Microsoft Confidential Windows 2000 活动目录设计 与部署: 最佳实践 微软产品技术顾问 微软中国有限公司 Microsoft Confidential Agenda  Active Directory™ Strategy And Roadmap  Active Directory Design: Best Practice Active Directory Deployment: Best Practices 

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Transcript Microsoft Confidential Windows 2000 活动目录设计 与部署: 最佳实践 微软产品技术顾问 微软中国有限公司 Microsoft Confidential Agenda  Active Directory™ Strategy And Roadmap  Active Directory Design: Best Practice Active Directory Deployment: Best Practices 

Microsoft Confidential
Windows 2000 活动目录设计
与部署: 最佳实践
微软产品技术顾问
微软中国有限公司
Microsoft Confidential
Agenda

Active Directory™ Strategy And
Roadmap

Active Directory Design: Best Practice
Active Directory Deployment: Best
Practices

Microsoft Confidential
Today’s Directory Roles

Application-specific


E-Mail address book/White pages


Information ‘joined’ from multiple
directories
NOS directory


Name and e-mail address information
Enterprise directory


Coupled tightly to an application
Typically a
database
Users, computers, devices,
applications,…
Outward-facing directory

Users and profiles
Typically
an LDAP
directory
Microsoft Confidential
Before Active Directory…

For each Windows NT® 4.0 domain:





Domain Controllers (PDC, BDC)
The Computer Browser
WINS (in many domains)
Exchange directory (in many domains)
Each system



Has unique object, admin, monitoring,
backup/restore, and security models
Maintains replicated objects
May have scalability issues
Microsoft Confidential
The NOS Directory
Motivation

Store of objects, used by variety of
applications, distributed where needed
on the network


Example: Single Sign-On
The idea isn’t new

Banyan Vines DS (1984)


Directory service for PC email and security
Novell NDS (1993)

Netware 4.0 introduced NDS to overcome
limitations of Netware 3.x "bindery"
Microsoft Confidential
Design Choices

LDAP access and data model




DNS-based object naming and server discovery



Enables globally unique namespace
Based on de-facto Internet locator service
Security



Protocol was becoming industry standard
Object hierarchy permits subtree-scoped queries
Schema defines attributes and object classes
Multiple authentication paths (NTLM, Kerberos, other),
one authorization model
Attribute-level access control - required for data
sharing between applications
In-place or side-by-side upgrade

Learned from Novell: offer upgrade flexibility!
Microsoft Confidential
Replication Design Choices

Multi-master




Attribute-level granularity



When attribute changes, replicate entire new value
Reduces network traffic and lost updates versus
object-level granularity
State-based




Needed for local password update
Approximately “last writer wins”
Eventual convergence
Send current state not a log
Predictable storage overhead, needed anyway for full sync
Tombstones for deletes
Transitive (“store and forward”)



Communicate update to somebody not everybody
Big win with mixed link speed - once per slow link
Automated topology generation (“KCC”)
®
Microsoft Confidential
Windows 2000 and Active
Directory

Kerberos and NTLM authentication service


Public Key Infrastructure


Store information about applying policies
DFS and FRS


Printer information is published in AD
Group Policy


Locate certificates & perform service location
Print service location


Store user and password information
Store configuration data
DNS, DHCP, IPSec, IAS (RADIUS), QoS

Store configuration data (i.e. RAS policy)
Microsoft Confidential
®
Case Study: Microsoft ITG
13 Master User Domains (MUDS)
2-Way Trusts
Africa
Central
Europe
Far
East
1-Way Trusts
Middle
East
MSLI
Corp
MSForest
North Northern South Southern
MSNBCI Redmond America Europe America
Europe
SYSWINNT
AppsWGA
Resource Domains (approx 420)

Windows NT 4.0 Domain Model

Approximately 5000 trusts (!)
South
Pacific
VMUDVendor
Microsoft Confidential
Case Study: Microsoft ITG
Norway
Finland
Poland Russia
DenmarkSweden
Ireland
Holland Czech Rep
Germany
England Belgium
Austria
France Switzerland
Spain
Hungary
Italy
Portugal
Turkey
Greece Israel
Morocco
Data
Center
Korea Japan
China
Taiwan
Hong
New Delhi
KongPhilippines
Bombay
Thailand
Bangalore
Kuala Lumpur
Singapore
Data
Center
Redmond
Data
Center
Bismarck
Boston
Oregon
Tucson
Charlotte
Dallas
Smyrna
Puerto Rico
Mexico
BogotaVenezuela
Medellin
Ecuador
Egypt
Ivory Coast
Brazil
Chile Uruguay
Argentina
With the Windows 2000 domain model



