Subject: WINS -- Windows Internet Naming Service
Author: dns
In response to: The Second Layer Abstraction -- NetBIOS Name And Domain Name
Posted on: 07/07/2006 08:29:17 PM
WINS is short for Windows Internet Naming Service, a system that determines the IP address associated with a particular network computer assigned with a NetBIOS name, which is a 16-byte address that is used to identify a NetBIOS resource on the local area network (LAN). This is called NetBIOS name resolution. WINS supports network client and server computers running Windows and can provide name resolution for other computers with special arrangements. Determining the IP address for a computer is a complex process when DHCP servers assign IP addresses dynamically. For example, it is possible for DHCP to assign a different IP address to a client each time the machine logs on to the network.
WINS uses a distributed database that is automatically updated with the names of computers currently available and the IP address assigned to each one.
WINS server is called via NetBIOS Name Service (NBNS) if match is not found in local cache.
Here is an example as to how a computer NetBIOS name is resolved. The traffic details of ping are listed below:
c:\ ping HostNo2
---------------------
-> 192.168.0.1 192.168.0.255 NBNS* Name query NB HostNo2<00>
192.168.0.2 Broadcast ARP Who has 192.168.0.1? Tell 192.168.0.2
-> 192.168.0.1 192.168.0.2 ARP 192.168.0.1 is at 00:01:02:4f:5b:6e
<- 192.168.0.1 192.168.0.2 NBNS Name query response NB 192.168.0.2
-> 192.168.0.1 192.168.0.2 ICMP Echo request
<- 192.168.0.1 192.168.0.2 ICMP Echo reply
* NBNS -- NetBIOS Name Service, using port 137
>
> On 07/06/2006 09:25:39 PM
dns wrote:
The logic IP address is usually further encapsulated by a NetBIOS name or domain name, for the purpose of:
readability -- an abstract name based networks is more readable and memorized.
portability -- an abstract name based application can run on any machine with different IP address.
scaleability -- an abstract name based network architecture can hook more than one computers (IPs) to serve a single well-known domain name by diversifying the network traffic.
For example, few people know what '66.94.230.41' is because it is hard for human beings to memorize such a long meaningless digits. But most people know what 'www.yahoo.com' is.
In terms of portability, the domain 'www.yahoo.com' can run on any IP address like '66.94.230.41' or '66.94.234.13'
For scaleability, 'www.yahoo.com' can hook a cluster of machines running on different geographical locations to tackle local traffic for fast turn out.
References:
