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

Parallels Desktop 13.2.0 - 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
jAlbum Pro 15.0 - Organize your digital...
jAlbum Pro has all the features you love in jAlbum, but comes with a commercial license. You can create gorgeous custom photo galleries for the Web without writing a line of code! Beginner-friendly... Read more
iFinance 4.3.4 - Comprehensively manage...
iFinance allows you to keep track of your income and spending -- from your lunchbreak coffee to your new car -- in the most convenient and fastest way. Clearly arranged transaction lists of all your... Read more
VueScan 9.5.92 - Scanner software with a...
VueScan is a scanning program that works with most high-quality flatbed and film scanners to produce scans that have excellent color fidelity and color balance. VueScan is easy to use, and has... Read more
Scrivener 3.0 - Project management and w...
Scrivener is a project management and writing tool for writers of all kinds that stays with you from that first unformed idea all the way through to the first - or even final - draft. Outline and... Read more
SuperDuper! 3.0.1 - Advanced disk clonin...
SuperDuper! is an advanced, yet easy to use disk copying program. It can, of course, make a straight copy, or "clone" -- useful when you want to move all your data from one machine to another, or do... Read more
jAlbum 15.0 - Create custom photo galler...
With jAlbum, you can create gorgeous custom photo galleries for the Web without writing a line of code! Beginner-friendly, with pro results - Simply drag and drop photos into groups, choose a design... Read more
Scrivener 3.0 - Project management and w...
Scrivener is a project management and writing tool for writers of all kinds that stays with you from that first unformed idea all the way through to the first - or even final - draft. Outline and... Read more
SuperDuper! 3.0.1 - Advanced disk clonin...
SuperDuper! is an advanced, yet easy to use disk copying program. It can, of course, make a straight copy, or "clone" -- useful when you want to move all your data from one machine to another, or do... Read more
Parallels Desktop 13.2.0 - 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

Latest Forum Discussions

See All

The mobile gamer's guide to Black F...
We're starting to catch wind of some exciting deals in the mobile gaming space for Black Friday. There are big discounts on mobile phones and accessories cropping up already, so you might want to get a move on things ahead of the big day. It's... | Read more »
The best pre-Black Friday deals - Novemb...
Black Friday will soon be upon us, but online retailers are already getting a headstart on the steep discounts. Don't wait until Friday—you'll find some pretty good deals all over the internet without waiting in lines or competing with other... | Read more »
Mighty Battles guide - how to build a so...
Mighty Battles, the latest title from Hothead Games, is set to take the App Store by storm. The game puts a welcome twist on lane battlers, adding FPS elements to spice things up a bit. You'll collect cards to put your own military unit to gether,... | Read more »
Rules of Survival guide - how to be the...
The PUBG craze makes its way to mobile, with more and more battle royale games debuting on iOS and Android. Rules of Survival joins the ranks of mobile PUBG-likes, offering a classic battle royale experiences that doesn't vary too much from its... | Read more »
The best new games we played this week -...
The weekend is upon us friends, and it's time to take a look back and reflect on all of the wonderful games we've played over the past few days. This week was jam packed with new releases. There were some big, long awaited launches, some fun... | Read more »
Lineage II: Revolution guide - tips and...
At long last, Lineage II: Revolution has now come to western shores, bring Netmarble's sweeping MMORPG to mobile devices. It's an addictive, epic experience, but some of the systems in the game can be a bit overwhelming. Here are a few tips to help... | Read more »
A Boy and His Blob (Games)
A Boy and His Blob 1.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0 (iTunes) Description: | Read more »
Fight terrible monsters and collect epic...
Released on Western markets early last month, Dragon Project, created by Japanese developer COLOPL, brings epic monster hunting action to mobile for the very first time. Collect a huge array of weapons and armor, and join up with friends to fight... | Read more »
I Am The Hero (Games)
I Am The Hero 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: I Am The Hero is a pixel art, beat 'em up, fighting game that tells the story of a "Hero" with a glorious but mysterious past.... | Read more »
Kauldron (Music)
Kauldron 1.0 Device: iOS Universal Category: Music Price: $3.99, Version: 1.0 (iTunes) Description: Kauldron is our warmest sounding, punchiest synth yet! A completely new modeling technology, combined with carefully designed... | Read more »