Kenya
Peru
Indonesia
Australia
New Zealand

UAE
Single forest for ‘corporate’
A root domain with 13 child domains
1.1 million objects, 19GB DIT for Global Catalog
South Africa
Microsoft Confidential
Key Benefits


14 domain databases versus 433
13 essential trusts versus 5000


Far fewer domain controllers


Was 2 (minimum) per resource domain
Simpler DNS management


No trust “rot”
Integrated DNS managed as part of Active Directory
New capabilities



Group Policy makes hundreds of applications easy
to install
“Find printers” solves a universal headache
Simplified corporate application development
Microsoft Confidential
What We Learned
Norway
Finland
Poland Russia
DenmarkSweden
Ireland
Holland Czech Rep
Germany
England Belgium
Austria
France Switzerland
Spain
Hungary
Italy
Portugal
Turkey
Greece Israel
Morocco
Data
Center
Korea Japan
China
Taiwan
Hong
New Delhi
KongPhilippines
Bombay
Thailand
Bangalore
Kuala Lumpur
Singapore
Data
Center
Redmond
Data
Center
Bismarck
Boston
Oregon
Tucson
Charlotte
Dallas
Smyrna
Puerto Rico
Mexico
BogotaVenezuela
Medellin
Ecuador
Peru
Indonesia
Australia
New Zealand
Active Directory works as intended…




Ivory Coast
UAE
Kenya
Brazil
Chile Uruguay
Argentina

Egypt
Replicates efficiently across WANs
Supports very large numbers of replicas
Stores very large numbers of objects
Is secure down to the attribute level
South Africa
Microsoft Confidential
What Else We Learned

Technical






Potential group replication collisions
Replica and GC creation can take a long time
Migration tools need to be more complete
Monitoring requires scripting and 3rd-party tools
Deploying multiple forests should be simpler
Non-technical




Windows NT  Windows 2000 = paradigm shift
Cross-group planning requirements and
irreversible decisions lengthen planning cycles
DNS configuration should be simpler
Need “prescriptive” versus “descriptive” content
What We’re Doing In
Windows .NET

Microsoft Confidential
To ease deployment



No-GC logon for branch office deployments
Create replica from media
Replication improvements





Per-value replication for group membership *
Eliminate limitation in number of sites through
improved topology generation algorithm *
No full sync when extending the GC partial attribute set
Eliminate 5000 member group membership limitation *
Updated Active Directory Migration Tool (ADMT)

Password migration
* Requires Windows .NET forest functionality level
What We’re Doing In
Windows .NET

Microsoft Confidential
To improve manageability



Domain rename * and domain controller rename
Cross-forest trust *
DNS improvements




Built-in diagnostics in DCPROMO
Stub zones and conditional forwarding
Control client settings through Group Policy
Improved admin tools



Drag and drop
Multi-select and edit users
Command line administration tools
* Requires Windows .NET forest functionality level
What We’re Doing In
Windows .NET

Microsoft Confidential
Things to keep in mind



Windows 2000 and Windows .NET Active
Directory are fully interoperable
Some features are not enabled until all
domain controllers in a forest are
upgraded to WIndows .NET
None of the features in Windows .NET
require you to stop or redesign your
current deployment
Microsoft Confidential
The Enterprise Directory

Enterprise directory characteristics




Needs to “join” data from many sources


Repository of consolidated information from
many sources, usually about people
Used for centralized management and
provisioning
Intended for reuse by many applications
NOS, ERP, databases, PBXs, more…
Key technology: metadirectory

Pioneered by Kim Cameron at Zoomit Corp.
Microsoft Confidential
The Enterprise Directory

Active Directory design choices




Scriptable access via ADSI
Low-level access via LDAP C API
Extensible schema
Microsoft acquired Zoomit in July 1999




