This page is about setting up the critical services typically used to help data get moved to whatever location it needs to get moved to. This is part of the Networking section which may include other related technologies, such as monitoring network traffic. The network features page may contain information about services that use a functional network, while this section is more about making a network functional in the first place.

[#availnic]: Available NICs
This page is about determining the name of available NICs that are recognized and usable by the operating system.
[#netconn]: Network connections/connectors
Recommendation of WPA2 w/ CCMP (a.k.a. WPA2 w/ AES), and not older options

ZDNet's article: WPS “is Busted” mentions a problem with Wi-Fi Protected Setup. The article states, “older Wi-Fi security methods, such as Wi-Fi Wired Equivalency Privacy (WEP) and WPA (Wi-Fi Protected Access), with the built-in Temporal Key Integrity Protocol (TKIP) have long been broken.” That quote is a hyperlink to another article, Firesheep's Real Lession: Take Wi-Fi Security Seriously.

ZDNet's article: Don't assume WPA2 is more secure than WPA notes, “WPA is an industry standard that is based on the IEEE draft 802.11i security standard whereas WPA2 is based on the ratified standard so they?re essentially the same thing.” (The article goes on to mention some minor differences between the standards.)

Those articles suggest not using WPS, WPA, WEP, or TKIP, and do suggest using “WPA2 with Counter Mode with Cipher Block Chaining Message Authentication Code Protocol (CCMP), aka Advanced Encryption Standard (AES)”. However, with at least four security measures being historically defeated, the track record (of recommended Wi-Fi connection security methods) hasn't been good. It may be better to not rely on wireless standards for security, but to implement security using another technique, such as tunneling.

Broadcasting an SSID is okay

For a while, some people had recommended trying to “hide” a network by not broadcasting an SSID. Many devices (probably nearly all devices, and perhaps all standards-compliant devices) have a configuration option to disable broadcasting an SSID. Many guides have recommended using that option to disable the broadcasting of an SSID.

This text debunks that recommendation.

There are not really any substantial security benefits to hiding an SSID, for reasons that are about to be explained further. However, there are generally some benefits to broadcasting an SSID, go ahead and broadcast the SSID. Do not disable SSID broadcasts just because of the idea that it helps security.

ZDNet: How to keep Wi-Fi locations out of Google (referring to Google Street View cars) mentions, “finding an “invisible” SSID is trivial.” A guide to security wireless suggests turning off SSID. Others don't. TechNet: Non-broadcast isn't security notes, “A non-broadcast network is not undetectable. Non-broadcast networks are advertised in the probe requests sent out by wireless clients and in the responses to the probe requests sent by wireless APs. Unlike broadcast networks, wireless clients running Windows XP with Service Pack 2 or Windows Server® 2003 with Service Pack 1 that are configured to connect to non-broadcast networks are constantly disclosing the SSID of those networks, even when those networks are not in range.”

Technet Blog: Non-Broadcast Wireless SSIDs (Why hidden wireless networks are a bad idea).


Some places, such as entire nations, have had regulations about what type of encryption may be used. A well-known position is when a government has tried to limit the use of encryption.

In Germany, the opposite has been true: Slashdot article: German user fined for having Open Wi-Fi. There was some international opposition to this ruling. However, the opinions of people from other nations may be rather insignificant to the German court's authority to make a decision about the laws within that court's jurisdiction.

(This has now become a rather old comment, so presumably there might be some updates to that situation. Hopefully the law of this respected nation is not continuing to conflict with the designs of the international communities which creates the specifications of main Wi-Fi standards.)

Misc comments about Wi-Fi

Certain “channels” are used to connect. Basically, a channel is a segment of wireless spectrum. These spectrum sections do overlap with neighboring spectrums. With 802.11a, 802.11b, 802.11g, the spectrums were numbered 1 through 14. In America, spectrums 12 through 14 were not opened up initially. The recommendation was to use channels at least 5 away from Wi-Fi devices that use other channels, so the common channel numbers were 1, 6, or 11. spuder's answer to Mike's question on Wi-Fi says some of the remaining channels have since been opened up. (Wikipedia's article: “List of WLAN channels” discusses “channels 12 and 13” a bit further.)

