hp procurve ....

[K.C. Chan]

All,
I've been ask to look into getting 2 gigabit switch for some of our servers in house. I noticed there are several types of switch out there. e.g layer 1 2 3 and 4th. Could some one enlightent what are the difference btw them and what disadvtage would it have on daily protocol usage, e.g nfs, types of broadcast, netbios, and so on ...

[Steven E. Protter]

Any of these switches will work just fine with regards to nfs, broadcast and netbios.

The various switch types may have additional useful figures such as the ability to handle voice over ip and such, but I do not believe there will be any impact on your Linux servers basic functions.

In your situation I'd assess the organization's needs and then get the switch with the fastest backbone possible based on the budget.

For more specific answers, provide the model numbers and manufacturers of the products you are considering.

SEP

[K.C. Chan]

Thanks for the reply; glad you didn't burned me on posting this here. I just found there's a separate forums for this under networking.

Mr. Moderator please move this post to an appropiate forum. Thank you.

[K.C. Chan]

I am thinking of getting 2 hp procurve 2824. One would be the backbone for trusted and the other would be a backbone for dmz. Does any one have a better model they would like to suggests. The only requirements I have from the powers that be, is 1Gbit. BTW, what is mini GBIC, I see references to it from the 2824 manual. Just for curiosity, does any one happen to know what layer is this switch? At first glance through the manual I do not see any reference as to what type of layer is the switch. Thanks.

[rick jones · Accepted solution]

At the risk of annoying my colleagues in the ProCurve side of the house, the term "switching" should _NEVER_ be applied to anything other than layer2.

Briefly:

Layer 1 of the ISO 7 layer model is the physical layer. There is no such thing as switching here, but there can be devices known as repeaters which simply amplify the electrical (photonic I suppose) signal and send it along.

Layer 2 of the ISO 7 layer model (the 9 layer model includes the Financial and Political layers...) is also known as the "data-link" layer - this is Ethernet, FDDI, etc. Switching at that level involves examining the destination station (MAC) address and perhaps some vlan tags and using that to determine the egress (exit) port on the switch to which the frame will be sent.

Layer 3 of the ISO model is the "network" layer - this is IPv4 or IPv6. What is really done here is called _routing_ - where the destination IP address and perhaps other fields of the IP header are examined to determine the IP interface out which the IP datagram will be fowareded.

Now at this point my knowledge gets a bit fuzzy, but...

Layer 4 of the ISO model is the Transport Layer - this is TCP, UDP and the like. When folks erroneoulsy talk of layer 4 switching, I believe this is actually either gateway functionality, or load balancing. The device peeks at the TCP or UDP header and makes decisions on where to send the segment (TCP)/datagram (UDP) next.

I myself have not tried any of the new 2800 series. I've been using some unmanaged 2724s, as well as some 4108s and been happy with them. I use them as basic switches. From the specs on www.hp.com though the 2800's look rather intriguing, particularly if you have a mix of copper and fibre, or want to start a transition from fibre to copper etc.