TweetFollow Us on Twitter

Demystifying Windows network browsing

Volume Number: 23 (2007)
Issue Number: 10
Column Tag: Windows on Mac

Demystifying Windows network browsing

A behind the scenes look at how it really works

By Joe Froehlich

Just browsing, thanks!

If you peruse the Windows Services Administration manual for Mac OS X Server, you'll find the following statement:

"Mac OS X Server can also provide network browsing service as a workgroup master browser or a Windows domain master browser for Windows clients. A workgroup master browser enables Windows computers to discover servers on one subnet. A domain master browser enables Windows computers to discover servers across subnets."

While this statement sounds simple enough, as with most things, there's more to the story. If you have Windows clients on your Mac OS X Server-based network, it's important to understand how Windows network browsing functions. In this article, we'll give you the grand tour.

The Language of Windows networking

Microsoft defines two distinct network entities: workgroups and domains. Let's start with a brief description of each so we're talking the same language.

A workgroup is a logical grouping of peer-to-peer computers that facilitates sharing resources (file and printers) among its members. While there's usually a one-to-one relationship between a workgroup and a subnet, in theory at least, a subnet can host multiple workgroups, and a given workgroup can span physical subnets.

A domain (not to be confused with an Internet domain) is a logical grouping of computers for administrative and security purposes. In a domain, all computers share a common directory database of resources and security information. A domain can reside on a single subnet, or it can span multiple subnets. A domain typically consists of a domain controller, member servers, and client workstations.

Browsing services in brief

On a native Windows network, the Computer Browser Service controls network browsing. On a Mac OS X Server-based network, this same service is implemented via Samba. Fundamentally, the browsing service on the respective platform is responsible for populating a client's view of the Windows network, as shown in Figure 1.


Figure 1: Browsing a Windows workgroup under Tiger and Vista

When you configure the Windows service on Mac OS X Server, your changes are reflected in the underlying /etc/smb.conf file. In Figure 2, for example, we've made our server a member of the Windows workgroup called EUROPA. In examining the [global] section of the smb.conf file, we see the following settings, which correspond to the Description, Computer Name, and Workgroup items on the General pane:

   server string = Mac OS X Server
   netbios name = osxsrv
   workgroup = EUROPA


Figure 2: The Windows service module in Mac OS X Server

How Windows network browsing works

When a Windows machine comes online, it broadcasts its presence--saying in effect, "Here I am and I have something to share with you". Other computers on the network are responsible for collecting the list of nodes that provide shared resources. When a client computer needs to access a shared resource, it consults the browse list (not the host directly sharing the resource) to locate the resource. Figure 3 provides an overview of this process.

The key point to remember is that, in addition to the machine providing the resource (the server) and the machine requesting the resource (the client), other machines, known as computer browsers, manage lists of available resources throughout the network.

Computer browser roles

There are several different roles a computer can assume in a Windows browsing environment. Depending on the installed operating system, a computer with the Computer Browser Service enabled can serve any of the following roles:

Master Browser. This machine collects and maintains the list of available network resources on its own subnet. The master browser fully replicates its information list with the domain master browser to obtain a complete browse list for the network, and then distributes it to backup browsers located on the same subnet.

Preferred Master Browser. This machine is a master browser that the administrator has configured manually (via a Windows registry setting) to be the favored master browser.

Domain Master Browser. This machine collects and maintains the master browse list of available resources for its domain. It also distributes and synchronizes the master browse list for master browsers on other subnets that have computers belonging to the same domain. This is the default role for a Primary Domain Controller (PDC).

Backup Browser. This machine receives a copy of the browse list from the master browser for its subnet, and then distributes it to other computers upon request. Clients that need to access a resource consult the backup browser not the master browser.

Potential Browser. This machine is capable of becoming a backup browser when and if its subnet's master browser instructs it to assume that role.

Non-browser. This machine is configured so it can't become a computer browser; as a result, it doesn't maintain a browse list. However, it can operate as a browse client, requesting browse lists from other computers operating as browsers on the same subnet.


