What is chassis?

[viktar23]

Hello everyone!!!

I can't understand what is chassis in cisco devices. All I know chassis is a hardware part of the network device. But what does it contain? Are network interface, fan, power supply part of chassis? All cisco dievices have chassis?

Can someone explain or share useful link about this?

[marce1000]

 - I was brave enough to use the searching powers of the net , this is only an example result : https://networklessons.com/cisco/ccna-routing-switching-icnd2-200-105/chassis-aggregation#:~:text=Chassis%20aggregation%20is%20a%20Cisco,sometimes%20in%20the%20distribution%20layer.

 M.

[balaji.bandi]

Modular switches refers to network switches that are built in a medium to very large chassis

Chasis :

Flexibility
Better performance if line cards are interconnected internally by fabric
Multiple functions - List chasis can hold Switch ports - also FW Line cards, also Wifi Line cards.
Rapid increase in network ports
Power supplies

even though its quite old but still give you fare idea what is chasis

https://www.cisco.com/c/en/us/td/docs/solutions/Enterprise/Data_Center/dc_servchas/service-chassis_design.html

[Joseph W. Doherty]

Basically it's the framework/box that contains/holds all the device components.

Also see: https://en.wikipedia.org/wiki/Chassis

"All cisco dievices have chassis?"

Usually, but generally we only refer to the larger devices, with many modular slots, as a chassis device.  Also chassis device often had their "brains" as modules too.  "Non-chassis" devices often have their "brains" and sometimes power supplies more "permanently" attached the the chassis and/or neither of those are hardware upgradable.

A device with fixed "brains" and possibly power supplies, but which supplies slots for "network" cards/modules, is generally referred to as a "modular device".

"Are network interface, fan, power supply part of chassis?"

Again, usually.  Sometimes/often a large chassis device will provide a "backplane" into which everything else connects.

[Leo Laohoo]

A "chassis" means it is a "modular shell" and options are available to add-n-subtract various line cards, supervisor cards subject to the buyer's preference. 

Think of it as buying a car:  People buy car and accessorize.

[dltkdgns1296]

Chassis refers to the skeleton of the equipment.
I don't think you should think too hard about it.

good luck