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Just Checking

Link Aggregation/Trunking - Managed Switch Choice

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Just Checking

I am working on my home network and using it as a learning tool.  I am not a network engineer and have no formal training in this field, just what I learn by reading and asking a lot of questions on forums like this one.

 

I am building a new server which will have multipe gigabit ethernet ports (up to 5 ports).  Currently I route all network traffic through a gigabit unmanaged Zytel 24-port switch which works fine except that my network bandwidth is limited to 1 gigabit in each direction.  A second section of my network is not directly accessible to my primary switch because I didn't leave enough length of the Cat 6 cables when I was putting in the runs so I have a second unmanaged Zytel gigabit switch for that.   I currently run ethernet between the two switches  but that is limited to 1 gigabit also. 

 

From reading in forums and white papers, it is clear that I have to purchase managed switches to be able to do Link Aggregation and increase my  bandwidth between my server and the two switches.   I talked to a couple of network guys have been looking around at used switches.  I am soliciting opinions on which switches would be the best for me to purchase given that I am a relative neophyte when it comes to network configuration.   I have not used Hypertext in decades.

 

Here are some that I have been considering:

1. Cisco Catalyst 2970g - 24 port managed gigabit switch

2. Netgear Prosafe GS748T - 48 port managed gigabit switch

3. Dell Powerconnect 5524 (or something similar) - 24 port managed gigabit switch

 

The Cisco and Netgear models do support LInk Aggregation and are gigabit switches.  Cisco supports aggregation of up to 8 ports while Netgear supports aggregation of up to 5 ports.  I am having trouble determining which Dell models support Link Aggregation.  When they do, Dell models support up to 5 ports being aggregated.  

 

I am looking for input as to which switches are easier to use and have better support, features, etc.  Yes, I realize that these switches are considered EOL by the manufacturers.   This is my home/small business network and I am not going to be spending thousands for a new switch.   I need a minimum of 24 ports if I do Link Aggregation and 48 ports would be nice for my main switch (not absolutely necessary but if I can get it inexpensive enough, why not go for it).  I would also like opinions on which are quieter, use less power, good choice for a home environment (not a temp/humidity controlled server room).  

 

Thanks in advance.   BTW -  I just won a bid on a Cisco 2970g but I need at least one more switch to put into my network.   If anyone has information on whether Netgear, Dell, or other switch mfg's play together with this Cisco switch, I would appreciate that info too.

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cskenney

My first thought is do you actually have enough network traffic to warrant going to all the trouble of link aggregation?  How much traffic do you currently have on your network and is it slowed down by the hardware in the devices that are sending / receiving the traffic?

 

Just curious....don't let me deter you from learning new stuff.

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Just Checking

Actually, I do a lot of processing of large files (5-50GB).  I batch process these files on workstations then send them back and forth across the network.   For certain backups, I send several TB of information between servers and workstations.  It is not constant but, I actually do use bandwith in the 3+Gbps range - if my network would support it.   I am currently limited to the 1Gbps that my current network provides.  

 

I could get by with 3Gbp for a network bandwidth.   Because I have an engineering background and, because it is really no more expensive to do it, I have a goal of having a network bandwidth capacity of 5Gbps.   I thought about shooting for 10Gbps bandwidth but that would raise the pricetag up by an order of magnitude, or more.   I could put multipe 4-port gigabit ethernet cards in my server but I have not found inexpensive switches that will Link Aggregate 10+ ports.  From what I can tell, this is getting into some serious enterprise level networking that would take a lot more studying before I want to take on right now.  

 

For less than the cost of a few 8GB ECC DIMM's I can get the hardware to make a 5Gbps network.

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oj88

I use a D-Link DGS-1210-20/E managed switch in the main data closet on the 2nd flr. I have a couple of Cat6 UTP cables going to the Gnd flr. where the other family members are. Currently, only one of the cables are live (gigabit) and I eventually intend to purchase another managed switch for the ground flr. so I can; a) Combine their bandwidth and B) Have some level of high availability, even for just when one of the cables were chewed on by a rodent. :)

Edited by oj88

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ikon

I would urge you to stick with a single manufacturer when doing aggregation.

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oj88

^ Agree. Goes without saying.

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Just Checking

I would urge you to stick with a single manufacturer when doing aggregation.

What type of problems should I expect to encounter?   The IEEE standard 802.3 for LACP was implemented back in 2008.  That is more than 5 years ago.  According to the Wiki, mfg's were discussing standards as far back as the 1990's and the IEEE standard 802.1 was agreed upon in 2000. 

