Network switch redundancy ideas needed!

[Ypnos]

Hi folks

I have an interesting question

I'm after creating a network with some basic (i.e. cheap!) redundancy failsafe. By that I mean that if a network switch fails, I would like keep network continuity going. I've been thinking about something like 2 switches in parallel, but I don't know much about network topology.

Any ideas? Thanks!

[Moby-Dick]

how large is the network ?

I dont think you are going to be able to do it that cheaply as you will need multiple nics on each server that are capable of being teamed.

[Ypnos]

Well, it's an 8-port switch which is probably full. So say maybe 4 PCs.

If I take the word "cheap" out of the equation, how would it be done?

The main problem is power supply failure (more like some numpty unplugging it). Is there a dual power supply network switch, maybe?

[Moby-Dick]

there are but not too cheaply. Why not get a little UPS instead to power the switch ?

Back to the network side of things ,in addition to having teamed NIC's you'll need a pari of switches that support Spanning Tree Protocol

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

SO it'll need to be some form of managed Layer 2 switch

somethign like this ?

http://www.dlink.com/products/?pid=423

[Ypnos]

OK, got an update. Money is no longer an object but a simple solution is very much preferred.

The UPS idea has been considered, but there's nothing to stop someone unplugging the UPS from the switch. There's also a problem with people unplugging network cables too, which is why some redundancy is also needed.

If I can take some reasonable steps to give it some robustness, I can tell them their network has gone down due to user stupidity hehe

[Moby-Dick]

wrap the cables in barbed wire - should discourage them

are these desktops or servers you are trying to cable ?

[Ypnos]

wrap the cables in barbed wire - should discourage them

are these desktops or servers you are trying to cable ?

Not a bad idea! lol

There is 1x Proliant server, several terminal servers and maybe 4-5 workstations dotted around a 3x4 mile site.

Looking into your D-Link suggestion atm

[strike-down]

I dont know of any personally, but maybe someone else might. Try finding a network switch that also has the option of being powered by PoE?

[Ypnos]

Just had a thought! There are a lot of terminal servers, which don't have the ability to have network cards (as they are basically network switches for RS232 comms) and only have 1 RJ45 plug...

[mycarsavw]

Netgear make a few PoE switches.

I've stuck this over the power switch for the UPS - works wonders and has never been unplugged by mistake yet.

[Moby-Dick]

Just had a thought! There are a lot of terminal servers, which don't have the ability to have network cards (as they are basically network switches for RS232 comms) and only have 1 RJ45 plug...

Thats not going to help you sounds like a single point of failure right there. I suspect you will have to try some more cunning methods of user education.

[tfboy]

What you need is two L2 managed switches. These need to be configured to have spanning tree enabled so you avoid having loops on your network.

As you have workstations and TS devices that only have a single network point, the best you can do is spread them across the two switches.
i.e. PC1 on Sw1, PC2 on Sw2, PC3 on Sw1, PC4 on Sw2, etc.
That way, if one switch fails or someone unplugs it, only the devices connected to that switch will be affected.

Last point, you'd need to have a connection between the two switches so that PC1 connected to Sw 1 can talk to PC2 connected to Sw2. If there is a lot of traffic, you may need more than one 100Mbit or 1 Gbit connection between the two switches in which case you also need to look into trunking, i.e. LACP / 802.3ad. But that feature set only tends to be available on more expensive managed switches.

I can do a little drawing if you need to illustrate what I mean.

[Jay]

There's also a problem with people unplugging network cables too, which is why some redundancy is also needed.

I honestly think that stopping people pulling the cables will be the best way to sort this. Who is pulling cables and why?

[sys-req]

3x4 mile site

That's pretty big, you do know the limit for cat5 is 100 metres

[Ypnos]

Netgear make a few PoE switches.

I've stuck this over the power switch for the UPS - works wonders and has never been unplugged by mistake yet.

Been there, done that

I can do a little drawing if you need to illustrate what I mean.

Am I right in thinking that it's just 2 switches in parallel?

I honestly think that stopping people pulling the cables will be the best way to sort this. Who is pulling cables and why?

Contractors and there are so many of them that it's hard to know who does it, why and when

That's pretty big, you do know the limit for cat5 is 100 metres

Yep, which is why we have fiber optic for the longer stretches

[Jay]

That's pretty big, you do know the limit for cat5 is 100 metres

I think maybe they are connected by either MPLS or IPsec or fiber