Price Scanner via MacPrices.net

Save up to $180 with Apple Certified Refurbis...
Apple has Certified Refurbished 2017 13″ MacBook Airs available starting at $849. An Apple one-year warranty is included with each MacBook, and shipping is free: – 13″ 1.8GHz/8GB/128GB MacBook Air (... Read more
Black Friday deals on Apple Macs now live at...
Amazon has MacBook Pros, MacBook Airs, MacBooks, and iMacs on sale for up to $200 off MSRP for Black Friday week. Shipping is free. Note that stock of some Macs may come and go during the week, so... Read more
Black Friday pricing on Macs and iPads now av...
B&H Photo has lowered prices on many Macs, iPads, and iPad Pros as part of their Black Friday week sale. Save up to $200 on MacBooks and iMacs and up to $150 on iPads. B&H charges sales tax... Read more
Best Apple iPad deals this weekend, up to $80...
Apple resellers are offering 9.7″ iPads and 10.5″ iPad Pros for up to $80 off MSRP this weekend as part of their early Holiday and Black Friday sales: Adorama is offering new 2017 9.7″ 32GB WiFi... Read more
Early Black Friday sale: Apple iMacs for up t...
B&H Photo has 27-inch iMacs in stock and on sale for up $130-$150 off MSRP including free shipping. B&H charges sales tax in NY & NJ only: – 27″ 3.8GHz iMac (MNED2LL/A): $2149 $150 off... Read more
Apple restocks refurbished Mac minis starting...
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
Save on 12″ MacBooks, Apple refurbished model...
Apple has Certified Refurbished 2017 12″ Retina MacBooks available for $200-$240 off the cost of new models. Apple will include a standard one-year warranty with each MacBook, and shipping is free.... Read more
Early Holiday sale: 12″ iPad Pros for up to $...
B&H Photo has 12″ iPad Pros on sale today for up to $130 off MSRP. Shipping is free, and B&H collects no sales tax outside NY & NJ: – 12″ 64GB WiFi iPad Pro: $749, save $50 – 12″ 256GB... Read more
Holiday sale prices on Apple 13″ MacBook Pros...
B&H Photo has 2017 13″ MacBook Pros in stock today and on sale for $100-$150 off MSRP, each including free shipping plus NY & NJ sales tax only: – 13-inch 2.3GHz/128GB Space Gray MacBook Pro... Read more
Sale: 13″ MacBook Airs starting at $899, $100...
B&H Photo has 2017 13″ MacBook Airs on sale today for $100 off MSRP including free shipping. B&H charges NY & NJ sales tax only: – 13″ 1.8GHz/128GB MacBook Air (MQD32LL/A): $899, $100 off... 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
Product Manager - *Apple* Pay on the *Appl...
Job Summary Apple is looking for a talented product manager to drive the expansion of Apple Pay on the Apple Online Store. This position includes a unique Read more
*Apple* Pro/Consumer Apps Support Engineer -...
…exemplify AppleCare's expert technical support paired with exceptional customer service for Apple 's software apps. This person is a problem solver, who understands Read more
Partner Marketing Manager, *Apple* Pay - Ap...
Job Summary The Apple Pay partner marketing team is looking for a Marketing Manager to develop and drive US programs. The right candidate will be passionate about Read more
*Apple* Solution Consultant - Apple (United...
# Apple Solution Consultant - Rochester, MN Job Number: 113037950 Rochester, MN, Minnesota, United States Posted: 19-Sep-2017 Weekly Hours: 40.00 **Job Summary** Are Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.