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And if it is possible are there any companies that are building these type of switches ? Are they/would they be much more expensive than a regular switch which has a more 'standard' processor and is programmed using software and then the program is loaded into the memory or flash, etc. ?

Would big companies like Cisco or Huawei be interested in building such switches? Would the prices cover the design costs ?

  • Did any answer help you? if so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you could provide and accept your own answer. – Ron Maupin Aug 7 '17 at 21:39
  • @yoyo_fun your question has been answered. As a side note programmable switches are in the market now so that you can program the hardware yourself to one run the exact features you need: p4.org – jwbensley Mar 24 '18 at 19:20
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As a general rule hardware is good when you have a relatively simple task that you need to do very quickly/frequently. Software is good when you have a more complex task that is not so speed-critical.

Unmanaged switches do pretty much everything in hardware. Their job is a simple one, add MAC addresses to a table, match MAC addresses against that table. It's simple but it needs to be fast and cheap, dedicated hardware is the order of the day. It wouldn't surprise me if there were some tiny processors inside doing initialisation stuff but if there are they aren't visible from outside.

Managed switches have a CPU to handle the management side of things. Building the management interface in hardware would be prohibitively expensive both from a development and production point of view. It would also make it impossible to fix bugs or add features after the hardware was produced.

A similar principle applies to high end routers, the actual high speed data forwarding is handled by dedicated hardware but the management side of things including talking to other routers is done in software.

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Modern layer-2 switches perform almost all switching in hardware. This facilitate wire-speed switching. Switching in software will slow down switching. Switches use software for added features.

Inconsistently, your last paragraph asks about routers. Routers do some things in hardware, but they use software because they need to support different interfaces and protocols. This, for example, allows a router to be upgraded to support both IPv4 and IPv6. Business-grade routers often have modular hardware, and you can get some very diverse hardware combinations. This really needs software support

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  • The router part was a mistake. I was curious about switches as I thought it would be much more easy to switch a packet using only hardware than do routing which is more complex. – yoyo_fun Nov 27 '16 at 0:35
  • As I wrote, modern switches do almost everything in hardware. It has been that way for a long time. – Ron Maupin Nov 27 '16 at 0:36
  • even consumer switches do this ? – yoyo_fun Nov 27 '16 at 1:10
  • Absolutely, although questions about consumer-grade equipment are explicitly off-topic here. The switching hardware is a commodity, and software is expensive. Your consumer-grade switches will only do layer-2 switching, and will not have extra features, so software is really unnecessary, except to do things like POST.. – Ron Maupin Nov 27 '16 at 1:14

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