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

iClock 4.2 - Customize your menubar cloc...
iClock is a menu-bar replacement for Apple's default clock but with 100x features. Have your Apple or Google calendar in the menubar. Have the day, date, and time in different fonts and colors in the... Read more
Parallels Desktop 13.3.0 - Run Windows a...
Parallels allows you to run Windows and Mac applications side by side. Choose your view to make Windows invisible while still using its applications, or keep the familiar Windows background and... Read more
Bookends 13.0.6 - Reference management a...
Bookends is a full-featured bibliography/reference and information-management system for students and professionals. Bookends uses the cloud to sync reference libraries on all the Macs you use.... Read more
macOS 10.13.3 Supplemental Update 1.0 -...
macOS High Sierra Supplemental Update includes security improvements to Safari and WebKit to mitigate the effects of Spectre. Version 1.0: Update fixes an issue where using certain character... Read more
Chromium 64.0.3282.167 - Fast and stable...
Chromium is an open-source browser project that aims to build a safer, faster, and more stable way for all Internet users to experience the web. Version 64.0.3282.167: [806388] High CVE-2018-6056:... Read more
Chromium 64.0.3282.167 - Fast and stable...
Chromium is an open-source browser project that aims to build a safer, faster, and more stable way for all Internet users to experience the web. Version 64.0.3282.167: [806388] High CVE-2018-6056:... Read more
Parallels Desktop 13.3.0 - Run Windows a...
Parallels allows you to run Windows and Mac applications side by side. Choose your view to make Windows invisible while still using its applications, or keep the familiar Windows background and... Read more
Bookends 13.0.6 - Reference management a...
Bookends is a full-featured bibliography/reference and information-management system for students and professionals. Bookends uses the cloud to sync reference libraries on all the Macs you use.... Read more
macOS 10.13.3 Supplemental Update 1.0 -...
macOS High Sierra Supplemental Update includes security improvements to Safari and WebKit to mitigate the effects of Spectre. Version 1.0: Update fixes an issue where using certain character... Read more
ffWorks 1.0.6 - Convert multimedia files...
ffWorks (was iFFmpeg), focused on simplicity, brings a fresh approach to the use of FFmpeg, allowing you to create ultra-high-quality movies without the need to write a single line of code on the... Read more

Latest Forum Discussions

See All

Alto's Odyssey (Games)
Alto's Odyssey 1.0.1 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0.1 (iTunes) Description: Just beyond the horizon sits a majestic desert, vast and unexplored. Join Alto and his friends and set off on an endless... | Read more »
Check out these 5 games that are a lot l...
So you're in love with Minecraft, but you're looking for something else to play as well? You've come to the right place then, because this list is all about games that are a bit like Minecraft. Some of them, more than others. [Read more] | Read more »
Our top 5 characters from casual RPG Cre...
Creature Quest definitely lives up to its name with a host of collectible creatures based on fantasy tales and world mythologies. To celebrate Creature Quest’s first birthday, we’re going to lay out what we think are the five best characters in the... | Read more »
Around the Empire: What have you missed...
Did you know that Steel Media has a whole swathe of other sites dedicated to all aspects of mobile gaming? Sure you'll get the very best iPhone news, reviews, and opinions right here at 148Apps, but we don't want you missing out on a single piece... | Read more »
All the best games on sale for iPhone an...
Oh hi there, and welcome to our round-up of the best games that are currently on sale for iPhone and iPad. You thought I didn't see you there, did you, skulking behind the bushes? Trust me though, the bushes aren't where the best deals are. The... | Read more »
The Battle of Polytopia Guide - How to H...
A new update just released for The Battle of Polytopia (formerly Super Tribes), which introduces online multiplayer. For all the fans of Midjiwan’s lite take on Civilization, this is certainly welcome news, but playing online isn’t as easy and... | Read more »
Here are the very best mobile games to p...
It's Valentine's Day! Did you get loads of cards and chocolates and other tacky, simple expressions of human affection? Did you send out tat because you find it almost impossible to express emotion unless there's a section dedicated to it at your... | Read more »
Florence (Games)
Florence 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: Florence is an interactive storybook from the award-winning lead designer of Monument Valley about the heart-racing highs and... | Read more »
Purrfect Date (Games)
Purrfect Date 1.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0 (iTunes) Description: Cats are a lil’ like marmite. Either you absolutely head-over-heels love’ em, or… nahhh, who are we kidding?! Everyone... | Read more »
More monsters to collect and evolve in C...
A laid-back mix of RPG and TCG, Creature Quest is all about building your deck, evolving your creatures and winning in battle. It’s the creation of VC Mobile, set up by Might and Magic producer Jon Van Caneghem. There are elements of that classic... | Read more »

