I can tell you from experience, confgiuring with VLAN can be encumbering (we do it almost everywhere), and I don't recommend it for everyone. But having the ability to configure it when you need it is really usefull. For example, lets say I have two client off of one sector, and I want to run seperate DHCP servers per business subscriber, or per project. I route 1 VLAN to one project and another VLAN to the other. Or when I want flexible IP assignment, or need to minimiz giving full blocks, How do I kkep one customer from misconfiguring his equipment and taking out another subscriber? Give them each there own VLAN. How do I seperate traffic between them so I can give them their own customer queues, I give them VLANs. VLAN allows central routing deliverdd via VLAN. But many times its simpler to take the routing all teh way to the last hop to the subscriber instead. For exampel Routing allows redundant path decissions to be made, without thinking of the complex bridge conflicts. The lsit goes on and on. I have many reasons to route at many locations and many places to VLAN. I think the best solution is to have the flexibilty to be able to do either or both, when and where ever a need arises. But then management of it all gets a mess, when a million different things are gettting done. So the real question is not wether to route or bridge, it is "how do you track / document it all?"

Tom DeReggi
RapidDSL & Wireless, Inc
IntAirNet- Fixed Wireless Broadband

----- Original Message ----- From: "Russ Kreigh" <[EMAIL PROTECTED]>
To: "'WISPA General List'" <wireless@wispa.org>
Sent: Sunday, December 03, 2006 2:03 PM
Subject: RE: [WISPA] Routed vs bridged (again)...

I can't believe I am getting involved in this...

First, routing is not bad, or the best solution. Bridging is not bad, or the
best solution.

Network DESIGN is the solution.

A hybrid network DESIGNED by a competent network person will outperform a
pure bridged network or a pure routed network any day. PERIOD.

I am not going to go into the technical aspects of why routing versus
bridging is good, and bad. It all depends on what you are trying to
accomplish, what your customers are trying to accomplish, your market, your
competion, what equipment you are using, your budget, your staff's
experience, failover protection, outage isolation, QoS, Security, Mail, SLA
requirements and about 100 other factors.

Let me say this, I administer about 70 routing devices, ranging from Cisco
7206 routers, Cisco Catalyst L3 switches, down to Mikrotik 532's. I also
manage some pretty HUGE bridged segments on our network.

I've seen routed networks be brought to their knees, I've seen bridged
network do the same.
The difference in our case is that we DESIGNED the network.

We also have several dozen VLAN's on our network -- there is a misconception
that using VLANs means you are bridging - well, no. Its hybrid, and in the
end, it is ultimatly routing.

And again, public IPs versus Private IPs to a customer is a whole different
story, we have both on our network - it depends on what you are trying to

There is no need to give a /30 to every customer, there are other more
efficent ways of doing this.
With a /30 your using up 4 addresses, 1-Network Address 1-Router Address
1-Customer Address and 1-Broadcast address.

There is an argument that bridging is easy, yeah, until something goes
There is an argument that routing is easy -- until something goes wrong.

Many of you are die-hard routing people, many of your are die-hard bridgers.
That's fine -- but stay away from my network :-)

So, in case you missed the point of this email NETWORK DESIGN is the best


Russ Kreigh
Network Engineer
OnlyInternet.Net Broadband & Wireless
Supernova Technologies
Office: (800) 363-0989
Direct: (260) 827-2486
Fax:    (260) 824-9624

-----Original Message-----
Behalf Of Marlon K. Schafer
Sent: Sunday, December 03, 2006 12:41 PM
To: WISPA General List
Subject: Re: [WISPA] Routed vs bridged (again)...

----- Original Message -----
From: "Butch Evans" <[EMAIL PROTECTED]>
To: "WISPA General List" <wireless@wispa.org>
Sent: Saturday, December 02, 2006 10:44 PM
Subject: [WISPA] Routed vs bridged (again)...

On Sat, 2 Dec 2006, Marlon K. Schafer wrote:

It's a very high cost.  Why does every residential user need to tie up 3
ip addys?  How long can we keep handing them out like that before we run
into trouble again?  There is only so much nat that we're gonna get away

I give up...why does a residential user need 3 ips?  I never suggested
that they did. And I guess I don't understand what nat has to do with any

of it.

OK, what's the minimum number of ip addys that a routed customer HAS to use?

I thought it was three. Is it really two or four instead? Either way, it's

a waste of ip addresses.

NAT matters because it's the only way many of us would ever get enough ip
addys for every customer AND every device on the network.  For customers
that increasinly need two way communications NAT isn't a good option.

Then there's the CALEA crap.  How in the world is a person going to track
EVERY packet in his network?  And those doing NAT may well have to as ALL
customers behind a nat'd address show up as the one public addy. That's not

gonna help anyone find that Kiddie porn freak.  So what will we have to do
to comply? Don't know for sure yet, but I certinly think that it'll be much

easier to deal with the issue if every customer has a public ip.

No...not a requirement.  It's just a more scalable solution.

There are nearly 4000 (unfortunately not all mine :-) 100meg customers on
that network.

I don't want to argue this point, because I just don't have enough
information about the network.  I seriously doubt, though, that all those
customers are all on a single /20 network (which would support 4096
hosts).  Even worse, if there are routers there, too, it may need a /19
(which would accomodate over 8000 customers).  If they are not, take my
word for it...they are routed.

They are routed to the world at the isp. But they are NOT routed within the

network. They are vlan'd. Some isp's may have multiple vlans or some such
thing, but I'd be surprised at that.

I'm just saying that it's far less important than it used to be.

With the proliferation of worms being what it is, and most of them
spreading by broadcast to the local network?  You must be kidding...

Nope.  We block client to client communications at the ap (and hopefully
soon at the switch). The worms can only get sideways on my network by going

through the router, which under your theory will block them.

Also, we require all customers have a firewall and antivirus. In theory we
actually have several levels of protection in place against just such

OK, I've had enough fun poking at the religious right on the routed vs.
bridged debate.  The reality of the situation (as with so many things in
life) is that both are used and both do a better job if used in the right
places.  Right tool for the right job.  And EVERYONE's job is a different
one.  The isp has to be able to make smart choices for his network.  Talk
about all or nothing in either direction isn't really helpful in my mind.

How's that?

Butch Evans
Network Engineering and Security Consulting
Mikrotik Certified Consultant
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