Equipment that uses the 5GHz range, including many pieces of 802.11n equipment, may use some other channels. Wikipedia's article: “List of WLAN channels” provides details, such as mentioning Japan's use of some channel numbers within ranges like 7-16 and 183-196 which are not used elsewhere. (Japan also uses some of the channels that are used elsewhere.) The channels 7 through 12 of 5GHz spectrum have different frequency centers than the channels 7 through 12 of 2.4GHz spectrum. So, fully identifying a channel would involve more than just the channel number. In other areas of the world, common channel numbers of the 5GHz range may include some channel numbers in the range of 34 through 165. (This does not include every number. For instance, channels 140 and 149 are in the list of channels used for WLAN, and channels 142 and 144 are in the list but are not available in as many nations, while channel 145 isn't even in the list.)

spuder's answer to Mike's question on Wi-Fi provides a number of additional comments, including generally discouraging use of auto channel select (due to quality issues). comment posting about WiFi Channel 14.

Frequency Choice comment by Murot Eron describes based on what was economical.

Many people involved with “higher education” may have a connectivity authentication option that uses eduroam. (See: Wikipedia's article for eduroam, RFC 7593: “The eduroam Architecture for Network Roaming”.

Guides for connecting Wirelessly
Microsoft Windows Wireless Connectivty

Much of this may have been written/tested in Windows 7. Lots of details seem to be subject to change whenever Microsoft releases a new major releasae of Microsoft Windows, so expect that this guide may have some variations.

Information about using Microsoft's Wireless Connection Service
Applicability of these instructions

This guide covers some of the most common ways that wireless networks are used.

There are other options. For completeness, some of the other options may be mentioned here just briefly, although they might not be heavily covered by this guide. This is a guide to connect to the most common type(s) of network. So, this guide covers creating an association with an already existing “infrastructure basic service set” (“BSS”), or similar (e.g. “extended service set” (“ESS”). This guide does not currently cover making an association using an “independent BSS” (“IBSS”), also known as “ad hoc” mode, or “peer-to-peer” (sometimes abbreviated as “P2P”). That is another approach, which can have some advantages. However, many people may find that the approach of using an IBBS is a bit more challenging than using a pre-configured BSS. Perhaps for that reason, using an IBSS is a less common setup.

This guide does not distinguish between a basic service set (“BSS”), or an extended service set (“ESS”) which is basically a collection of individual “basic service set” devices connected via wired networking infrastructure, or a “wireless ditribution service” (“WDS”) which is basically multiple BSS devices that use wireless communications to communicate directly with each other. From the perspective of many devices that are commonly used by an end user, all of these configurations can be connected to as easily as a single BSS. Therefore, this guide simply refers to all of these types of configurations as a “BSS”, even for networks where one of the more elaborate terms may be applicable.

Available Networks

To see available networks, and to connect to one, follow these steps.

Get to the Connect screen
[#nshcwlan]: The fast way

The “system tray” (more officially known as the “message notification area” with some versions of Microsoft Windows) may have an icon that represents a wireless connection, such as five “reception bars” (vertical bars that increase height/length on the right side of the icon). Left click on that.

That is often the fastest way, although there are a couple of possible disadvantages to this method. One is that it requires the use of a rodent cursor, which is not always desired. Secondly, the icon might not exist. The network-related “system tray” icons can be disabled (or re-enabled) by going to Control Panel, “Notification Area Icons”, and “Turn system icons on or off”. (This may be unlikely, but still is a possibility worth mentioning.)

Going through network settings

Following are some approaches that involve using the “Network and Sharing Center” which is available via the Control Panel. (Further details about accing the “Network and Sharing Center” may be available in the section about “Network”-related Control Panel icons.) After getting to the “Network and Sharing Center”, choose one of the following:

The long way

In the left frame, choose “Change adapter settings”.

Select (highlight) the desired NIC. Choose “Connect To”.

The newer approach

Speculation: This is new to Vista and newer?

In the “Network and Sharing Center”, there is a hyperlink called “Connect or Disconnect”. This is between the top two rows of icons, and is to the right of the text that says “View your active networks”.

