I generally prefer VLAN routing, as it gives me the ability to have more flexibility and control over the network ports. It gives you a one size fits all configuration, so a single layer 3 point to point port has the same general configuration as ports you use for a multi-port vlan, and le lets you move the physical port of of a layer 3 ptp connection to another switch in your stack... But then I have operated a number of networks where you have arbitrarily large numbers of switches, and lots of redundancy, but once I became comfortable with vlan routing, I configure all of my networks this way, even at home. This is really handy when you have failover ports from a offsite location that are configured for separate building entry, and you have your core switches spread across the physical space. When a big disaster strikes a facility and takes down a couple of isles, it is handy to have your redundant core gear spread across some distance, so hopefully half of it remains up. But the bottom line is that a port is a port on the outside, so picking one over the other doesn't affect the physical wiring, it is more of a choice on picking flexibility over hard configuring a single port. I suppose there could be some advantage to port based routing as well, for example if you have a failover event, and you need a port to go down to trigger failover because of some feature your failover requires... But the best examples of that I can think of are not ethernet protocols, so it is more of a guess than a real example.
I like to have all of my layer three configurations consistent, and sometimes a new application comes along that requires a second vlan on a port. For example I have some access equipment that I support, and the proprietary SFP's are $2500 each. So rather than spend $5000 to have a trunk AND a management interface, I spend $2500 for a single port, and configure trunking for the access paths, and set the port-native access vlan to the management vlan.
I say all of this from many years experience running Cisco based networks where I use trunks everywhere I might have more than one logical network path, and the physical speed is much greater than the speed of the normal traffic. I just got my LB6M today, and I have not yet had a chance to dive into this aspect of configuration yet, so I could easily change my mind.
I didn't always prefer VLAN routing over port routing. But that was only because I started out with port based routing before the vlan standards were developed, so port layer 3, and port bridging was pretty much all I knew back then. The first time I stepped into a really large environment, the advantages of keeping all of the layer 3 on VLANS seemed elegant to me, and it is simply how it is done in many environments for many reasons. You CAN mix the techniques, but anytime you mix configuration techniques, you increase debug time, and create complexity.
I saw one blog from someone that works for a company that writes network monitoring systems, and he went on and on about how his network has no vlans, and never will have a vlan, and how vlans make things harder to debug, harder to understand, and in his 20 years of experience he never found a use for a vlan. The blog comments were divided with lesser experienced people thanking him for his words of wisdom, and enterprise network experts that could rattle-off endless reasons vlans were important and made things easier to debug. The point here is that once you learn how to use vlans for everything in your switch gear, AND layer 3 devices, you should find that configurations can scale much easier, and many network configuration design changes can be made from your desk without moving a lot of wires constantly, so your patch bays stay cleaner, and your knowledge of how the network goes together is easier to document and support.
And a final treason is it allows you to entertain self-configuring designs. The hospital network I ran had ports that configured themselves after you plugged into the port. So any ethernet port anywhere was set up for anyone to use it. The port joined the vlan appropriate for your machine, and if you had no business in the port, or were a guest, you were handed off to a captive portal vlan. It does not get more elegant than that. And if you have thousands of switches, 10's of thousands of ports, and rigid configuration change management procedures, elegant solutions are a godsend.
Yes, learning the ways vlans can be used is some work, and may seem like overkill for just one switch at home. But it is easy (once you learn it) scalable, flexible, and can make the difference between a network admin earning 44k per year, and being a network expert making $150k.
I'm sorry if I come off a bit opinionated. I /am/ very opinionated. But I have also been building networks for some 30 years, some really large, and some really small. Vlans don't make sense everywhere, but they are used in surprising places. Millions of people have them in their homes, as many ISP's use them to split Internet, voice, multicast video and management networks
Sleyk, this is what comes out when I scream like a gorilla...
