Holy Teredo! Vista Networking Rocks

Lloyd Ketchum – YAB, “Yet Another Blog”

Holy Teredo! Vista Networking Rocks!

you ever see the pop-culture poster of the WWII GI holding up a cup of
coffee with the caption that reads, “Have a Nice Steaming Cup of STFU!”

is exactly what I think of when I reads blogs, forum posts and tech
press articles waxing on about the alleged problems with networking
in Windows Vista.

Networking is about more than simple email and web surfing – it is about communicating visually.

haven’t read any down to earth tech blogs or forums that offer much in
the way of tested information, or that which reflects any experience in
networking with Windows Vista. I have read a lot of lay opinion, and I
thought it might help if people were made aware of some of the
not-so-technical tools they might use to get a lot more out of Windows
Vista and their home, or small office networks.

Part of me wants to counter such comments with jokes, but I know it
won’t help – so aside form the one leading this post off, I’m going to
instead try and offer some information that may help users at least
understand how to get the most out of Windows Vista’s networking
abilities really quickly. I’m not going to focus on a lot of dry
technical detail, but instead, show people how they can use some simple
tools and settings to diagnose their networks, associated equipment and
move beyond the hype and what I assess to be baseless criticism. A
couple notes of caution: Be sure to read as much as you can about the
subjects I am addressing here. If you must, or feel you must update the
firmware on any device you have, please do so with extreme caution –
many smaller, older routers have very small amounts of flash memory,
and if one has applied manual settings of any kind, there may not be
enough free flash memory available in order to write a configuration
file to the router, parallel to an existing image [into temp space].
This lack of free memory is why so many people “Brick” or ruin an
otherwise normally functioning router. Also note that if one does
“Brick” a router, no amount of factory reset attempts will work –
again, owing to insufficient memory being available.

I assess
that Vista is the first and best step into a new world of continuously
connected systems that is by design, as easy to use as it is flexible.
I also assess that nearly all people are as interested in doing more
than basic web surfing and email as I am. I do not accept that most
people are only interested in these few things – as so many in our
press continue to insist. Connected computing devices are about much
more than basic, plain text email and web surfing of largely static
content. Vista and the ecosystem around the Windows Platform are about
so much more – they enable very rich experiences that are intended to
include participants and content from many sources, simultaneously –
all mixed and mashed together. Vista’s networking capabilities provide
for this and they extend well beyond the ability to connect to wired
and wireless networks quickly and reliably. Vista is about enabling not
just video, but shared video; not just publishing, but collaborative
work; not just communications, but unified communications, where video,
voice and data are all combined at once to strengthen and enrich not
just how, but what people communicate. Vista is not just about media
consumption, it is about creation.

Using and
Understanding Microsoft’s Internet Connectivity Evaluation Tool – Know
your Router and How Vista Can Communicate with it.

Vista, networking is about doing things on networks easily and safely.
This has to begin with users of any skill level having the ability to
understand where they and their systems are located, relative to other
systems and how they are going to reach one another – the information
supporting that has to therefore be visual and the connections have to
be automated. To begin with, people have to have an understanding about
the environment they are in – what capabilities their network can
support right now and how it can be made to let Vista loose to do its
best work. Large numbers of computer users have one form of broadband
or another – a continuous, or instant-on connection to the Internet via
an ISP. Many of these users have a small home, or small office router,
which they use to share their connection to the Internet with more than
one computer at a time. Most people can use the simple set up utilities
provided by the manufacturers of such routers; however, fewer
people understand how vital a role their router plays in what they can,
and often cannot do across the Internet. Even fewer people understand
how Windows Vista can communicate with and take advantage of what more
modern small office and home routers can do. To help people, Microsoft
makes available an on-line test tool they call the “Internet Connectivity Evaluation Tool.”
This evaluation tool uses a small control that users can approve and
run within Internet Explorer. It is designed to perform a series of
tests on a home or small office network router and report back on the
availability of features supported by the router. If all features are
supported, users can be reasonably certain that their network will be
able to easily and automatically support a wide range of exciting and
useful activities across the Internet and other public networks. Such
activities include many things people are familiar with, like video
conferencing, video chat and on-line games, but others that are equally
useful, may be less well known – Vista’s new Meeting Space for on-line collaboration, remote access, and remote assistance are only a few examples. Before
I go any further, I want to point out that people can access fully
capable routers for very little money and as an example, I put together
a small test network using a home router from D-Link [
EBR-2310 Ethernet Broadband Router] that cost less than twenty-three dollars [USD]. Using
Microsoft’s on-line Internet Connectivity Evaluation tool, I was both
surprised and pleased to note that the EBR-2310 fully supports all of
the features that would enable Windows Vista to use all of its new
networking capabilities [image of my test network’s results here].
In addition to basic Internet connection tests, the evaluation tool
tests to see what kind of NAT, or Network Address Translation a router
supports. This is important, because not all NAT devices are the same,
and in order to use some of Vista’s features, IPv6 embedding, for
example, Cone NAT (explained here)
support is needed instead of symmetric NAT [Windows Meeting Space use
across the Internet uses Cone NAT to support IPv6 inside IPv4 packets]
to allow applications automated, yet safe, access to Internet
resources. The next text determines how well a router supports ECN,
Explicit Congestion Notifications. This is perhaps the most important
feature a router must support in order to allow Vista to run at its
best across a network. To understand why this is important, one has to
understand how TCP works. TCP is like a long water hose, and it works
best when it is consistently filled. When it is not, there is packet
loss, like the loss of consistent pressure in a pipe – causing air
pockets to form and a hose to spit and shake. ECN helps by providing
notices of congestion and Vista uses these to dynamically size its
window scale up or down to make sure the pipe remains full and the flow
is consistent. This helps ensure faster downloads and more reliable
end-point connections. To explicitly enable ECN support in Windows
Vista, do this: Open a command console as an administrator and enter
the following command and restart the computer,
netsh interface tcp set global ecncapability=enabled

