Broadcast

Select Certification Bootcamp :
MCSE MCSE+Security CCNA CCNP RHCE Register Course Fees Home

Leading MCSE, CCNA, CCNP Certification boot camp training provider in India, USA, UK.

Broadcast

If the name cannot be found in the NetBIOS Name Cache, the system attempts to find the name using a broadcast on the local network. A broadcast is a necessary evil. It takes up bandwidth, but in many cases is the simplest way to find a system.

NetBIOS uses UDP (port 137) to send a Name Query to every computer on the local network. Every computer must then take the packet and pass it all the way up the protocol stack to NetBIOS so the name can be checked against the local name table. Two problems with using a broadcast are increased network traffic, and wasted CPU time on all the systems as the request is passed to NetBIOS to check names that don’t exist.

You are going to see two methods that enable you to resolve names without broadcast traffic. You should note that broadcasts are a throwback to the early days of networks when computers were slower, networks tended to be single segments, and the bandwidth of networks was more than enough to cover the occasional broadcast.

You can use a couple of registry entries to customize the broadcast function. These are under the following registry key:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NetBT\Parameters

The entries are as follows:

BcastNameQueryCount. The number of times the system retries the broadcast for the name. The default is three times.
BcastQueryTimeout. The amount of time to wait before retrying the Name Query broadcast. The default is 7.5 seconds.

Vibrant Advantage :

No Prestudy
Longest Duration Camp
Chalk Talk Training
Highest Passing Rate
Bootcamp since 1999
Guaranteed Certification ...

Testimonials :

MCSE Certification boot camp

The instructor taught real world experience and did not just teach us to pass the test. He knew the subject well and was encouraging. His lectures were very well delivered....

Colver Dennis, USA