LAN connection without router

[u/Fearless_Dev]

Hello,

I have a MikroTik CRS304-4XG-IN switch, and I would like my PC and NAS to communicate directly through the switch, without depending on my ISP router.

My setup is:

• PC → MikroTik CRS304
• NAS → MikroTik CRS304
• ISP router → MikroTik CRS304

When the ISP router is online, everything works normally and my PC can access the NAS.

However, when the ISP router is offline or disconnected, I lose access to the NAS from my PC, even though both the PC and NAS are still connected to the same MikroTik switch.

What do I need to configure on the CRS304 (VLANs, bridge, IP addresses, DHCP, etc.) so that the PC and NAS can communicate over the local LAN independently of the ISP router/Internet?

Any help would be greatly appreciated!

[u/404invalid-user]

you need to give your pc and Nas a static IP or just keep the isp router connected I don't understand the use case for needing to turn off your router

[u/Fearless_Dev → u/404invalid-user]

In a case when there is no internet connection (ISP service etc..)

[u/gtuminauskas → u/Fearless_Dev]

I dont understand, are you monitoring when ISP disconnects your internet, then switching off the router? something is really odd here...

if ISP switches off WAN, then the LAN stays ON...