the evaluation continues, more areas are tested that assess a router’s
ability to communicate how two computers can scale together. As stated,
Vista can scale dynamically, but in order to do this correctly, both
the Vista computer and remote computer have to scale together. The TCP
High Performance specification, [RFC-1323]
stipulates and explains how this works and compliant routers will be
able to allow Windows Vista to scale optimally. The next test
determines how well a router supports UPnP, or Universal Plug and
Play. Vista along with Microsoft’s new “Rally” technologies,
support an extension to UPnP called UPnP-x – an extensible addition to
UPnP which network and device manufacturers use to add intelligence to
layers using Link Layer Topology Discovery protocols – more on that in
a moment. There are going to be people out there that will tell
users to turn UPnP off on both their systems and networking equipment
and they base this recommendation on concerns about security opposite
very early builds of Windows XP.
Well a lot has happened since
Windows XP was shipped and I do not know of a single reason why UPnP
should be turned off in Windows Vista, or XP with SP2. I do however
know of many reasons why using UPnP and UPnP-x are very important to
computer users – Vista can communicate with and control such devices
and adjust them according to applications being used – Vista can also
configure itself to use such devices without user intervention of any
kind and emerging products like Windows Home Server can use UPnP to
configure routers for remote access. I personally use and enable UPnP
and recommend others do the same. The last test performed stresses the
router’s ability to sustain multiple simultaneous connections [80 to be
specific]. This is important to see how well a router can support
multiple computers running multiple connected applications – many of
which use more than one port and many more sockets. Most simply, how
well can many people on the same shared connection, use many programs
that connect to the Internet at the same time?

If one’s router,
like my own test router [a cheap’o to be sure], passes all tests, one
may be reasonably sure that Windows Vista will be able to use some of
its most exciting features across the Internet. Things like Remote
Assistance, Remote Access, Video Conferencing, On-line Meetings,
On-line Gaming, Shared Desktops and White-boards, will all be better


Perimeter Router
D-Link DIR-655 > Xtreme N Gigabit Router

Never use a router’s built-in switch! Never! Ever! Ever!

Unmanaged Switch [to be placed behind the router above]
D-Link DGS-105 > 5-Port Gigabit QoS Desktop Switch

Wired Ethernet Network Interface Card
D-Link DGE-560T PCI Express Gigabit Network Adapter

Inside the Network

Now that we have a better understanding about how one may best use
connections to the Internet, we’re going to explore how to see and
manage internal networks with Windows Vista.