Figure 3: Windows network browsing in action

Computer browser elections

In certain cases, computer browsers need to assume different roles. When this happens, potential browsers choose a new master browser, using a process known as an election. An election is initiated as a result any of the following events occurring:

A computer can't locate a master browser.

A preferred master browser comes online.

A Windows domain controller starts.

A backup browser can't contact a master browser to update its browse list.

The election process

Not surprisingly, a computer browser election is considerably friendlier than a political election. In short, all potential browsers present their qualifications during the election. Then, after several rounds of self-elimination (e.g. a browser disqualifies itself after encountering an opponent with higher qualifications), a single machine remains--the newly elected master browser.

Browser qualifications

There are several criteria for determining which computer browser is most qualified to win an election. In practice, the winner is usually determined by a combination of its operating system and its role on the network. In general, the more capable the operating system and the more important the machine's network role, the more likely it is to win an election. For example, an NT server running as a PDC beats a Windows 2000 Professional workstation. Likewise, all other criteria being equal, a preferred master browser beats a backup browser.

Election outcomes

The following rules determine, in the order listed, whether a browser wins an election:

If the election protocol version of the browser is greater than the election protocol version of its opponent, the browser wins. If not, the browser uses the next election criterion.

If the value of the election criteria (combined value of operating system and network role) for the browser is greater than that of its opponent, the browser wins. If not, the browser uses the next election criterion.

If the browser has been running longer than its opponent, the browser wins. If not, the browser uses the next election criterion.

If none of the above rules have determined the election, then the server with the lexically lowest name wins; e.g. a server named Alpha wins over a server named Beta.

Configuring browser roles on Mac OS X Server

While you use the Settings | General pane of the Windows service module to specify workgroup or domain membership, you use the Settings | Advanced pane, shown in Figure 4, to configure browser roles (Workgroup Master Browser and/or Domain Master Browser).

Master browser

You'll recall from our previous discussion that a master browser is responsible for collecting and maintaining browse lists on its own subnet. You must have a master browser on each subnet. This machine can be any Windows machine with the Computer Browser Service enabled, or a Mac OS X server running Samba and serving as a local master.

To configure a master browser, simply select the Workgroup Master Browser check box. In doing so, the [global] section of the smb.conf file reports the setting: local master = yes.


Figure 4: Browser role configuration

Domain master browser

The domain master browser is the master browser for the subnet in which it resides. Additionally, it propagates its browse list to the individual master browsers on each subnet in the domain. At the same time, the master browsers on each subnet distribute their browse lists to the parent domain master browser. If you have a Windows domain, regardless of whether it's on a single subnet or it spans multiple subnets, you need a domain master browser. This machine can be Windows server acting as a PDC, or a Mac OS X Server serving an equivalent role.

To configure a domain master browser, first set up Mac OS X Server as a WINS server, or register it with an existing WINS server for NetBIOS name resolution. Then, simply select the Domain Master Browser check box. In doing so, the [global] section of the smb.conf file reports the setting: domain master = yes.

Conclusion

Hopefully, this article has given you a better sense of how Windows network browsing works. If this article has elevated your interest in learning more about this subject, refer to the online documentation available on Samba's website at www.samba.org. In the meantime, Happy Browsing!


Joe is a seasoned technical writer and instructional designer with experience on both Windows and Mac platforms. He's a member of the Apple Consultants Network, the Microsoft Partner Program, and the IEEE Computer Society. You can reach him at froejoe@gmail.com.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