After doing this, any detected basic service set (“BSS”) which is broadcasting its Service Set Identifier (“SSID”) will have the SSID show up in the list. (In other words: the window that pops up will show any wireless device that is actively announcing its presence.) Choose the name of any desired network. Highlighting the network will show a “Connect” button. Also, hovering a rodent over the name of the network will show various technical details about the connection.

If no wireless networks are being detected, check some of the common issues with wireless networking.

Note: There are quite a few possibilties (especially when considering historical options which have been known to offer multiple ways of doing things), there are several possibilities that could go wrong. This section of this guide is not discussing things like incorrect IP addresses or a NIC that isn't seen by Microsoft Windows. This section does cover some problems that can prevent the card from being able to even see what wireless networks are available.

  • Is the client device out of range?
  • Is the wireless network circuitry on the end-user device being disabled? Often that is done to save power, or perhaps for security reasons. Especially if the comjputer is a laptop, check if there is a physical switch. If there is no such physical switch found, see if there is a software setting that indicates that the circuitry could be off, but is actually on.
  • Make sure the BSS is working. Do any other Wi-Fi devices work?
  • See if Microsoft's wireless network management software is being used, or another vendors. (See: (Not) Using WZCSVC.
Viewing information about saved networks

To see information about saved networks, go to “Network and Sharing Center”. In the left frame, choose “Manage wireless networks”. This shows information about networks that were previously used for a connection. The “Add” button can allow the creation of a new collection of information about a specific network. This is not the way to scan for devices.

[#nomswzcs]: (Not) Using WZCSVC

Even after Microsoft released some standardized icons, some vendors (at least Intel) have been known to continue to provide customized software for interacting with network hardware. Often, such customized software has not provided substantial and popular benefits beyond the software provided by Microsoft's software. There might be some noteworthy features provided by the vendor's hardware (speculation: integration with an interface supporting VPNs), although such features might be of interest for only certain people (like people who use VPNs). The practice of providing custom software is likely to continue for some time. Perhaps more companies will eventually decide to do things with standard approaches provided by Microsoft, or perhaps companies will keep trying to provide their customers with an experience which is more unique (and theoretically superior). In some cases, the computer should not run (or attempt to run) the vendor's custom software at the same time as Microsoft's network management software, while other vendor software might be completely compatible.

Flipping between the Microsoft Interface and an alternate interface

Speculation: This might be more common with Windows XP and Windows Server 2003, since Microsoft's preferred wireless interface came out during Windows XP's lifespan, and was widely getting deployed with Windows XP Service Pack 2. This means that vendor implementations were quite popular at the start of Windows XP's life, but then got used less over the following years. This guidance is not necessarily specific to only wireless connections; wired interfaces may also act similar.

This guide provides some details on how to start using Microsoft's code, rather than an interface that gets installed as part of a third party's driver installation package. Performing these steps might not improve things, and could even break a working setup. However, in more cases, these steps will fix something that is already broken. If things are working fine, then these are not recommended steps to perform. However, if things are not working fine, this may be a great option to attempt.

Switching between the interfaces may be doable with software. The best way to handle this might be to ask the third party software to disable itself. Check if that software has some sort of option/toggle which may be used to specify that Microsoft's network management should be getting used. For instance, Intel's custom software may have an option to disable Intel's custom software, and to rely instead on Microsoft's standardized software. Some documentation about some ways to perform this, which may or may not be helpful (depending on what driver software is already being used before work on the computer got started) include: NetGear guide (with pictures) to disabling some third party wireless card utilities, MS KB 968682: How to disable wirelss configuration services and enable XP WZC service, Linksys Article ID 21475, Linksys Article ID 4055: Connecting wirelessly with XP WZC, and guide to disabling Intel WiFi utility (with pictures). Note that those guides only mention some common examples. One reason there are so many guides is because this is a common practice that fixes more things than it breaks. Also note, though, that at least some guides are not necessarily accurate for (every version of) every piece of released software. Vendors may have produced multiple custom software packages, so the details required for one set of software (like a specific example of the “Intel PROSet/Wireless WiFi Connection Utility”) might not work with a different set of software (even if the software was released by the same company).