Windows Vista, as
most have by now heard, has an entirely new networking stack, and
interfaces for accessing and managing networks and connections. The new
Network and Sharing Center
provides an easy to understand and use interface for all things that
are related to networking. One of the most important changes in Vista’s
networking is how the operating system manages network connections as
unique environments – where it stores and remembers unique settings
where desired. For example, when a user is at Home [a Private
network in Windows Vista] they are likely to want to share files and
printers with other home computers, but while the same computer is used
out in public, at an airport, hotel, or in a coffee shop, the user
would want to maintain a unique, and more secure networking profile
[called Public in Windows Vista]. When in Public
mode on Windows Vista, all network sharing is turned off and the
computer automatically operates in a stealth mode – concealing itself
from discovery. Vista automatically adjusts and stores stricter
Windows Firewall settings as well, further hardening a computer. When
users of Windows Vista make new connections they are offered a choice
as to whether they wish to save that network and its settings, or
discard them after they have disconnected. This prevents a lot of stale
and unused network settings from piling up – a condition that will
eventually prevent a Windows XP SP2 computer from being able to
re-connect to desired, or preferred networks. Vista does not have that

Using the Link Layer Topology Discovery Responder in Windows Vista and XP SP2, and the Windows Vista Network Map

By default, Windows Vista has support for a set of protocols operating under the LLTD, or Link Layer Topology Discovery specification. Vista implements these with two controls, the Mapper and the Responder, which are used to support Microsoft’s Rally
technologies as well as discovery and presence within compatible
networks and the Windows Network Map. The Network Map in Windows Vista
is available via a link in the upper right portion of the Network and
Sharing Center. Clicking this link, titled, “View Full Map” executes
a discovery and reporting program that displays the computers and
devices within the network – where LLTD compliant devices and computers
are present, they are displayed and mapped in relation to one another
and how they are connected – via wireless access point, for example.
People with mixed Windows Vista and XP SP2 computers can get an LLTD
“Responder” for WGA validated XP SP2 based systems here.
In my test network I have applied the XP SP2 LLTD patch to two systems
– one Windows Media Center Edition 2005 PC and a wirelessly connected
UMPC [Samsung’s Q1 (One of my favorite computers of all time)]. See the
figure below.

Test Network Map with Connected Windows Vista and XP SP2 Computers and Devices

What might not be entirely clear from the Network Map is that the
perspective drawn is from the Vista computer from which it is
executed. In the sample, LLOYD-PC [a Vista Ultimate laptop] appears in
the upper left on a wired network segment and from the map, it appears
to be closest to the Internet gateway and Internet traffic – it isn’t.
This reveals a weakness in the present networking map, but
interestingly and otherwise, the map is logically accurate. Note,
also, LLOYD-PC also has a wireless interface connected to an access
point that is connected to a switch, which is then connected to the
main distribution switch closer to the network’s perimeter. The
router, as can be seen, is isolated from the switch fabric. One can
also see that there is an Xbox 360 on the network and it uses a wired
connection on a switch of its own. Network printers, while the appear
in the map, can’t be integrated to it, because the model used does not
support LLTD [in this case, an HP 3210 network printer]. While not
physically accurate the map is still useful and will become more useful
as devices make use of Microsoft’s Rally technologies. Rally, an
initiative first introduced at the WinHEC in 2006 and featured most
prominently at WinHEC 2007, extends the LLTD and allows hardware and
software developers to attach, distribute and display, not only much
great amounts of information about devices, but custom images as
well. Rally also provides for automatic discovery and configuration –
reducing network connection efforts to a point and click process.
Demonstrations of Rally enabled D-Link hardware were featured at WinHEC
2007 during one of the keynotes and the technology was very warmly
received. I personally think Rally is one of the most important and
innovative technologies to emerge in support of networking in a long
time. The D-Link hardware I have recommended above uses and supports
these technologies.

Using the Link Layer Topology Discovery Responder in Windows Vista while Joined to a Domain.

The text books tell us that the Network Map in Windows Vista is only
available if the computer is in a Work-group and not joined to a
Windows Domain. This is sort of true, but not accurate. Business and
Ultimate editions of Windows Vista – those that can join domains, also
have policy object support and local machine policy management tools.
One may use these, or Windows Domain network administrators may use
them to turn support for the network map back on. There are two policy
objects, one for the Mapper and another for the Responder. These
policies may be adjusted easily – be sure to check with your network
administrators regarding the application of these, or any policy.


While we have only touched on a few things new in Windows Vista
networking, I think they are some of the most important for small home,
or office users. There are both great tools in Vista, as well as new
technologies in general that make networking easier and more powerful
than ever. Windows Vista is the key, the center of these technologies
and with it, what we do with network connections is the most exciting


Lloyd Ketchum – YAB, “Yet Another Blog”

I feel bad for the Windows Vista team in general and the Ultimate team in particular. They built some

July 3, 2007 12:53 PM


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