L3 switch vs. router on the bounds of IPv6 network

Question

Consider a typical home network of say ~20 devices. Let's say I want to make it a IPv6 only. I want to do it with only gigabit-capable devices. I can do that through a router or an L3 switch.

Let's take these two as an example:

• 5 gigabit port router (e.g. http://routerboard.com/RB2011iL-IN)
• 24 gigabit port L3 switch (e.g. http://routerboard.com/CRS125-24G-1S-IN)

Assume IPv4 is not used and features such as VPN tunnels are also not important.

Are there any obvious issues with using L3 switch instead of a router in this scenario? E.g. lower security, lower throughput, etc.

To phase the question differently - why would you use one or another in similar scenarios?

Or to phase differently again - what are the scenarios for most people (residential or very small business users) that would require one or another or where picking one or another would be superior?

Edit:

To clarify, this is a new setup and I'm looking at two options:

a) The standard inside network <-> dummy switch <-> router <-> internet, where all devices are connected to a dummy switch and the router is playing a firewall role

b) The router-less inside network <-> L3 switch <-> internet, where devices are connected to an L3 switch that is at the same time playing a role of a firewall

Option a) is both more complex (two devices to administrate) and more costly (need to buy both a dummy switch and a router). Option b) is potentially less secure and could have other cons (that's what I'm trying to figure out).

Since this is a home / small business setup, I'm not interested in anything except the above, so NAT, VPN, other WAN-type connectivity options, BGP routing, etc. are not something I'm looking for. I.e. it's pretty much as bare-bones setup as any other residential customer - I just need to be able to connect to the Internet and have standard security.

Specifically, on the page for the L3 switch I linked to I found:

• RouterOS gateway/firewall/VPN router with passive cooling

So it should support all I need (and more), but then again I'm wary of the marketing and looking for some input about this. Most importantly, whether others have a similar setup (while preferred, absolutely not restricted to the one I linked - just something in the similar price range, e.g. up to $250 or so) and some facts about why the setup is good or not.

To clarify even more, I am leaning towards the L3 switch setup because it's simpler in my opinion. I am trying to figure out whether going with L3 switch has any obvious deficiencies that I would want to avoid, most importantly from security and throughput / latency standpoints.

Answer 1

Since this is a home network, although a large one, I would counsel a router as being more versatile. A router can do NAT, QoS, Voice gateway, access control lists (security) and more, while a switch usually cannot.

Another difference (might not apply here), is that L3 switches do not offer the same WAN-type ports (T1, T3, etc.) that a standard router does.

The L3 switch will act like a switch when it is connecting devices that are on the same network, and like a stripped-down router when connecting externally. In general, you want to use a router when most of the time the device does routing. Likewise, you want to use a switch when when most of the time the device does switching. In other words, if one of the main purposes of the device is to connect externally, use a router. If its main purpose is to connect between local/internal devices, use a switch.

The specifications for your L3 switch includes a firewall, but I'm not sure how good it is. In general a router has its own IP address(es) while a switch doesn’t. I would prefer a router for better protection against attacks coming from the Internet. Routing software knows how to deal with different IP packets, such as ICMP and others, but switches don’t.

As regarding future expansion, multiple routers can be connected together as a network, but not switches.

The advantage of the L3 switch is that it will be much faster on switching packets, but the question only you can answer is whether you need that speed.

In all, for security and versatility I would advise using a router for a home network.

Your linked router is defined as "a low cost multi port device series" for $99. Given that the L3 switch you are considering is priced at $189, you could afford a better router for the same price. I would also counsel a router that supports the DD-WRT firmware with easy installation, just in case you would need more functionality in the future.
_{(Note : Product recommendations are disallowed on this forum.)}

Answer 2

CRS125-24G-1S-IN is not only switch, this is switch with router, exactly with MikroTik RouterOS Level 5. So yes, it have firewall and many other things...

Answer 3

There are a couple of problems with some of the answers provided. First and foremost we have to understand what a layer 3 switch is, and what a router is.

Usually a router (in the U.S.) is connected to an ISP using a variant of PPP (specifically PPPoE). The router takes a routed protocol (TCP or UDP) and passes it to the provider network directly. Then the provider network uses a routing protocol (OSPF, IS-IS, or RIP) to route the routed protocol.

A layer 3 router is making use of MPLS (Multi-Protocol Label Switching) to switch packets in the router instead of using the routing engine. This means that the packet skips the routing engine and goes directly out a physical port.

The catch is MPLS is only useful if your provider is using it, and you have multiple networks (think 254 devices per network in 254 networks).

What you are attempting to do will provide no net benefit. You are essentially complicating your network... because you can.

An L3 switch is NOT just a switch and a router in one box. An L3 switch is a router runnning specific software that makes it compatible with protocols being used by other L3 switches it is connected to.

I've worked with Layer3 switches. I'm currently a Network Security Engineer at Level3. I've worked for TWTelecom and Reliance Global Com as a network engineer. Let me know if you have any other questions.