Use Microsoft's interface to establish Wi-Fi connections

In Windows Server 2003 and Windows XP with Service Pack 2 or Windows XP with Service Pack 3, one checkbox that may be handy is located in the properties of the wireless NIC. (So, go to the Network Connections screen. If the NIC is properly supported at all, the operating system is likely showing an icon for the NIC. (If not, re-install the NIC's drivers.) Choose an icon related to the NIC, and choose Properties.)

On the window that pops up (called something like “connectionName Properties”, e.g. “Wireless Network Connection 2 Properties”), Wi-Fi adapters should have a tab labelled “Wireless Networks”. On that tab, there may be a checkbox called “Use Windows to configure my wireless network settings”. (Picture: guide.) If that box is unchecked, know that checking that box has been known to fix wireless networking. Be sure to note whether that box is checked or unchecked, and any changes made, because this checkbox can frequently be a very important setting when trying to troubleshoot a wireless connection (although this is not always the cause of a solution that resolves the problems.)

If that checkbox doesn't magically resolve the issue, there is another approach that may enable Microsoft's “Wireless Zero Configuration” service (which has the abbreviated name of “WZCSVC”). Find that service in the list of operating system services. If that service exists, but is not running, then document the current configuration. Then, make sure that service' status is set to Started (by manually specifying to have the service be started). Also, document the old value and set the Startup-Mode to “Automatic” (not “Disabled”). Also, disable any services related to software provided by any third party vendor who created the NIC's hardware. (For example, if using a NIC carrying the Intel brand, see if there are any services related to Intel-branded networking software, like Intel Pro-Set.) This option is not necessarily recommended, as it might cause problems, or it might work. The specific details likely vary between the different pieces of software provided by different vendors.

On computers running older versions of Microsoft Windows (before Windows XP Service Pack 2), using the vendor's software was generally preferred. A key reason is that Microsoft's interface may have been widely insufficient, or even non-existent. This may be particularly true for wireless connections. Many people have preferred Microsoft's interface ever since Microsoft's “Wireless Zero Configuration” bundled with Windows XP SP2. Software develoeprs wishing to interact with this may be interested in MS KB 918997 (Microsoft Download Center: Wireless LAN API (KB918997). See also: Install Wireless Zero Configuration Service (which basically refers to network connection settings, install, service, disk, C:\Windows\Inf\NETWZC.INF).

OpenBSD wireless connectivity

The exact process can depend on details like what version of OpenBSD is being used. For instance, some older versions used a program called wpa_supplicant (e.g., see info).

However, things have been simplified in newer versions.

With newer versions, if all goes well, you should be able to see available Wi-Fi networks using:

sudo ifconfig nicdriver# scan

Actually, it will look something more like:

sudo ifconfig if0 scan


sudo ifconfig em0 scan

For details on getting the driver name, see: available NICs.

Choose the SSID by setting the nwid parameter. Also set the WPA key. Examples forthcoming

Some potential problems:

Firmware needed

man fw_update
fw_udpate -a -p .

The necessary files can be found from: Firmware for use with OpenBSD.

Insufficient power

Kernel message: urtwn0: timeout waiting for MAC auto ON

(urtwn0 was the name of the NIC)

Stefan Sperling's post says, “The driver believes that it is failing to power up the hardware.” To which, Heptas Torres's reply notes, “As it looks from outside the dongle is not powered up.” (Conversation also mirrored here: here.) Despite the discussion about timing (also noted FreeBSD forum post), here was the easy fix:

Unplugged USB Wi-Fi adapater from a USB hub that also had a keyboard which wasn't working quite right (Right shift acted like Ctrl), possibly due to the PS2-to-USB adapter involved with that keyboard. The USB hub used an extension cable to plug into a USB port on the back of a system.

Plug Wi-Fi adapater into a USB port at from of system.

Problem went away.

So, the idea of this being a power issue seems like a possibility that had a quite reasonably high likelihood.

Wireless connectivity in Linux

Some Linux distributions may support some Wi-Fi equipment, but with limitations like not automatically loading some “firmware” details, or even not including such firmware in a distribution.

