1

Which type of network hardware devices (Router vs Swtich) you would use as a campus distributor in a structured cabling project?

It seems logical to use switches as building distributor, we can implement VLANs to isolate broadcast traffic between floors and use a router for the communication between them.

But what about campus distributor? If we have two buldings we can use the same technique to isolate traffic between buildings but we still need a router to route traffic between them.

Does it make sense to have a router as a campus distributor in each building? Is there any golden rule or it depends on the project's type?

JDL
  • 111
  • 2
  • Not sure what you're trying to achieve. Do you need a layer 3 connection between buildings or do you require a layer 2 tunnel (i.e MPLS, I2tp etc). How many IP feeds do you have at each site? Are the circuits physical or virtual (psuedowire). – Brett Levene Nov 22 '16 at 18:50
  • I am just researching in network cabling standards and I want the opinion of somebody how has built some project from scratch. In my mind the case network will have 3 building nearby with phisical connection and around 300 ip each. – JDL Nov 23 '16 at 08:54

1 Answers1

0

It is very difficult to give you a recommended topology because there are a significant number of permutations that affect that decision. What I can give you are some very high level pointers that may help you out.

1). Where ever you need to perform IP routing, you will definitely require a layer 3 device. This doesn't necessarily mean a Router, you could quite easily use a layer 3 switch (which is a very popular option because of the additional flexibility it gives) or a Firewall (if you can administer routing tables on that device/server).

2). If you decide to split VLANs across multiple sites, bear in mind that network performance starts to degrade once you approach around 500 devices per subnet (mostly due to the volume of Broadcasts, and although this isn't a rule per se it is a good suggestion).

3). If you have multiple IP feeds located in different buildings, you will need to check if routing resiliency is required (protocols such as VRRP and HSRP). Again, it is impossible to say what is required because we do not know the complete picture especially concerning how circuits are presented by your ISP.

4). If you have a physical cable running between buildings that you control, there is no reason why the end devices cannot be layer 2 switches. If all three buildings are connected via switches, this would give you a flat network architecture where redundant links are managed by something like RSTP/MSTP.

5). If you have server farms or data centres at each site, a layer 3 switch would be useful in this topology because to could achieve point 4 whilst removing the need to have a separate core layer that does all the routing for the campus.

I've linked Cisco's take on Campus networks, although judging by what you said I think it could be simplified somewhat.

Links:

http://www.cisco.com/c/en/us/td/docs/solutions/Enterprise/Campus/campover.html

Hope that helps!

Brett Levene
  • 786
  • 6
  • 9