How does an UPLINK port on a Hub differ from other ports? 2

[Panther007]

I am trying to find out how does an uplink port on a hub differ from other ports on the hub? What makes this port different from other ports? When is it used? And why is it used?

Here's the complete scenario: I was plugging a hub between a cisco router and a cisco switch (to monitor internet traffic) and it required the switch to be plugged into the uplink port while the router was just plugged into the regular port...why???? What exactly does uplink port do??? How come the router didn't need to be plugged in the uplink port and the switch did??

Thanks in advance

 

[sobak]

The uplink port provides and internal crossover connection. If the hub didn't have an uplink port then you would have to connect the hub switch using a crossover cable. A cross over cable is where pins 1, 2, 3, and 6 are reversed to provide send and receive to the equipment. On equipment with a uplink port you can enable to automatic crossover with turning the uplink on. With the uplink off it functions just like a regular port on the hub.

Hope this clears it up a little....

david e
*end users are just like computers, some you can work with...others just need a simple reBOOTing to fix their problems.*

 

[RouterGod]

This CCO link may help eliminate some of your questions:

http://www.cisco.com/univercd/cc/td/doc/product/fhubs/fh112_24/guidelns.htm#xtocid30093

FYI...

Ethernet hubs can be uplinked to 10Mbps, 10/100 switches or broadband Internet devices. The back/front of each hub has an Uplink port for this purpose. The port itself is usually crossed over internally. As an example, when a "staight-through" cable is connected from standard port on a hub, it is intended that the transmit wire mates with the recieve wire. However when you connect a hub to a hub or a hub to switch you are mating transmit to transmit and so on. The internal crossover in the uplink port takes care of this for you. This is similar to using a cross-over cable. Cisco 1900's for example don't have a crossed-over uplink port, so you must use a cross-over cable when connecting a 1900 to another switch, say a 6500 or something.

If you are connecting the hub to another Ethernet hub or a 10/100 switch, remember that Ethernet rules only allow two hubs to be connected together, or uplinked, within a single network.

To uplink the hub, simply connect a regular straight-through Category 5 cable from the hub’s Uplink port to any regular network port on the hub or switch being uplinked.



Regards,

Don

 

[marks66]

If the switch is a Cisco you can "span" all traffic to a monitor port.

Cisco 5000 Series
set span 1 4/15 (sends ALL traffic on vlan 1 to module 4 port 15)

Cisco 29xx Series
int fast 0/1
port monitor vlan 1
(sends ALL traffic on vlan 1 to fastethernet 0/1)

Cheers

Mark