Then, the software that a person can use may vary between distributions. For example, TechRepublic: 10 tools to connect to wireless networks in Linux. Ars Technica: Linux Kung Fu: Howto deal with Network Manager completely from the command line mentions “pre-NetworkManager” methods of configuring network devices.

Some of the more widely available tools may be:

  • Network Manager
  • iwlist (and similar, like iwconfig)
  • wpa_supplicant (has also been known to be used by BSD systems)

Sometimes, network adapaters might not show up in a ifconfig list. For instance, “ nmcli nm wifi off ” may have the effect of hiding the adapter from ifconfig's output (and have other effects, like making the device be inactive), while “ nmcli nm wifi off ” may undo that effect.

Here are details about some solutions. (At the moment, the option that is most fully detailed, here, is using the NetworkManager command line.)

iwlist scan | grep -i ESSID:
echo ${PAGER}
iwlist scan | ${PAGER}

An early experience: The second command shown has been known to show an error message by the Wi-Fi adapter, which was something like “device busy”, and not show the networks. However, retrying shortly (in a couple or few seconds) did show the networks just fine.


This has been used by various Linux-based operating systems, including Debian. It was created by Red Hat. There are multiple interfaces, and this can be used entirely from the command line. Wikipedia's article for NetworkManager identifies the project's home page as GNOME Wiki: Projects/NetworkManager.

Network Manager Command Line Guide

As a quick note, users who prefer to use something other than a graphical interface might appreciate the NetworkManager Text User Interface (nmtui). That may be pre-bundled with some distributions (e.g., Manjaro), but not others (e.g., Knoppix 7.2.0 CD). Presumably, systems that don't come with that interface may have a relatively easy way to add it.

However, the “command line” interface provides some benefits, such as easier scriptability and possibly being more widespread.

List network hardware

This command may list the networking hardware:

$ nmcli device list
DEVICE     TYPE              STATE        
eth0       802-3-ethernet    connected    
wlan0      802-11-wireless   unavailable  

That was an example of a system with one Ethernet NIC, and a Wi-Fi adapater.

The man page doesn't mention “nmcli d” as an option, although it has been shown to work. Instead, the man page lists “nmcli dev”, although another option is to use the full name which is “nmcli device”.

The word “ list” is the default, and doesn't need to be specified.

nmcli d show” has also been a documented variation. Testing indicated that this didn't work (show appeared to be an unrecognized option, in Knoppix 7.2.0), but maybe some other versions of the software use this.

Enabling Wi-Fi

Wi-Fi may need to be enabled. If you'd like, you can first check the status:
nmcli nm

The output is more than 80 characters long. e.g.:

$ nmcli nm
$ nmcli nm
running         connected       enabled         disabled   enabled         disabled  

(The output is not tab-separated. It is space-separated, and there are (probably?) spaces at the end of lines.)

The output of just one of those columns can be displayed, and changed, like this:

$ nmcli nm wifi
$ nmcli nm wifi on
$ nmcli nm wifi
$ nmcli nm wifi off
$ nmcli nm wifi on

If Wi-Fi is disabled, then the device won't even show up in ifconfig's output.

After enabling the Wi-Fi, the Wi-Fi adapater may automatically connect (using previously-saved settings), and get an IP address automatically assigned. (Getting that address may take a brief while, so if the network adapter is visible but there is no IP address assigned, success may be available simply by waiting a couple of seconds and then, again, checking for an assigned IP address.)

Scanning for a list of networks
echo ${PAGER}
nmcli d wifi list | ${PAGER}

The following was documented (but then not found to work). Maybe it works on some systems?

nmcli d wifi rescan

(Misc notes... might be relevant here...)

nmcli con list
Connecting to a network

To do this, first:

  • The Wi-Fi feature needs to be enabled. This may be worth checking (following the instructions that have just been provided).
  • Obviously, required details, such as the passphrase for the authentication security requirement, must be known.
nmcli d wifi connect SSID password PASSPHRASE

Customize the sections shown in capital letters:


This is commonly referred to as the name of the network.


If the passphrase contains a space, then make sure to place a space in the command line parameter. Doing that probably involves using quotation marks (or apostraphes) around the passphrase.

