Suggestions and comments for my network design...

[subflava]

Hey guys,

I am in the process of proposing some new network switch purchases for my company. I'd appreciate any comments and/or suggestions on my choice of equipment and design principles.

First, here are the usage demographics:

1. There are currently ~75 employees in the company and nearly all (95%) are at the same site, on the same floor of the building.
2. There are about 150+ total switch ports in use
3. The network is totally "flat" with all servers, printers, workstations, etc. in the same /23 subnet
4. Currently, network performance is not an issue. We use typical office applications (Outlook, Word, Excel) and large file transfers are rare. Our internet traffic averages about 100kbytes/s during peak hours. I have most (don't have all because some of the switches are unmanaged) of the switches being monitored by MRTG and overall traffic usage is very low.


Here is a diagram of what I want to add to the existing network:
Diagram
(The 3 switches circled in blue are what I would adding. Everything else is existing equipment.)

The current layout is basically consists of the HP4000 being the "core/center" of the network (the network is totally flat so there isn't really a core). Everything is basically plugged into the HP and umanaged 24-port switches have been added as more ports have been needed.

My reasoning:

1. The design is simple. I'm simply using Gigabit switches in a dual collapsed core architecture. Right now I'm leaning towards going with the Cisco 3750G series with SMI software.
2. I plan on breaking the flat network into 2 VLAN's to start. I'll have all the servers in one VLAN and all the workstations in another. I don't know how much more room this flat network has to grow...figure might as well segment sooner rather than later when people start bitching about "slowness".
3. Additional port capacity will be added with additional 2950's. I'm not as sold on Cisco here. It is nice to eventually have an all Cisco network, but does Cisco really matter at the access layer? Seems Cisco is easily 2x the price of any other vendor here. Also, if you want to go Gigabit to the desktop the difference is even greater between Cisco and other vendors.

What do you guys think?

 

[spidey07]

I think that if you can you should buy just one big switch. Its cleaner, easier to troubleshoot/upgrade and all centrally managed.

And with the cost of gig ports dropping rapidly you could even look at gig to the desktop if you have the cabling to support it.

two vlans would work just fine - servers/clients.

generally when building nets I've found one easy rule "simple is always better". meaning limit the number of devices, don't go overboard on redundancy, only use features you really need, etc.

 

[subflava]

Just one big switch huh? Which one would you recommend? The 4000 series? Do you think I could get away with just one 3750 for now and get a 4000 when the user base increases?

Regarding the Gigabit to the desktop; Do you think it would be fine to use a vendor other than Cisco? Or would you still recommend going with Cisco at the access layer? I think the lowest end Cisco switch with Gigabit ports is the Catalyst 3750G which starts at around $4K for 24 ports. Other vendors are about $2K for 24 ports. Think the price difference is justified?

 

[spidey07]

I like cisco. They make pretty good products.

Yes, if you went cisco a 4000 with the latest layer3 engine would be a good fit (you said you had 150 ports in use. Cisco's retail price is a joke and you can usually get them for much less (try CDW or your local reseller)

Cisco is not the only choice of course, only what I'm most familiar with.

I'm not a big fan of using more switches than required...it just gets messy. one switch for each wiring closet...so if all of your cables are in one place - use one switch with plenty of slot space to last for 3-5 years.

On the gig to the desktop - its just something to look at and compare to a 10/100 solution.

 

[Goosemaster]

Originally posted by: spidey07
I like cisco. They make pretty good products.

Yes, if you went cisco a 4000 with the latest layer3 engine would be a good fit (you said you had 150 ports in use. Cisco's retail price is a joke and you can usually get them for much less (try CDW or your local reseller)

Cisco is not the only choice of course, only what I'm most familiar with.

I'm not a big fan of using more switches than required...it just gets messy. one switch for each wiring closet...so if all of your cables are in one place - use one switch with plenty of slot space to last for 3-5 years.

On the gig to the desktop - its just something to look at and compare to a 10/100 solution.

