nanog mailing list archives

Re: Anyone using uvlan out there?


From: Matt Palmer <mpalmer () hezmatt org>
Date: Fri, 14 Sep 2007 13:03:50 +1000


On Fri, Sep 14, 2007 at 12:33:03PM +1000, Steven Haigh wrote:
Quoting Matt Palmer <mpalmer () hezmatt org>:
On Fri, Sep 14, 2007 at 07:35:26AM +1000, Steven Haigh wrote:
  2. It doesn't require licensing

Plenty of VPN products out there are FOSS;

Yeah - I wasn't too sure about this either. I haven't seen any VPN  
software that requires licensing in years. I didn't know anyone still  
required this?

There's plenty of lots-o-money VPN products out there; presumably that's
what they're talking about.  The problem is that the statement "uvlan isn't
a VPN because it doesn't require licencing" is a ridiculous statement,
because you don't have to have a licencing requirement to be a VPN.

  3. It is much simpler

Simpler than what?

Routing?

Simple is in the eye of the beholder.  Switched ethernet networks have their
complexities that routed networks don't...

  4. It operates at Layer-2 (Ethernet), VPNs generally operate at
Layer-3 (IP)

Generally, perhaps, but it's not a requirement of the term "VPN" that it be
an L3 transition.

     Layer-2 applications like gaming can't be supported with
Layer-3 tunneling.

Plenty of games can successfully use IP.

I was thinking more the case of joining lans. Obviously its not a  
solution for all causes, as anything with more than 5-10 nodes per  
site and more than 2-3 sites would get pretty ugly. I think a nice  
thing would be for things that can ONLY use a local LAN due to either  
software or developer restrictions.

Well, obviously.

From my understanding, this software is pretty much acting like a
bridge, but with endpoints over a routed IP network.

Has anyone actually used this? Thoughts? Criticisms?

I haven't used this particular software, but I've used OpenVPN (software of
the Gods, by gum) in it's L2 mode, and it's OK as long as you observe all 
of
the usual restrictions on LAN-like traffic over a low-bandwidth,
high-latency link.  Most things that need to use Ethernet assume all sorts
of things that just don't hold over the Internet, and it causes some 
painful
hassles.  But, engineered properly, in the correct circumstances, it can be
handy to bridge two or more segments over a routed network.

I've used a lot of VPN stuff in the past, but I've usually always  
ended up doing it on a router, then had to NAT over it and all sorts  
of nasty stuff. I think this is a nicer solution if it could be  
implemented right :)

I don't think you quite got my point -- you *don't* need uvlan to bridge
Ethernet segments over a routed network; there are other products which will
do the same thing.  As I said, I've used OpenVPN to do this job, and my
experiences are given in that block of text you quoted.

A criticism of uvlan in particular is that I wouldn't trust my network
security to people who sound so clueless.  Their derision of VPNs, as you
quoted above, shows either a lack of sense or a blind hatred, using libpcap
in this situation gave me some chuckles, and their "What algorithms are
used?" page scares me a little.  I'll stick with OpenVPN, myself.

I think it's come about of a case of wanting to do stuff that won't  
work properly over a routed network (xbox games etc) - however could  
be nicer for a lot more things.

XBox games don't work over a routed network?  Please tell me that XBox Live
isn't just a giant uvlan install.

- Matt

-- 
When the revolution comes, they won't be able to FIND the wall.
                -- Brian Kantor, in the Monastery


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