Browser Issue on Microsoft Networks

Windows Tips & Secrets
1998 PLATINUM technology, Inc.

Reprinted with permission from Platinum Technology, Inc.

Have you ever wondered why that flashlight comes on every time you click Network Neighborhood? Or why some computer names aren't on the list or haven't dropped off? Resource browsing problems plague everybody. The problem relates to how computers communicate and broadcast their services in Microsoft networks: Windows for Workgroups, Windows 95, and NT clients accessing any number of server platformsNT Server, NetWare, etc. Browsing headaches increase with more clients, protocols and segments. We'll try to clarify how browsing behaves and offer a few suggestions to streamline the process.

Who's Got the List?

You are browsing resources when you look for a share to map to, open network neighborhood, or use Net View from the command prompt. The only way to know what is available is to check a list. A Browse Master maintains the list. Most of the problems associated with browsing can be traced to the power struggle for control of the browse list.

Remember school trips. You loaded a bus at 3:00 am with a couple of chaperones, drove all morning to get to Disneyland, went on every ride twice, ate too much, and drove all night to get back home? Well, imagine Microsoft sponsored that trip.

You board the bus, check in, and take your seat. You remember your friend, Stacy, had said she would let you borrow her Discman, but you have no idea where she is . You shout, "Who's got the list." A teacher up front sucking down coffee is too busy with roll call to talk to you, so she hands you a list of her backups. You pick out a name at random and call it out. He answers from the row behind you. You ask him for the list and he gives you a copy. You find Stacey's name and seat assignment, walk over to her, and ask to borrow her Discman. Of course, she's already using it, but says maybe you can borrow it later. Sulking, you return to your seat.

You are the Client computer. The chaperone is the Master Browser (MB). The MB keeps a list of all servers and their shared resources. Any NT server or any Windows client running File and Print Sharing for Networks is considered a server and will be tracked on the browse list. In the situation described above, Stacey's computer has File and Printer Sharing running (you can see her on the list), but her CD-ROM drive is not currently shared.

Tip #1

The fist step in reducing browser errors is to install File and Printer Sharing for Microsoft Networks for every Windows 95 and 3.x machine that you want to share resources. Remove this service from any computer not sharing resources. It will free memory on the computer and reduce the size of the browse list.

Tag, You're It by Popular Vote

You get on the bus and no one else is there. You start making a list as people get on board. You grab somebody and make them hand out copies of the list so that everyone knows who's got the best music, snacks, or magazines and will share.

Master Browsers are elected. The first computer on the network that is capable wins the election and becomes the MB. The Master Browser tells potential browsers whether they will maintain a browse list (become Backup Browsers). The second computer on the network will become a Backup. Then, for every 32 computers, one new Backup Browser will be selected up to a maximum of three. It works that way for all Microsoft networks. By default, all clients can be elected Browse Masters and they can all call for a Master Browser election if they can't find one on the network.

Each computer that participates in an election is weighted by several factors. Elections are handled by passing messages to each server's mail slot. As you can imagine, calling and deciding elections involves a large amount of network chatter. You can streamline the process by deciding in advance how each computer will participate in elections.

Tip #2

The parameter that determines how a computer participates in browsing is called "MaintainServerList=". All Microsoft clients and servers use this parameter, but it is changed differently in each. Browser status can be set to Auto (is a potential browser), Enabled (is always a potential browser), or Disabled (is never a browser). When a computer joins the network, if its switch is set to Enable or Auto, it will contact the MB and be told whether to become a BB. If they don't hear a response from the MB, they will call an election and could become the MB themselves. If the switch is set to Disabled, they will never become browsers. For each client, here's how to modify MaintainServerList :

• Windows 95Right-click [Network Neighborhood]PropertiesConfiguration. Select File and Print Sharing for Microsoft Networks. Click PropertiesAdvanced. Under Property select Browse Master. Under Value select Auto, Enabled, or Disabled. Click Ok. Click OK again.

• Windows 3.xEdit the SYSTEM.INI file and add MaintainServerList=No, Yes, or Auto under label [Network].

• Windows NTOpen the registry key HKLM\System\CurrentControlSet\Services\Browser\Parameters. Set value to Auto, Yes, or No.

Plan out which computers you want to be browsers and weight the election on each machine. Where machines are always being turned on and off they should remain set to Auto. The computers you want for browsers are the ones you never turn off and/or the computers with the most RAM and processor speed Enable that best three or four first. If there are any NT Workstations or servers in the workgroup they should be enabled. If you have three NT servers in a workgroup or domain, no other machine will ever win the election. In that case, disable browser participation on all the other computers in that network to prevent unnecessary network traffic. Disable Windows 3.x clients if there is anything better on the network, they are the most unstable browsers.