Price Scanner via MacPrices.net

Lowest sale price available for 13″ 1.8GHz Ma...
Focus Camera has the 2017 13″ 1.8GHz/128GB Apple MacBook Air on sale today for $829 including free shipping. Their price is $170 off MSRP, and it’s the lowest price available for a current 13″... Read more
21-inch 2.3GHz iMac on sale for $999, $100 of...
B&H Photo has the 2017 21″ 2.3GHz iMac (MMQA2LL/A) in stock and on sale for $999 including free shipping plus NY & NJ tax only. Their price is $100 off MSRP. Read more
Apple refurbished Mac minis in stock again st...
Apple has restocked Certified Refurbished Mac minis starting at $419. Apple’s one-year warranty is included with each mini, and shipping is free: – 1.4GHz Mac mini: $419 $80 off MSRP – 2.6GHz Mac... Read more
Tuesday MacBook Deals: $250 off 15″ 2.9GHz Ma...
Adorama has the Silver 15″ 2.9GHz Apple MacBook Pro on sale today for $250 off MSRP. Shipping is free, and Adorama charges sales tax for residents in NY & NJ only: – 15″ 2.9GHz Silver MacBook Pro... Read more
Save up to $350 with these Apple Certified Re...
Apple has a full line of Certified Refurbished iMacs available for up to $350 off original MSRP. Apple’s one-year warranty is standard, and shipping is free. The following models are available: – 27... Read more
B&H offers $200 discount on Silver 15″ Ma...
B&H Photo has Silver 15″ Apple MacBook Pros on sale for $200 off MSRP. Shipping is free, and B&H charges sales tax for NY & NJ residents only: – 15″ 2.8GHz Touch Bar MacBook Pro Silver (... Read more
12″ Apple iPad Pro Sale of the Year! Models u...
B&H Photo has 12″ #iPad Pros on sale for up to $150 off MSRP. Shipping is free, and B&H charges sales tax in NY & NJ only: – 12″ 64GB WiFi iPad Pro: $719 $80 off MSRP – 12″ 256GB WiFi... Read more
Deals on 32GB 9″ iPads: Up to $50 off MSRP, s...
B&H Photo has 2017 9.7″ 32GB iPads on sale for $299 including free shipping plus NY & NJ sales tax only. Their price is $30 off MSRP, and it’s currently the lowest price available for these... Read more
15″ 2.2GHz Retina MacBook Pro available for o...
Apple has Certified Refurbished 15″ 2.2GHz Retina MacBook Pros available for $1699. That’s $300 off MSRP for this model, and it’s the lowest price available for a 15″ MacBook Pro currently offered by... Read more
13″ 3.1GHz/256GB Silver Touch Bar MacBook Pro...
Amazon has the Silver 13″ 3.1GHz/256GB Touch Bar MacBook Pro (MPXX2LL/A) on sale for $1649.99 including free shipping. Their price is $150 off MSRP, and it’s the lowest price available for a new 13″... Read more

Jobs Board

*Apple* Retail - Multiple Positions - Apple,...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
Strategist, *Apple* Media Products, Content...
# Strategist, Apple Media Products, Content and Marketing Job Number: 113399632 Santa Clara Valley, California, United States Posted: 20-Feb-2018 Weekly Hours: 40.00 Read more
*Apple* Store Leader - Retail District Manag...
Job Description:Job SummaryAs more and more people discover Apple , they visit our retail stores seeking ways to incorporate our products into their lives. It's your Read more
*Apple* Retail - Multiple Positions - Apple,...
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 - Apple,...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.