not using the IP on the AP anyway. It all passes more or less like a dumb switch.
If you would need access to the AP when it has a different IP you can put a secondary IP on your PC, but in general most times once a AP is setup you never touch it again.

 

[robashby]

Ok done this and it seems to be working really well. Only problem I have is that I can not connect to the main router when wired into the access point. Any thoughts?

thanks

 

[bill001g]

It is strange that you say it works but you can't access the router.

The devices connected to the AP can't get to the internet without going through the main router.

Verify that you have changed the IP on the AP so it is not the same IP as the main router.

 

[robashby]

Yes, AP ip is different from main router. Even stranger is that I can access the main router when I connect wirelessly through the AP. Just not when wired.

 

[bill001g]

I have no clue,this router must be "special?".

Years ago routers used to have a 5 port switch chip in them that runs the lan ports. It would have 4 ports connected to the lan ports and the fifth going to the router cpu chip. More modern routers now have this switch chip on the same silicon as the cpu but it functions the same.

In most routers you can't filter traffic going lan/lan. These switch chips are designed to be fast and use asic to switch traffic between the ports. Anything like say traffic filtering that would slow things down has been eliminated. The only way to filter traffic would be if the traffic would go up the connection to the CPU chip.
If you are using 2 lan port, one to the main router and the second to your PC the traffic should always stay on the switch fabric.

Something must not function in that way on your router.