L2 stack switch - to end-user devices

[SJ K]

Hi all,

I came across a design in my project today and realize that there are 3 x L2 stack switches which will be connecting to end-user computers.
According to the client, for end-user devices, he intend to just connect 1device/interface.

Q1) I am wondering, in this design, the only intention is to increase the number of interfaces/ports , am i right ? as there is only 1 physical cable for each connected device.

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In the same design, there is 2 x L3 switches which are meant for core network connecting to servers computers. They are stacked as well.
In this case, etherchannels are configured on the switches and servers which the 2 interfaces in 1 server are connecting to separate switches' interface in the stack.

Q2) Can I check, for this kind of switch stacking setup, are the etherchannels configure as active, active or it can be configure as active,passive ? or it is switches and servers dependable ?

Regards,
Noob

[Reza Sharifi · Accepted solution]

Hi,

Q1) I am wondering, in this design, the only intention is to increase the number of interfaces/ports , am i right ? as there is only 1 physical cable for each connected device.

That is correct.  The end devices (printers, PCs, laptops) usually have one physical cable and you can only connect them to one switch, but sometimes for mission critical environments engineers deploy multiple switches in case one of them goes out for any reason.

Q2) Can I check, for this kind of switch stacking setup, are the etherchannels configure as active, active or it can be configure as active,passive ? or it is switches and servers dependable ?

If you issue "sh etherca summay" on the stack, it will show you the port number that are part of that etherchannel.  As for active or passive, usually the switch is configured as active and servers as passive but you can also configure both sides as active.

HTH

[SJ K]

Hi Reza,
 

Thanks for the reply.

Q1) I am wondering, in this design, the only intention is to increase the number of interfaces/ports , am i right ? as there is only 1 physical cable for each connected device.

That is correct.  The end devices (printers, PCs, laptops) usually have one physical cable and you can only connect them to one switch, but sometimes for mission critical environments engineers deploy multiple switches in case one of them goes out for any reason.

What if in the event that 1 of the switch go down, as the switches are stacked, can i just plug out the cable @ interface let's say at switch1 fe0/1 and insert it into switch2 fe0/1 ? (provided it is not occupied)

Q2) Can I check, for this kind of switch stacking setup, are the etherchannels configure as active, active or it can be configure as active,passive ? or it is switches and servers dependable ?

If you issue "sh etherca summay" on the stack, it will show you the port number that are part of that etherchannel.  As for active or passive, usually the switch is configured as active and servers as passive but you can also configure both sides as active.
 

Do you mean on the server side, only 1 port will be receiving/sending information, but on the switch side, each interface at each of the 2 switches is able to receive/send ?
 

Regards,
Noob

[Reza Sharifi]

What if in the event that 1 of the switch go down, as the switches are stacked, can i just plug out the cable @ interface let's say at switch1 fe0/1 and insert it into switch2 fe0/1 ? (provided it is not occupied)

Yes, you can.  When switches are stacked, they are logically one switch, meaning you can use any port from any switch, as long as its not occupied.

Do you mean on the server side, only 1 port will be receiving/sending information, but on the switch side, each interface at each of the 2 switches is able to receive/send ?

No, active/passive is for protocol negotiation.  It has nothing to do with what port is sending/receiving traffic.  In general, when you create a portchannel with 2 physical links in it, both ports will be used if there are multiple hosts sitting behind the switch.

have a look at this doc for more info on how portchannel works:

http://www.cisco.com/c/en/us/support/docs/lan-switching/etherchannel/12023-4.html

HTH