Intersting that you should mention it. I am a student right now, so i probably ( ) don't know anywhere as much as you guysm but here i go:


I recently saw a study that touted that 10Gb/s connection to servers actually reduced stress on the network. Because the connection was so fast, requests were taken care of so muc faster. Obviously 10Gb is faster, but I had not realized the performance increases with even small requests.


subflava, maybe this is what spidey is getting at, although from what you posted, performance is not an issue(problem) right now.

Also, do you minf explaining the "dual collapsed core" architecture?

Would that cisco switch be there for redundancy with the HP? If so, where would the redundancy come into play? I don;t understand what access level of istribution level switch can offload to the cisco.

Assuming that the Dell and the "PIP" as your distribution switches, shouldn;t they be the ones that interface into both the core, and backup core?


Thanks

 

[subflava]

Also, do you minf explaining the "dual collapsed core" architecture?

It's basically just a variation off of Cisco's ideal 3-tiered network design with a Core, Distribution, and Access layer. The main idea with a collapsed core is that you combine the Core and Distribution layers into one physical device/layer because your network isn't big enough to need all 3 layers. You end up pluggin Access Layer switches directly into your core network. I'm not going to bother summarizing their model here, but you can check out this link to get an idea:

Cisco Campus Network Design

Would that cisco switch be there for redundancy with the HP? If so, where would the redundancy come into play? I don;t understand what access level of istribution level switch can offload to the cisco.

If you're referring to the 2 identical Cisco switches I have in the picture, they aren't there for redundancy with the HP. They're there to build structure into the network which has *none* right now. The HP would just serve as an access layer switch in my picture.

The reason I put 2 switches in the core is so they can be redundant. Spidey is saying he thinks it's better and simpler to just use one Cisco 4000 (or something similiar) at the core instead of having 2 switches and worrying about setting up L2+L3 failover between them.

 

[spidey07]

yep.

one switch, dual sups and power supplies. you're all set.

no messy spanning tree loops. no messy routing between switches. one switch, one router. Networks of this size scream "single layer3 switch"

 

[gordita]

Originally posted by: spidey07
yep.

one switch, dual sups and power supplies. you're all set.

no messy spanning tree loops. no messy routing between switches. one switch, one router. Networks of this size scream "single layer3 switch"

I abso agree with spidey.
one switch with redundant MSFC2's and 10/100/1000 TX blades is all you need.

I recently attended one of cisco's seminar where they said that the 6500 catalyst switch series is going to be around till 2014 as per plan and also saw a host of modules they will come out with for the 65xx.
we only use 6506's on our network and you have no idea how happy it made me to know that my SLA's are all going to be ok for the next 10 yrs!

on the same token, I have to admit that I love 3Com products.
I use them for SOME of my layer-2 stuff and they are just wonderful for simplicity, management, price/ports and innovative as well.

 

[subflava]

we only use 6506's on our network and you have no idea how happy it made me to know that my SLA's are all going to be ok for the next 10 yrs!

Curious...approximately how many total ports are on your network? I'd love to play with a Cat 65xx, but kind of hard to justify for a 75 user network

 

[cmetz]

Were it me, I'd get 4 Dell Powerconnect 3348 switches and stacking kits, stack them into one big virtual switch, and be done, cheaply. Modular switches are better, definitely, but the cost difference is pretty steep. The four switch scale is nearing the threshhold where modular can be worth it, since subflava only really needs three switches and the fourth is for room to grow, he should be okay on the stackable side of that threshhold.

In any case, one big switch or stack vs. a bunch of homogenous switches will save you tons of pain. Combine and centralize here.

For L2-only, Cisco's way overpriced, and it's just not worth the difference. When you start getting into serious routing features (L3) is when you should consider spending the big money.

 

[gordita]

Originally posted by: subflava

Curious...approximately how many total ports are on your network? I'd love to play with a Cat 65xx, but kind of hard to justify for a 75 user network

I run a campus topology spread over 5 buildings about 1/2 mile apart with each bldg serving 300-500 ports..approx.