RedAsh's Blog

REFRESH alot from Spring Singapore for the past few weeks, RAS (they call it "Big Bouncer" in SCS), WINS (Windows Internet Name Service - to referencing NetBIOS name). = a central mapping of host names to network addresses, alike what DNS is to domain names!

The key difference between WINS and DNS? The former is for LAN the later is for Internet.

One thing interesting here is that WINS is quite involved with DHCP. Unlike DNS the mappings are dynamically updated (e.g. at workstation boot), so that when a client needs to contact another computer on the network it can get its up-to-date IP address which may be issued by a DHCP server, aside from this the WINS functionality provides a way of keeping the client names unique on the network.

Networks normally have more than one WINS server and each WINS server should be in push/pull replication; where more than two WINS servers are required the best practice replication model is the hub and spoke, thus the WINS design is not central but distributed. Each WINS server holds a full copy of every other related WINS system's records. There is no hierarchy in WINS (unlike DNS), but like DNS its database can be queried for the address to contact rather than broadcasting a request for which address to contact (ICMP - ping). The system therefore reduces broadcast traffic on the network, however replication traffic can add to WAN/LAN traffic, although this can be set to replicate in non busy periods. By design any WINS client can register any name with any WINS server. This makes the system prone to abuse or unreliable through poor administration.

All WINS clients should be configured to use a primary WINS server and a different secondary WINS server. The secondary would normally be the hub server, The setting of which WINS servers to use is either in the DHCP scope options or a per client hard coded value. ~ this is also the reason why I see 3 IP for the DNS resolution... 2 of them are LAN for WINS, one is the primary(the spoke), the other is the secondary (Hub to DNS)

As of Windows 2000, DNS provides the favored alternative to WINS, as part of Active Directory.[1]

In theory, if DNS is available, WINS is only necessary if pre-Windows 2000 clients or servers need to resolve names. In reality, especially in large enterprise environments, applications such as SMS 2003 with its use of the 1A record, SQL Server 2000 for use of named pipes and Exchange Server 2000 and 2003 often still require WINS for full functionality.

The WINS service from Microsoft is only available as a service to run on the Windows Server family of operating systems. The WINS client from Microsoft is common across all its operating systems including DOS. ( note that WINS clients can be devices such as IP phones, and printers.)