Position Active Directory as an Enterprise
directory
Make it easier to integrate Active Directory
with other directories
Provide platform for directory-centric
“provisioning”
Simplify multi-forest operation
Microsoft Confidential
Customer Example:
ICL-only
information
All computers across
the enterprise
Microsoft NT
>50,000 accounts
TRACS
Exchange 5.5
26,000 users
NT
Domains
X.500
Employees/contractors
18,000 records (in SQL)
Human
Resources
Metaverse
Active Directory
>10,000 Users
Active
Directory
Exchange
5.5
MMS

Self-Service Web
Application

> 50,000 users and more than
80 connected directories under
management by MMS
Active Directory is provisioned
for users automatically
Microsoft Confidential
Active Directory And Exchange


Active Directory replaces Exchange directory
Integrates Windows and Exchange concepts






Mailboxes  Users
Custom recipients  Users and Contacts
Distribution lists  Groups
Repository for Exchange configuration
Security authority for Exchange data
and applications
Shared topology using Active Directory sites
Microsoft Confidential
What We Learned

Customers consolidating NOS and Enterprise

Applications piggyback on NOS infrastructure



Exchange 2000
Public Key Infrastructure
MMS works as intended…




Supports connectivity to wide range of directories,
applications, databases and ‘other’
Able to build and maintain ‘joined’ namespace
‘Converges’ even after connected directory failures
MMS 2.2 solutions available via 30+ partners

Microsoft, Compaq, DeLoitte, ePresence, Lucent, more…
Microsoft Confidential
What Else We Learned

Technical




Broad scale-out of NOS directory puts constraints
on applications: no big data, no volatile data
MMS connector development and configuration not
as easy as we would like
MMS programmability, scalability could be better
Non-technical

Consolidation easier in small companies, but may
be more difficult in larger companies



Messaging group has new dependency on NOS group
Multiple NOS forests common for autonomy, isolation;
MMS is crucial in these situations
Many “Application directories”: independent
directories tied to an instance of an application
What We’re Doing In
Windows .NET

Improved standards support



Aux classes
Virtual List View
Improved flexibility for developers


Schema deactivate
Application partitions




Microsoft Confidential
Container with arbitrary replication scope
Suitable for large and/or volatile data
DSML 2.0: mapping of LDAP to http/XML
“Resource forest” as application directory
Microsoft Confidential
Summary
“Over the long term, Active Directory will accelerate
the directory’s progress toward commodity status
which will put it on part with TCP/IP as an essential
component of the baseline network services
infrastructure” -- The Burton Group

Active Directory is:



Engineered to meet your needs now and for a
long time to come
Ready to deploy now
We’re delivering on that vision now and it
gets better in Windows .NET
Microsoft Confidential
Best Practice Active
Directory Design For
Managing Windows
Networks
Microsoft Confidential
What Is Active Directory
Design?

Creating structure around objects
Microsoft Confidential
Design Process
1.
2.
Determine number of forests
Forest design




Domain design
DNS design
Organizational unit design
Site topology
Microsoft Confidential
What Is A Forest?


An instance of Active Directory
A collection of partitions called domains





Sharing centrally-controlled schema
Sharing centrally-controlled configuration
Global catalog for easy searching
Complete trust
Security and administrative boundary
Microsoft Confidential
Best Practices Forest Model
Model #1: Centralized
Division 1

Division 2
Division 3
Single centralized DS infrastructure
Microsoft Confidential
Best Practices Forest Model
Model #2: Subscription
Division 1

Division 2
Division 3
Opt-in/out of centralized infrastructure
Microsoft Confidential
Best Practices Forest Model
Model #3: Distributed
Division 1

Division 2
Division 3
Separate DS infrastructures for each
autonomous division
Microsoft Confidential
Forest Design

Each forest owner proceeds with
independent forest design




Domain design
DNS design
Organizational Unit design
Site topology
Microsoft Confidential
Domain Design
What is a Domain?