If specifying a numeric WEP key instead of a passphrase, add the phrase “wep-key-type key” (instead of relying on the default behavior, which is more like “wep-key-type phrase”).


Some of these details may be untested, and are simply based on some documentation.

To disconnect:

There are various ways. Any of these should work:

Disabling WiFi

Disable Wi-Fi (and then re-enable it later). The commands, described earlier, are repeated again here:

nmcli nm wifi off

(and then, later, after the Wi-Fi is desirable again...)

nmcli nm wifi on
Bringing the connection down (by ID)

First, get an ID or UUID

Second, either use:

nmcli con down id IDINFO

or use:

nmcli con down uuid UUIDINFO
Disconnect Wi-Fi device

Another option may be to disconnect the Wi-Fi device:

nmcli dev disconnect iface IFACENAME
Additional informational resources

The software's home page is titled “Linux WPA/WPA2/IEEE 802.1X Supplicant”, but then the first sentence starts out saying “wpa_supplicant is a WPA Supplicant for Linux, BSD, Mac OS X, and Windows with support for WPA and WPA2 (IEEE 802.11i / RSN).” So it is not Linux-only.

(Not much info is here at the current time.)

Wikipedia on wpa_supplicant

Wikipedia's article about Modular connectors: section about 8P8C says that despite common usage referring to Ethernet and CAT5 cables as RJ45, “it is incorrect to refer to a generic 8P8C connector as an RJ45. A telephone-system-standard RJ45S socket has a key which excludes insertion of an un-keyed 8P8C plug. The registered jack (RJ) standard specifies a different mechanical interface and wiring scheme for a RJ45S than TIA/EIA-568-B which is often used for modular connectors used in Ethernet and telephone applications.” (The Wikipedia article has some hyperlinked references omitted from the quoted text.) Wikipedia's article on “Registered jack”: section about RJ45 notes, “Virtually all electronic equipment which uses an 8P8C connector (or possibly any 8P connector at all) will document it as an "RJ45" connector.”

For further discussion on wired, see: network cabling.

[#netadrsn]: Network Addressing
Plans/Methods for addressing
Determining what addresses will be used when automatic addressing protocols hand out addresses and/or when manually assigned addresses are selected.
Automatic Addressing
Manual Addressing
Information about how to perform the manual address assignments in various platforms
[#seepubip]: Determining one's own public IP address

(Note: To perform a similar task, which is to locate a system's IP address (which may be from an address block used for “private” addresses, and generally is such a private address when working with IPv4 on non-firewalls), see getting a computer's current IP address.)

One way may be to send out network traffic that will generate a reply, and then to watch network traffic. However, that requires performing the action on a device that has a public IP address. This would also require parsing the information in the header of the IP packet.

Often a simpler method (much better for using when speaking on a telephone and just walking someone through the steps) is to visit a web site that reports the IP address. Although an IP packet's header may contain an address that gets translated by NAT, a device in between the web browser and the Internet may be less likely to translate the IP address shown in the web page's content. Examples may include: (which provides the answer, and also provides advertising), Smart-IP.Net (which appears to use Geo-IP and Google Maps), and others (e.g. see Google results for “ip detect”). Providing the functionality of showing a visitor's IP address is not difficult for a website that generates dynamic content, so quite a few sites may provide this sort of functionality in one way or another.

[#namtoady]: Name Resolution
Name resolution may be even more important than routing: It may be used for internal communications even if thre are no Internet connections that are actively up. A lot of software uses name resolution, including security software. If users cannot authenticate, that may limit their ability to do anything even if routing to the Internet does work.
[#routtraf]: Routing (firewalling)
Routing traffic
Basic routing
Traffic forwarding
Basic forwarding
[#tunltraf]: Tunneling Traffic
[#sshptfwd]: Creating a port forwarding rule using SSH
This is often a simple way to add encryption to traffic, even if the traffic is created (sent) or used (received) by software which does not support the method of encryption being used.
[#netldbal]: Load balancing of network traffic
[#drctsvrt]: Direct (Server) Return/Routing
Reducing the number of devices/processes that must handle return traffic.
IP troubleshooting

A guide to reduce struggles...

