Specifications

Table Of Contents
VMware Server Virtual Machine Guide
198 VMware, Inc.
Considerations for Using NAT
Because!NAT!requires!that!every!packet!sent!and!received!from!virtual!machines!be!in!
the!NAT!network,!there!is!an!unavoidable!performance!penalty.!Our!testing!shows!that!
the!penalty!is!minor!for!dialup!and!DSL!connections,!and!performance!is!adequate!for!
most!VMware!Server!uses.
NAT!is!not!perfectly!transparent.!
It!does!not!normally!allow!connections!to!be!initiated!
from!outside!the!network,!although!you!can!set!up!server!connections!by!manually!
configuring!the!NAT!device.!The!practical!result!is!that!some!TCP!and!UDP!protocols!
that!require!a!connection!be!initiated!from!the!server!machine!!some!peer!to!peer
!
applications,!for!example!!do!not!work!automatically,!and!some! might!not!work!at!
all.
A!standard!NAT!configuration!provides!basiclevel!firewall!protection!because!the!
NAT!device!can!initiate!connections!from!the!private!NAT!network,!but!devices!on!the!
external!network!cannot!normally!initiate!connections!to!the!private!NAT!network.
Using NAT with NetLogon
When!using!NAT!networking!in!a!virtual!machine!with!a!Windows!guest!operating!
system!running!on!a!Windows!host,!you!can!use!NetLogon!to!log!on!to!a!Windows!
domain!from!the!virtual!machine.!You!can!then!access!file!shares!known!by!the!WINS!
server!in!the!domain.!
To!use!NetLogon,
!you!need!to!know!how!WINS!servers!and!Windows!domain!
controllers!work.!This!section!explains!how!to!set!up!the!virtual!machine!to!use!
NetLogon.!The!setup!process!is!similar!to!the!way!you!set!up!a!physical!computer!on!
one!LAN!that!is!using!a!domain!controller!on!another!
LAN.!
In!order!to!log!on!to!a!Windows!domain!outside!the!virtual!NAT!network,!the!virtual!
machine!needs!access!to!a!WINS!server!for!that!domain.!There!are!two!ways!you!can!
connect!the!virtual!machine!to!a!WINS!server.!You!can!connect!to!the!WINS!server!
provided!by!the
!DHCP!server!used!on!the!NAT!network,!provided!that!the!WINS!
server!is!already!set!up!on!the!host.!If!you!want!to!connect!from!the!virtual!machine!to!
a!WINS!server!not!set!up!on!the!host,!you!can!manually!enter!the!IP!address!of!the!
WINS!server.
Using NAT to Connect to an Existing WINS Server Already Set Up on the
Host
In!order!to!use!this!method,!a!WINS!server!in!the!same!workgroup!or!domain!must!be!
set!up!on!the!host.!These!steps!use!Windows!2000,!Windows!XP,!or