By "gateway" I meant the IP address set in the various LAN devices for "default gateway" that (for the sake of the question) is set to 192.168.1.1.
Imagine that there is only one device (a PC) on the LAN and one DSL router/modem.
The router/modem (the actual "box") has an address of 192.168.1.1 and the only PC has set as gateway 192.168.1.1.
Now, let's say that there are instead several devices on the lan (all set with default gateway 192.168.1.1) and three DSL routers (that all have address 192.168.1.1 and that cannot be changed) of which only one is connected to the LAN at any given time by physically connecting/disconnecting from the main LAN switch their RJ45 cable (this is the current situation).
Instead of connecting/disconnecting manually the cables, I could put a "switch box" that would allow switching among the three routers cables, that would be something that anyone can be told to do over the phone in case of need.
I was asking if there was something ( a simple device) like that but that could be operated remotely or programmatically.
I presume that almost any router or managed switch (as it has been suggested, probably much better) can put a port in "up" or "down" state, but in the case of a router there would be some IP conflicts.
I could change the IP subnet and default gateway on all devices of LAN to (say) 192.168.0.x and have the "added" router be the default gateway at 192.168.0.1, routing all traffic to 192.168.1.1 (the fixed IP address of the DSL routers) but doing this, in case of failure of the "added" router I would have to change the default gateway on all the connected to LAN devices.
The "managed switch" sounds much better, though still if there was a simpler device it would be preferrable.
Comments
Maybe there has been a misunderstanding of sorts.
By "gateway" I meant the IP address set in the various LAN devices for "default gateway" that (for the sake of the question) is set to 192.168.1.1.
Imagine that there is only one device (a PC) on the LAN and one DSL router/modem.
The router/modem (the actual "box") has an address of 192.168.1.1 and the only PC has set as gateway 192.168.1.1.
Now, let's say that there are instead several devices on the lan (all set with default gateway 192.168.1.1) and three DSL routers (that all have address 192.168.1.1 and that cannot be changed) of which only one is connected to the LAN at any given time by physically connecting/disconnecting from the main LAN switch their RJ45 cable (this is the current situation).
Instead of connecting/disconnecting manually the cables, I could put a "switch box" that would allow switching among the three routers cables, that would be something that anyone can be told to do over the phone in case of need.
I was asking if there was something ( a simple device) like that but that could be operated remotely or programmatically.
I presume that almost any router or managed switch (as it has been suggested, probably much better) can put a port in "up" or "down" state, but in the case of a router there would be some IP conflicts.
I could change the IP subnet and default gateway on all devices of LAN to (say) 192.168.0.x and have the "added" router be the default gateway at 192.168.0.1, routing all traffic to 192.168.1.1 (the fixed IP address of the DSL routers) but doing this, in case of failure of the "added" router I would have to change the default gateway on all the connected to LAN devices.
The "managed switch" sounds much better, though still if there was a simpler device it would be preferrable.