[#netdisvc]: (Network) Service discovery

Some services may be able to be configured rather automatically. Simply setting up service discovery may be a way to help those mutliple services be able to start working with minimal effort.

Implementations include:

Service Location Protocol
RFC 2165: Service Location Protocol (Version 2), RFC 3224: Vendor Extensions for Service Location Protocol Version 2
[#mdnssd]: Multicast DNS Service Discovery (“mDNS”/“DNS-SD”)
Used by Avahi, Apple (including Apple's Bonjour zero configuration networking software). Uses names of services such as those listed at's list of service types which says, “As soon as the correct IANA procedures are in place and formalized, the two lists will be re-unified and managed by IANA.” IANA's list of TCP and UDP port numbers shows IANA has reserved TCP and UDP port 5353 for Multicast DNS (and TCP and UDP port 5354 for Multicast DNS Responder IPC).
[#ssdp]: Simple Service Discovery Protocol
Internet Draft document about SSDP. It mentions a reservation for IPv4 multi-cast address citing address number five, which is documented by IANA at IANA's documentation of (IPv4) multicast addresses. However, that draft document indicates a port reservation has not yet occurred (in the last sentence of section 1, the “Changes Since 02” section), when in reality IANA's list of TCP and UDP port numbers has reserved 1900 TCP and UDP for SSDP. IANA's list of IPv6 multicase addresses section called “Variable Scope Multicast Addresses” notes FF0X::C for multiple values of X.
Zero configuration networking (“zeroconf”)

This may include implementations of Network Addressing and Name Resolution and (network) service discovery. Some implementations have been named zeroconf, including Zeroconf: IPv4 link-local addresses, Zeroconf (NetBSD-“Summer of Code”: a combination of the NetBSD project and Google's Summer of Code 2005)'s zeroconfd. More information about these technologies may be available at

Specific implementations

This information may be specific to certain implementation(s) of software that is related to networking.

Microsoft Windows Networking
[#wnnetcpl]: Microsoft Windows Control Panel Applet for Networking
Starting the Control Panel Applet from a command line

Like other control panel applets, this can be started from the command line. (See: running control panel icons) However, the precise control panel applet to use may vary.

MS KB Q192806: Control Panel tools accessible by command line mentions that “In Windows NT 4.0, Network properties is Ncpa.cpl”. This filename is also likely to be used with Windows XP and newer operationg systems, and Windows 2000. However, with Windows 95, 98 (and 98:2nd Ed), and ME, the filename is netcpl.cpl. It might be true that in some operating systems the filename may be netsetup.cpl.

To run the applet, pass the name of the applet to the Control Panel executable by using the syntax of:

control filename.cpl

Some other options (in case running control followed by the specified filename.cpl file doesn't seem to work) is to try running start control filename.cpl, or typing the *.cpl filename in the Run box, or running rundll. To describe that last option a bit further: from some text on MS KB Q192806: Control Panel tools accessible by command line, it appears that (for at least some operating systems) that may be basically equivilent to running:

rundll32.exe shell32.dll,Control_RunDLL filename.cpl

(However, even if for no other reason than really old 16-bit code, this is not likely to work on all operating systems: it seems likely that it was possible that the Control Panel which existed in Windows 3.1, uncommonly used as it was, may have supported the syntax of using the “control filename.cpl” syntax, while not supporting the syntax that requires a “rundll” type of program.)

On at least some systems, it may be possible to use the networking control panel applet to open the control panel applet for users, using “ control Ncpa.cpl users ” (as documented by Microsoft KB Q192806.

Using the graphical interface

The other way is to find the option in the control panel.

  • In Windows 95, this is a control panel icon called “Network”.
  • In Windows Vista, you'll need to “Veiw network status and tasks” in the “Network and Sharing Center”.
    • From the control panel, if “Classic View” is used, choose “Network and Sharing Center”.
    • If the default (“Control Panel Home”) view is used, either switch to “Classic View” in the left frame, or choose “View network status and tasks”. Or choose “Network and Internet”, and then either choose “View network status and tasks” or “Network and Sharing Center”.

    Once there, choose “Manage network connections” which should be visible in the left frame.