Maintaining an Accurate List

The Master Browser gives copies of the Browse list to Backup Browsers who request a new list every 15 minutes. Servers (computers with resources to share) give their names to the MB. Sometimes either the server or MB becomes so busy that it does not check its mail slot in time and misses an announcement. If the MB does not hear from a server for three 12-minute periods then the MB drops them from the browser list. That means that your bus could be on the road for 51 minutes before anybody is reported missing (three 12-minute periods and 15 minutes for the BB to request a new list). It works both ways, if an MB doesn't respond three times in a row to a client's request, the client calls for an election.

Back on the Bus

The teacher arrives. She takes one look at you and says, "Take a seat, kid." She says, "Let's have an election." Without even waiting for an answer she shouts, "I win. Call out your names!" She makes her list and hands you a copy. "Back me up, kid." You start handing out copies of the list while the others snicker. The teacher is the Domain Master Browser (DMB). You've just joined a domain called BusTrip and she's your Primary Domain Controller (PDC). The PDC is so heavily favored in the election that it will not lose.

Tip #3

Join a Domain. The centralized administration that NT server domains offer will streamline browsing . On Windows for Workgroups and Windows 95 machines in the domain be sure to set the Workgroup name to be the same as the domain name [Control Panel][Network]. This ensures that all the computer names show up on the domain browse list.

Going Wide

You're caught up with your homework, so Mom lets you go on the International Club trip. You get on the bus and it's total bedlam. The riders are speaking languages (protocols) you don't even recognize. Many kids are obviously better qualified than you, but you're elected as Backup Browser anyway, because you're the most qualified English-speaker. The MB chooses a Backup Browser for each protocol, and separate Master Browsers may maintain these lists.

Tip #4

Use the fewest number of protocols that you can to reduce browser overhead.

The teacher (PDC) is still up front handing out lists, but every fifteen minutes she's on the radio to other busses (segments) and reading her list to the master browser on that bus. They're reciting the lists back and forth over the radio and that's taking a lot of time. It's also harder now for clients in different subnets to locate the DMB. The WINS service allows WAN-wide browsing by providing this information dynamically. In our model WINS would be a radio dispatcher listening to the radio broadcast requests of the teachers on each bus and responding with the number of the bus they need. This is extremely helpful when you go from a segmented domain to a multiple domain model.

Tip #5

Use TCP/IP with WINS on segmented domains in order to see resources in other subnets or domains.

The International Club Trip of Your School is one convoy of many going to the International Club Expo. Thousands of other convoys are on the same highway and talking to each other on the same radio frequency. Every 15 minutes the teacher on your bus announces her name to the other bus trips on the road. Depending on how she trusts the other teachers or how they trust her, they will exchange lists of students. If she hasn't heard from one bus in forty-five minutes (3 announcements), then she assumes that convoy has crashed and she removes their names from her list. Suddenly, you remember that Stacy transferred to another school, but she still has a Discman you would like to borrow. "She owes me one, " you think, and you call out for a list. You get your English copy of the list from the Backup Browser and find out which Bus and School Stacy is riding. You get on the radio and make your request but she never responds. Later you found out that her bus pulled off the road with a flat tire 96 minutes before you got your copy of the Browse List. Sulking, you return to your seat and spend the rest of the trip staring out the window.

Tip #6

When your network has NT workstations or servers, there is one more setting you can change to weight the MB election process. You can force a machine to try to be the DMB by setting the IsDomainMasterBrowser switch. A DMB forces an election every time it starts. It rarely loses. Use this in workgroups when you want one machine to be dedicated as the MB exclusively. In a domain, the PDC will be the DMB, but you can set this switch to make a machine a dedicated Backup Browser. In a WAN, each segment will elect it's own MB; use this switch to make at least one NT box in each segment the MB.

• Open the registry key HKLM\System\CurrentControlSet\Services\Browser\Parameters and change IsDomainMasterBrowser's value to Yes.

Still, despite the added complications, we are discussing a stable, ideal model of Microsoft Network browsing. In the real world computers that are Master Browsers are being turned off. New elections are being called. Some computers don't get information in time and assume that they are Master Browsers when they are not. Less appropriate computers win elections occasionally, and some fight constantly to be Master Browsers when they should just quit. Most of the problems can be pared away, but large, complicated domain configurations will always experience browse lag time.

Last Tip

The best method to rule out browser problems is to use the command line utility NET VIEW. This command calls for a copy of the Browse list only from the MB. It will be the most updated list online.

For More Information

For more information, go to the Platinum Technology, Inc. web site at:
https://www.platinumtechnology.com.

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