router questions

[GremlinHater]

Can a router act as a normal switch if you don't want to use it for connecting your network to the internet?
Can a router in general, handle any cable type? As in cross-over or straight or mixed?
Any recomendations for a decent router that has these capabilities if it's possible?

 

[Lord Evermore]

Any router with a switch integrated on the LAN side can be used as a switch, simply by not using the WAN port. You'd just plug your DSL/Cable modem, or your gateway machine, into one of the switch ports. (There's actually a couple of threads about this in Networking.) You'd need to configure it with a non-active IP address on the WAN, and disable the DHCP server in it.

Some routers may be able to be configured to act in "bridging" mode, where the WAN interface simply forwards all the packets to the LAN. However most cable/DSL consumer routers don't do this, since it completely bypasses the reason for buying a router in the first place. The main time you'd see it is for a vendor-supplied router, like from a DSL provider, since they just use one device to save time, and give you the option to either use their router's functions, or set it as a bridge so you can use your own.

Whether you use a crossover or straight-through cable isn't dependent on the type of router or switch, it's dependent on what devices you're connecting. Two ports like a NIC's port need a crossover cable. A NIC port to a hub/switch port needs a straight. Two hub ports need a crossover. An uplink to a NIC needs a crossover. An uplink to a hub port needs a straight. (A hub port is wired to be the "mirror" of a NIC, while an uplink port is wired the exact same as a NIC. In reality, a hub port is acting as a "crossover" point when connected to a NIC. Connecting an uplink port to a hub port is like connecting a NIC to it, because you must always connect ports as mirrors.)

 

[psteng19]

Some of the newer switches/routers come with auto-sensing "smart" ports (Auto MDI-MDIX) that will automatically detect the type of cable/device you plug in and therefore will perform the crossing-over for you.

Any router with a switch integrated on the LAN side can be used as a switch, simply by not using the WAN port. You'd just plug your DSL/Cable modem, or your gateway machine, into one of the switch ports. (There's actually a couple of threads about this in Networking.) You'd need to configure it with a non-active IP address on the WAN, and disable the DHCP server in it.

Any reason you suggest turning off the built-in DHCP server?
Why not just let the router assign IP's? They will be 192.168.X.X anyway, no?

 

[Lord Evermore]

Well, if someone is using the router just as a switch, then I'd assume they're connecting it to some other device they're using as a gateway which would be configured as a DHCP server, or directly connecting to a DSL/Cable modem with multiple DHCP assigned IPs from their ISP. Not disabling the one in the router would result in conflicts.