A domain is a partition of a forest



Replication boundary
Administrative boundary
Enable directory to scale out


Over slow or congested networks
Limit where data is replicated
Microsoft Confidential
Best Practices
Domain Model
Dedicated Root Domain
corp.ellipsis.dot


New branch of DNS:
<prefix>.<existing_name>
Admin users only
One Level of Child
Domains

noam
ds
eur

Single, or
Geographic
Microsoft Confidential
Best Practices
Domain Model

Dedicated root



One level of domains



Enables easy transfer of forest ownership
Isolate forest admins from ordinary admins
No strong need for multiple trees or disjoint namespace
No strong need for grandchild or deeper nesting
Geographic partitioning



Map well to network/WAN layout
Map well to organization of global IT group
Stable - geography is relatively unchanging
Microsoft Confidential
Best Practices Model
Say No to Organizational Domains

Autonomous org may want own domain



Unlikely that forest owner trusts org
domain owner - forest owner accountable
for service delivery in whole forest
Unlikely that org domain owner trusts
other org domain owners – after all, wanted
domain in order to stay autonomous!
Autonomy can ONLY be achieved by
creating a separate forest
Microsoft Confidential
Domain Design Process
1.
2.
3.
4.
5.
Design forest root domain
Select single or regional domain model
If regional model, define regions
Define origin and name of each domain
Map remaining Windows NT domains to
Active Directory domains for
consolidation
Microsoft Confidential
Sizing Guidelines
Single Global Domain
Minimum bandwidth
on global network
(kbps)
9.6
14.4
19.2
28.8
38.4
56 (or higher)
Create single global
domain no larger than
(# of users)
20,000
30,000
40,000
50,000
75,000
100,000
* Assumes 10% of channel available for replication (see Appendix)
* Approximation only, not a substitute for lab testing
* Applies to forests up to 100,000 users - larger forests are possible
Microsoft Confidential
Domain Design Example
MUD
MUD
MUD
60,000 users
slowest link = 28.8 kbps
MUD
RD
RD RD
RD
MUD
RD
RD
RD
RD
Microsoft Confidential
Replication Sizing
Assumptions








Net 10% of channel used for replication
All DCs are GCs
Incoming new user rate 20% per year
Outgoing user rate 15% per year
Dominant factor in replication traffic is
group membership changes
1:1 ratio users to computers
DS-integrated DNS in use
DNS scavenging in use
Microsoft Confidential
DNS Design
How does Windows 2000 use DNS?

Windows 2000 uses DNS as a domain
locator and name-to-IP translator


Domain controllers are registered in DNS
Clients query DNS to locate DCs


Analogous to Internet mail (the MX record)
Better-scaling long-term replacement
for NetBIOS Name Services (aka WINS)
Microsoft Confidential
DNS In A Nutshell
zone
‘.’
(root)
forwarding
dot
iteration
client
Q: What is the IP
address of
www.ellipsis.dot?
authoritative for
ellipsis.dot
delegation
ellipsis
Microsoft Confidential
DNS Design
Elements of a DNS Design

DNS server configuration




Server placement
Zone placement and type
Method of recursive name resolution
DNS client configuration


Computer naming
Resolver configuration
Microsoft Confidential
Best Practices DNS Model
Server Configuration
Server placement:
 Run Windows 2000
DNS on all DCs
Method for recursion:
 Use same method as
current DNS servers
corp.ellipsis.dot
corp
noam
_msdcs
noam
_msdcs
ellipsis.dot
Zone placement:
 Each domain hosts DS-integrated
zone of name of domain, secure
update, scavenging enabled
 Forest root also hosts
_msdcs.<fr> zone

Child domain hosts secondary
copy of _msdcs.<fr> zone
through incremental zone transfer
Microsoft Confidential
Best Practices DNS Model
Resolver Configuration

Windows 2000 clients must be provided
with the IP address of a DNS server



Can be any pre-existing DNS server
Does not have to be Windows 2000 server
Clients will automatically locate correct
DNS server when sending dynamic update
Microsoft Confidential
Organizational Unit Design
What is an Organizational Unit?


Hierarchical structure within a domain
Group objects for management


Delegation of administration
Scope of policy
Microsoft Confidential
Best Practices OU Model
Overview
Service
owner
<domain>
Account
owner
Resource
owner
Users
Computers
Domain
Controllers
<acct>
…<acct>
<res>
Users
Service
Accounts
Computers
Groups Admins
<res>
…<res>
…<res>
Microsoft Confidential
Best Practices Model
Overview

Default containers/OUs


Account OUs



Well-known and built-in users and groups
Used to manage identity and policy
Analogous to Master User Domains
Resource OUs


Used to manage access to resources
Analogous to Resource Domains
Microsoft Confidential
Site Topology Design
What is a Site?

A site is an area of good connectivity





Defined as a set of IP subnets
Clients prefer servers in their site
Intra-site replication optimized to reduce
update latency
Inter-site replication optimized to reduce
bandwidth usage
Sites connected by Site Links
Microsoft Confidential
Site Design Process
1.
2.
3.
4.
Create location map
Place DCs into locations
Map locations to sites
Connect sites with site links
Microsoft Confidential
1. Create Location Map
Hub
Hub
Hub
Hub
Microsoft Confidential
2. Place Domain Controllers

Place forest root DCs



Place regional domain DCs



Into relevant hub locations
Into sites that require autonomous logon
Place each domain’s PDC



Into each hub location
Into locations with DCs from >1 domain
Into well-connected location
With large number of users from domain
Remember physical security
requirements!
Microsoft Confidential
2. Place Domain Controllers
eur (p)
noam (p)
root
root
noam
eur
root
noam
soam
soam
root
soam (p)
eur
Microsoft Confidential
3. Map Locations To Sites
eur (p)
noam (p)
root
root
noam
eur
root
noam
soam
soam
root
soam (p)
eur
Microsoft Confidential
4. Connect Sites With
Site Links

Connect sites according to WAN links



Name site links: <site1>-<site2>
If any site is connected to >20 sites, stop –
consult Branch Office whitepaper
Set site link parameters



Cost: understand failover behavior
Schedule: keep open when possible,
understand impact on replication latency
Interval: based on latency requirements
Microsoft Confidential
Capacity Planning

Deploy enough DCs to satisfy user
demand at a reasonable cost



Too few: poor service
Too many: high cost to deploy, operate
Parameters



Number and speed of CPUs
Memory size
Disk size and configuration
Microsoft Confidential
Impact On Performance
FACTOR
CPU
User Logon
Workstation logon
LDAP search
Replication <10 partners
Replication >10 partners
KCC <200 sites
KCC >200 sites
High
Medium
Variable
Low-Medium
High
Low-Medium
High
PDC role
High
GC role
Variable
Microsoft Confidential
Best Practices

First scale up, then scale out




Scale up: small number of powerful DCs
Scale out: add more DCs to distribute load
Long-term admin cost savings for smaller
number of DCs outweighs short-term
higher purchase cost of powerful DCs
Aim for average CPU utilization <60%
Microsoft Confidential
CPU And Memory
Guidelines
USERS
IN SITE
DCs IN SITE
GCs IN SITE
DED*
<100
No
100 –
500
500 –
1,000
One uniprocessor PIII One
500 Mhz 512 MB
One uniprocessor PIII One
500 Mhz 512 MB
One dual processor
One
PIII 500 Mhz 1 GB
1,000 –
10,000
Two quad processor
PIII Xeon 2 GB
Two
Yes
>10,000
One quad PIII Xeon
2 GB, per 5,000 users
One GC per two Yes
DCs, min of two
Yes
Yes
Microsoft Confidential
CPU And Memory Exceptions




For forests with 100-200 sites, use
multiple processors on all DCs in forest
For sites connected to >10 sites, use
multiple processors on all DCs in site
Single global domain: make all DCs GCs
Use Dedicated PDC configuration for
domains >50,000 users


Lowering priority of DC in locator will keep
“ordinary” requests away
Use same h/w as >10,000 user site
Microsoft Confidential
Disk Guidelines


DC: 0.4 GB per 1,000 users
GC: (DC) + (Sum of store other domains)/2
USERS
IN SITE
<10,000
>10,000
COMPONENT
Operating system
Log files
Database and SYSVOL
Operating system
Log files
Database and SYSVOL
DISK
Single RAID 1 disk
RAID 1
RAID 1
RAID 1 (good)
or RAID 0+1 (better)
Microsoft Confidential
Using Guidelines


Use guidelines as an approximation
More precise results with the ADSizer



Use sizer if you know input parameters
http://www.microsoft.com/windows2000/do
wnloads/deployment/sizer/default.asp
Verify design with lab testing
Microsoft Confidential
Summary