NTFS 14.3.318 - $19.95
This latest version supports the new macOS 10.12 Sierra! NTFS breaks down the barriers between Windows and OS X. Paragon NTFS effectively solves the communication problems between the Mac system and... Read more
iFFmpeg 6.2.2 - Convert multimedia files...
iFFmpeg is a comprehensive media tool to convert movie, audio and media files between formats. The FFmpeg command line instructions can be very hard to master/understand, so iFFmpeg does all the hard... Read more
ForeverSave 2.1.6 - Universal auto-save...
ForeverSave auto-saves all documents you're working on while simultaneously doing backup versioning in the background. Lost data can be quickly restored at any time. Define your preferred time... Read more
BetterTouchTool 1.961 - Customize Multi-...
BetterTouchTool adds many new, fully customizable gestures to the Magic Mouse, Multi-Touch MacBook trackpad, and Magic Trackpad. These gestures are customizable: Magic Mouse: Pinch in / out (zoom... Read more
EtreCheck 3.1.4 - For troubleshooting yo...
EtreCheck is an app that displays the important details of your system configuration and allow you to copy that information to the Clipboard. It is meant to be used with Apple Support Communities to... Read more
Together 3.7 - Store and organize all of...
Together helps you organize your Mac, giving you the ability to store, edit and preview your files in a single clean, uncluttered interface. Features Smart storage. With simple drag-and-drop... Read more
Together 3.7 - Store and organize all of...
Together helps you organize your Mac, giving you the ability to store, edit and preview your files in a single clean, uncluttered interface. Features Smart storage. With simple drag-and-drop... Read more
EtreCheck 3.1.4 - For troubleshooting yo...
EtreCheck is an app that displays the important details of your system configuration and allow you to copy that information to the Clipboard. It is meant to be used with Apple Support Communities to... Read more
Postbox 5.0.9 - Powerful and flexible em...
Postbox is a new email application that helps you organize your work life and get stuff done. It has all the elegance and simplicity of Apple Mail, but with more power and flexibility to manage even... Read more
DiskCatalogMaker 6.5.16 - Catalog your d...
DiskCatalogMaker is a simple disk management tool which catalogs disks. Simple, light-weight, and fast. Finder-like intuitive look and feel. Super-fast search algorithm. Can compress catalog data... Read more

Latest Forum Discussions

See All

Enneas Saga lets you lead your own demon...
Defend the land of Enneas Continent from the forces of evil in the new fantasy MMORPG from Lyto Mobi: Enneas Saga. Can’t wait? No problem. It’s available to download now on Android devices. | Read more »
Great zombie games in the spirit of Dead...
Dead Rising 4 arrives tomorrow, giving enthusiasts a fresh chance to take selfies with zombies and get up to other ridiculous end-of-the-world shenanigans. To really get into the spirit of things, we've gone and gathered the best zombie games that... | Read more »
Amateur Surgeon 4 Guide: Advanced tips a...
Amateur Surgeon 4 is still tackling the competition at the top of the App Store charts, so if you haven't tried it out yet, you should probably do that right away. If you've been at it for a while, though, perhaps you're ready to start expanding... | Read more »
Amateur Surgeon 4 Guide: Become the worl...
It's time to wield your trusty pizza cutter again, as Amateur Surgeon has returned with a whole fresh set of challenges (and some old, familiar ones, too). Starting anew isn't easy, especially when all you have at your disposal is a lighter, the... | Read more »
Le Parker: Sous Chef Extraordinaire (Ga...
Le Parker: Sous Chef Extraordinaire 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: | Read more »
Telltale Games really is working on a Gu...
Telltale Games' next episodic adventure is indeed Guardians of the Galaxy. A document tied to the voice actors strike suggested that the project was in the work, but now we have direct confirmation following an announcement at the Game Awards that... | Read more »
Amateur Surgeon returns to iOS and Andro...
Amateur Surgeon and its two sequels disappeared from the App Store some time and it was sad days for all. But now, just in time for the holidays, the Adult Swim favorite makes its joyous return in the shape of Amateur Surgeon 4, a remake with... | Read more »
The best board games on mobile
Sometimes you need to ditch all of the high speed, high action games in favor of something a little more traditional. If you don't feel like parting ways from your mobile device, though, there are still plenty of ways to get that old-school fix.... | Read more »
The best Facebook Messenger Instant Game...
Facebook's new Instant Games is now here, meaning you can play games with your friends directly via Facebook. It's a fun new way to connect with friends, of course, but it's also proving to be a solid gaming experience in its own right, with a... | Read more »
You can now play game's on Facebook...
Facebook launched its new Instant Games platform in an exciting new attempt to engage its user base. As a result, you can now play a number of different games directly through Facebook Messenger. All of these games run with HTML5, meaning you play... | Read more »

