troubleshooting wins & netbios name issues - urgent

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Jun 24th, 2008
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Hi all, over the last week we have had lots of issues with broadcasts on the network, I have done a scan, and there seems to be too many netbios/wins name resolution lookups, BUT, why is the pc sending it to the broadcast address of the network, not the name server?

please help asap

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Joseph W. Doherty Tue, 06/24/2008 - 03:37
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I'm not current on how the latest Windows clients deal with NetBIOS name resolution, but they had different modes of operations that determined whether they would resolve using a WINS name server and/or broadcast, and the sequence if using both.

Name Resolution Methods

Once a client establishes a session with a WINS server, the client can request name resolution services. The method used to resolve computer names to IP addresses depends on how the network is configured. Four name resolution methods are available:

• B-node (Broadcast node) B-node uses broadcast messages to resolve computer names to IP addresses. Computers that need to resolve a name broadcast a message to every host on the local network, requesting the IP address for a computer name.

B-node has two strengths. First, you don't need to configure a WINS server to use this method. Second, some non-WINS clients support b-node and-in conjunction with at least one WINS client (acting as a proxy)-can resolve computer names using this method. Also, b-node can be used with a local LMHOSTS file, which would enable name resolution on subnets.

B-node has two weaknesses. The method isn't routable and you can't use it to resolve names across routers. Broadcast messages can generate a lot of traffic on the network, especially as the number of computers on the network grows.

• P-node (Point-to-point node) P-node uses WINS servers to resolve computer names to IP addresses. As explained earlier, client sessions have three parts: name registration, name renewal, and name release. When a client needs to resolve a computer name to an IP address, the client sends a query message to the server and the server responds with an answer.

The main strength of p-node is that it's point-to-point and doesn't use a lot of network bandwidth. P-node is also routable, which enables clients to query servers across routers. However, any time the server is down or otherwise unavailable, name resolution fails.

• M-node (Modified node) M-node is a modified mode that combines b-node and p-node. With it, a WINS client first tries to use b-node for name resolution. If the attempt fails, the client then tries to use p-node. Because b-node is used first, this method has the same problems with network bandwidth usage as b-node.

• H-node (Hybrid node) H-node also combines b-node and p-node. With it, a WINS client first tries to use p-node for point-to-point name resolution. If the attempt fails, the client then tries to use broadcast messages with b-node. Because point-to-point is the primary method, h-node offers the best performance on most networks. H-node is also the default method for WINS name resolution.

NETBIOS and WINS do not use your standard DNS name servers for resolution. If this really is a problem you should configure a WINS server for your network and add the WINS option to your DHCP scope. It will take some time for this to become effective based on how long your current DHCP lease times are configured for.


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