Cisco 1861 Router Ports

[richardmaxw]

Hi,

On the lower-right side of the back of a Cisco 1861 router,  there are two ports which I'm unsure about. On page 8 of the following  PDF, they are referred to as an "FE port" and a "LAN Uplink" port: http://www.cisco.com/en/US/prod/collateral/routers/ps5853/ps8321/prod_presentation0900aecd806ccc34.pdf#page=8

There also appears to be a label underneath the "LAN Uplink" port that says, "Expansion." What purpose do these ports serve? Is the LAN uplink port for connecting to a modem? Does FE stand for fast ethernet?

Thanks,

Richard Maxwell

http://www.advantage-computer.biz

[grinch182 · Accepted solution]

Each Ethernet interface has two transmit pins + and - and two receive pins (the other pins may have wires running between them, but they are not used).  The transmit pins at one end of a cable have to be connected to the receive pins at the other end and vice versa. An uplink port does not crossover the transmit and receive pins and a regular port does.

If two hubs/switches are connected together with a straight-thru cable then one end must crossover (regular port) and one end must not (uplink port).  If a crossover cable is used to connect them, then the ports at both ends must be the same kind of port.  If a straight-thru cable is used to connect them, then the ports must be different.  A PC can be connected to an uplink port with a crossover cable and to a regular port with a straight-thru cable  Also, be aware that many hubs/switches share the uplink port with one of the regular ports, usually port 1.  Both ports will not work if they are both connected at the same time.  Finally, many hubs and switches have a switch associated with the uplink port that can switch the port between uplink and regular port configurations.

An "Uplink" port is provided for easy connection to other Switches or Hubs for network expansion

Hope it helps

Sincerely, GRinch

[richardmaxw]

Thank you very much for the explanation, GRinch! That makes perfect sense, and it is very informative. But I wonder what the FE port does, to the left of it? In the PDF, I can almost make out "WAN" underneath it.

Regards,

Richard

http://www.advantage-computer.biz

[Jigar Dave · Accepted solution]

Hi Richard,

The left port that you said will be connected to your ISP and right most port that you say uplink will connect with your LAN segment.

apart to that POE ports shown can be used to connect VoIP.

Cisco 1861 is well designed with considering small to medium enterprise network in mind where Voice, Network and Security all three things can be used together.

HTH

Jigar   

[grinch182 · Accepted solution]

I belive both of this ports works similar the only differense is the type of cable fo connection two devices. Why FE to the left of uplink port, IMHO it's just designers decision =) I think you can use it as your WAN port if IOS allow you to configure it this way.

Sincerely,

GRinch

[richardmaxw]

ok. Thanks again.