Price Scanner via MacPrices.net

New 2016 13-inch 2.0GHz MacBook Pros in stock...
Overstock.com has the non-Touch Bar 13″ MacBook Pros in stock today for $150 off MSRP. Shipping is free: - 13″ 2.0GHz MacBook Pro Space Gray (MLL42LL/A): $1349.99 $150 off MSRP - 13″ 2.0GHz MacBook... Read more
15-inch 2.6GHz Silver Touch Bar MacBook Pro o...
Adorama has the new 2016 15″ 2.6GHz Silver Touch Bar MacBook Pro (MLW72LL/A) in stock and available for $2349 including free shipping. Adorama charges sales tax in NY & NJ only. Their price is $... Read more
13-inch MacBook Airs on sale for up to $180 o...
Overstock.com has 13″ MacBook Airs on sale for up to $180 off MSRP including free shipping: - 13″ 1.6GHz/128GB MacBook Air (MMGF2LL/A): $869.99 $130 off MSRP - 13″ 1.6GHz/256GB MacBook Air (sku... Read more
13-inch 2.5GHz MacBook Pro (Apple refurbished...
Apple has Certified Refurbished 13″ 2.5GHz MacBook Pros (MD101LL/A) available for $829, or $270 off original MSRP. Apple’s one-year warranty is standard, and shipping is free: - 13″ 2.5GHz MacBook... Read more
Monday roundup of Holiday Mac sales: Up to $3...
Take up to $300 off MSRP on the price of a new Apple Mac at B&H Photo today as part of their Holiday sale. Shipping is free, and B&H charges NY sales tax only. Touch Bar MacBook Pros are in... Read more
12-inch WiFi Apple iPad Pros on sale for up t...
B&H Photo has 12″ WiFi Apple iPad Pros on sale for up to $50 off MSRP, each including free shipping. B&H charges sales tax in NY only: - 12″ Space Gray 32GB WiFi iPad Pro: $749 $50 off MSRP... Read more
9-inch Apple WiFi iPad Pros on sale for $20-$...
B&H Photo has 9.7″ Apple WiFi iPad Pros on sale for $20-$50 off MSRP, each including free shipping. B&H charges sales tax in NY only: - 9″ Space Gray 256GB WiFi iPad Pro: $779.95 $20 off MSRP... Read more
Holiday sale: Apple MacBook Airs available fo...
B&H Photo has 13″ MacBook Airs on sale for $100 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 13″ 1.6GHz/128GB MacBook Air (MMGF2LL/A): $899 $100 off MSRP - 13″ 1.6GHz/... Read more
13-inch Silver Touch Bar MacBook Pro in stock...
Amazon has the new 2016 13″ 2.9GHz/256GB Silver Touch Bar MacBook Pro (MLVP2LL/A) in stock today and on sale for $1749 including free shipping. That’s $50 off MSRP, and it’s the lowest price... Read more
Parallels Toolbox 1.3 for Mac Offers 25 Singl...
Parallels has launched Parallels Toolbox 1.3 for Mac, an upgrade that adds five new utilities to the stand-alone application which was released in August and is available exclusively online at http... Read more

Jobs Board

Lead *Apple* Solutions Consultant - Apple (...
# Lead Apple Solutions Consultant Job Number: 53586123 Pittsburgh, Pennsylvania, United States Posted: Nov. 28, 2016 Weekly Hours: 40.00 **Job Summary** The Lead ASC Read more
*Apple* Retail - Multiple Positions- Plano,...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Retail - Multiple Positions- Kansas...
Job Description:SalesSpecialist - Retail Customer Service and SalesTransform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Retail - Multiple Positions- Chicago...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
Hardware Design Validation Engineer - *Apple...
The Apple Watch team is looking for a Hardware Design Validation Engineer. This person will be part of the Apple Watch hardware team with responsibilities for Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.