 

http://en.wikipedia.org/wiki/Link_aggregation

 

I purchased a Cisco 2970g 24-port managed switch on the recommendation of a network guy I talked to at my wifes work.  He showed me the setup they use at tradeshows and explained how they were excellent workhorses which are pretty bulletproof.  The 2970g's are layer 2 switches and use Hypertext for programming/management (though they supposedly are capable of being web managed, all the network guys I talked to said "forget about that").  Cisco 2970g's have to be used with a router or layer 3 switch... I am not sure what the difference between a router and layer 3 switch is.

 

I am thinking of getting a Netgear Prosafe GS748T 48-port "soft layer 3" managed switch to use as my primary switch and router for my network.  Currently, I am using the C1000A modem/router that is provided by Centurylink DSL.  I would like to turn off the router function (If I can figure out how to do that - nothing in any of the documentation gives a procedure on how to turn off the router functionality) as I did the wireless AP function on that device and only use it as a modem.   If anyone has experience on using the Netgear Prosafe layer 3 switches as the router in the network and knows their quirks, let me know.  I have the opportunity to pick one up in the next couple days at a reasonable price unless I get feedback that this is not a good idea.

 

I am sure that my blithe ignorance is making all the people who have real world experience shudder.  That is why I am putting this out there.  I would appreciate all the helpful hints and tricks for setting up communication between layer 2 and 3 switches with link aggregation.

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ikon

OK. No problem. There are lots of people here who can help.

 

The first thing is to distinguish a router from a switch. The classic definition is "switches connect like networks, routers connect unlike networks". I know, really clear, isn't it? :huh:  Basically, what it says is that switches link together networks, or network segments, that are using the same protocol. In this case we're talking Ethernet (TCP/IP). Routers can link like networks, but their big strength is to link unlike ones; for example, connecting an Ethernet network to a Token Ring network. I'll pause here for a second while the old-timers among us clean up the Coke they just snorted out their noses after laughing at the mention of Token Ring. :) A more modern example might be using a router to link an Ethernet home LAN to an ISP via cable or DSL.

 

On a home LAN, you would not typically have a router installed (except for the one that links the LAN to the ISP). The Netgear GS748T will NOT replace the DSL modem from your ISP if you disable the DSL modem's router function (which is basically known as turning the DSL modem into a transparent bridge). For that you need a router -- a switch is not a router. One way, and I think a very good one, to replace the routing feature of your DSL modem is to use a software router such as Untangle (the one I use) or pfSense. There are quite a few others. The catch is that these software routers require either a real or virtual computer to run on.

 

I'm not entirely sure that the IT guys at your wife's work gave you such great advice. Sure, they can connect, configure, and use the 2970g switches without issue using Hypertext -- they're used to them, and use them all the time. For a home user, I think a web-managed switch is a better way to go.

 

To disable the router functionality of your DSL modem: i.e. turn it into a transparent bridge, call your ISP. I've done that with a number of ISPs and they have all co-operated and given me the required info, albeit some were more co-operative than others. However, I think this is premature. I would first get your LAN configured completely before tackling your link to the Internet.

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oj88

A layer-3 switch may share certain features with a true-blue router but the former is missing crucial elements to route traffic to and from the public internet.

 

First of all, the Prosafe (or almost any L-3 switch of this category) will not do NAT (or PAT). Neither will it provide network security like a firewall or any sort of protection beyond simple IP filtering. What it is useful for is for routing between two or more LAN networks on different subnets.

 

That said, you will still need a perimeter router to do the dirty laundry while your layer-3 switch sits behind it in your LAN.

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Just Checking

Thanks for the info!

 

I did get the Netgear GS748T switch.  I picked it up for under US$100 delivered.  

 

To clarify, I do not necessarily want to disable the router function on my modem.  I was exploring that option in case the internet connection goes down or the router portion of this device fails (that happened to me before). 

 

I am also concerned that my ISP (Centurylink) has access to my entire network through their modem/router.  I found that out when they dropped the connection and I called their tech support for a reset.  They were able to tell me how many devices were currently on my network, what type of devices they were, the names I had assigned to the devices, and even software/files running on the devices.  I did configure the firewall for tight security and my workstations and servers are set up to deny remote access so I am not sure how they are able to get that information.  I want to be able to deny them access to that!

 

A layer-3 switch may share certain features with a true-blue router but the former is missing crucial elements to route traffic to and from the public internet.

First of all, the Prosafe (or almost any L-3 switch of this category) will not do NAT (or PAT). Neither will it provide network security like a firewall or any sort of protection beyond simple IP filtering. What it is useful for is for routing between two or more LAN networks on different subnets.

That said, you will still need a perimeter router to do the dirty laundry while your layer-3 switch sits behind it in your LAN.

 

I think I will start another thread to get more input on setting this up.

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