CCENT trunking question

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I was so delighted and totally surprised today to finally be informed about what was going on with the
"switchport trunk encapsulation dot1q" command.

I did not realize this was just for switch to switch communications. That is very valuable to know :-)

So the episode did bring two questions to my mind.

The first question is about the need for a crossover cable to be able to setup uplinks and trunks between switches.

I was dumped head first into an enterprise network without training, so I may be a little behind on this. But I do not think we are using crossover cables for any of our work. So I am wondering if maybe that is because the switches we use now are auto detecting and compensating for us?

The second question I have is, how would you set up a trunk between a switch and a router to pass all vlans? Do routers kill vlan tagging? Or do they pass it by default.

@LARRY-MILLER-2 said in CCENT trunking question:

I was so delighted and totally surprised today to finally be informed about what was going on with the
"switchport trunk encapsulation dot1q" command.

I did not realize this was just for switch to switch communications. That is very valuable to know :-)

So the episode did bring two questions to my mind.

The first question is about the need for a crossover cable to be able to setup uplinks and trunks between switches.

I was dumped head first into an enterprise network without training, so I may be a little behind on this. But I do not think we are using crossover cables for any of our work. So I am wondering if maybe that is because the switches we use now are auto detecting and compensating for us?

Most newer switches do not need the use of cross over cables between them. They support "auto-mdix" which will detect a regular straight through cable and know how to switch it at the interface.

The second question I have is, how would you set up a trunk between a switch and a router to pass all vlans? Do routers kill vlan tagging? Or do they pass it by default.

You must configure a switchport that is connecting to the router as a trunk.

On the router you must configure subinterfaces for each vlan if you're using a single port to route between vlans. This is called "Router on Stick." (not really used in production) Or if your router has multiple router ports on them, you can configure each port to be the default gateway for each vlan. Run cable from each vlan to the router port that you designated as the default gateway for that vlan.

If your router is actually a layer 3 switch you could just trunk all of the VLANs on the layer 3 switch just as you would a regular layer 2 switch