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RB260GSP + 2.7 How to make switch only give ip from WLAN dchp to one device on the inside?

Posted: Wed Feb 28, 2018 8:00 am
by SwitchNewb
Hi,

I'm a newbie at both networking and mikrotik, i am having some issues forcing my router on the inside getting dchp from my internet provider, here's my setup.

Incoming Fiber (ISP only gives 1 ip address per household) <-> Mikrotik rb260gsp SFP fiber port (WAN)
Mikrotik Port #1 <-> Ubiquiti Edge Router (Edgerouter looks for dhcp on eth1 which is connected to mikrotik port #1)

Everyting works fine if i only have these 2 devices connected... But if i connect the rest of my devices to port #2, 3, 4, 5 and reboot the Mikrotik switch, it's random which device gets the ip from the dhcp from the isp, and since they only give 1 ip the other devices get locked out.

My question is basically, how to i force the mikrotik switch to only give ip to the device that is connected to port #1 and the other ports are internal switching only?

Re: RB260GSP + 2.7 How to make switch only give ip from WLAN dchp to one device on the inside?

Posted: Wed Feb 28, 2018 2:09 pm
by SwitchNewb
I think i figured it out.

Tell me if my logic is correct

Image
Internet comes in via SFP, the router is connected in port 1 ... port 1 and sfp are the only ones that communicates with each other, port 2,3,4,5 are switched together, will this result in what i want? Will only my edgerouter which is connected directly to port 1 be the only device who receives DCHP from internet now, as port 2,3,4,5 are isolated from directly communicating with port 1 and sfp?

My router is my DHCP and i need the router to be the host for internet.

If my logic is wrong let me know!

Re: RB260GSP + 2.7 How to make switch only give ip from WLAN dchp to one device on the inside?

Posted: Sun Mar 04, 2018 4:28 pm
by k6ccc
Your switch is in the wrong place. Since your ISP provides you only one address, there should only be one device that can directly see the ISP connection. That should be your router WAN port. Everything else should be downstream of the router. If you used your arrangement in your second post, the devices connected to ports 2 - 5 could communicate with each other, but nothing else.

Re: RB260GSP + 2.7 How to make switch only give ip from WLAN dchp to one device on the inside?

Posted: Tue Mar 06, 2018 10:48 pm
by SwitchNewb
Your switch is in the wrong place. Since your ISP provides you only one address, there should only be one device that can directly see the ISP connection. That should be your router WAN port. Everything else should be downstream of the router. If you used your arrangement in your second post, the devices connected to ports 2 - 5 could communicate with each other, but nothing else.
Sorry i forgot to mention, from a switch port in my router another cable goes back to the mikrotik so the 3 ports can communicate with the rest of the stuff in the network, it works fine now, thanks!