Forest design is politically driven
Domains are geographically-based
Delegate DNS to Active Directory
Use Account OUs and Resource OUs
Site topology reflects network topology
Capacity planning: scale up before out
Microsoft Confidential
Best Practices
For Active Directory™
Deployment
Microsoft Confidential
Active Directory Deployment Phases
Microsoft Confidential
Best Practices For Building
Domain Controllers - Installation




Install server as member server
Install Terminal Service
Install Service Pack 2 plus
additional hot-fixes
Install DNS with operating system



Always use fixed IP addresses
Install Support Tools and Resource
Kit Tools
Install monitoring solution
Microsoft Confidential
Best Practices For Building
Domain Controllers - Promotion



Move machine to it’s final location
Promote DC
Run quality assurance tools





Check event log
Dcdiag
Netdiag
Repadmin
Consider DC pre-staging if large number
of domain controllers has to be build

More information in “Branch Office Deployment”
session
Microsoft Confidential
DNS Integration

DNS client (resolver)



On forest root domain controller: preferred and alternate DNS server
points to a different computer (should be in the same site or close site)
On non-forest root domain controller: preferred DNS server should
be local computer
DNS server

Create delegation entry for new domain controller


Delegation entry consists of two parts, NS record and A record
In <forest-root> DNS zone for regional domains


For domain controllers in the forest root domain





DNS for Active Directory owner in the forest root domain will
do this for you
If DNS already exists, contact DNS owner to create delegation entry
in parent DNS domain
Do this for every forest root DC
If no DNS already exists, dcpromo will automatically create DNS root domain
Zones will be configured after Active Directory is installed on the domain
controller / DNS server
For zone configuration, see “Best Practices for Active Directory Design”
Microsoft Confidential
Installing The Root Domain

Root domain is a special domain



Houses schema and configuration
Center of Kerberos referrals
DNS zone in root domain holds forest wide
resource records



Replication
GCs
Considerations



Operations master and capacity planning
Securing the root domain
Domain controller placement
Microsoft Confidential
Excursion
Backup and Operations Masters



Backup / restore recommendations
Operations masters
Special considerations for restoring
operations masters
Microsoft Confidential
Domain Controller Backup




Backup sufficient number of
domain controllers
Minimum: 2 domain controllers
per domain
Ideally: all domain controllers
Reality: trade-off of
cost vs. easy restore



All DCs on a rotating schedule is
good compromise
At least one per site
Branch Offices: cost of replication might
be higher than cost for restore
Microsoft Confidential
Domain Controller Restore
Best Practices to bring DC online again

NEVER restore a DC on a private network, if this DC is the

only DC on the private network
Best practice



Move DC to private network
Restore DC (do not reboot)
Move second DC to same private network






Second DC should be direct replication partner
Make sure that this DC is up-to-date
Reboot restored DC
Replicate between DCs (force if necessary)
Move both DCs to production network again
If DC is restored on production network, force replication
immediately after restore



Especially if restored DC is only online DC in a site
Use site-services snap-in (or any other tool) to enforce replication
Verify that replication has succeeded
Microsoft Confidential
Forest Operations Master

Schema master


Used for schema extensions
(Exchange 2000, application schema
extensions)
Domain Naming Master

Needed when new domain is added
to forest
Microsoft Confidential
Domain Operations Master

PDC operations master


Used for replication to downlevel domain controllers
Used by downlevel clients for write operations in the directory


Used for password forwarding when users change passwords






All client operating systems versions, not for clients
Preferred server for group policy changes
Changes for Domain DFS
Subnet master browser
Time service
RID pool owner




User password changes, workstation password changes
Assigns RID pools to all other domain controllers
Needed for bulk security principal additions
Must be online for Intra-forest migrations
Infrastructure master

Updates references to objects that moved between domains
Microsoft Confidential
Operations Masters Dependencies

Forest wide operations master roles



Schema master: low performance impact
Domain naming master: low performance
impact, must be GC
Domain wide operations master roles



PDC operations master: low performance
impact (root domain only)
RID pool operations master: low
performance impact
Infrastructure master: low performance
impact, must not be a GC
Microsoft Confidential
Best Practices For
Operations Masters

First DC in forest root domain is a GC and has all
operation master roles by default




Leave GC service and forest wide operation master roles
on first DC
Do not add GC service to second DC in forest root
domain and move all domain wide operations
master roles to second DC
Monitor these two DCs very closely
For each operations master



Have “stand-by” operations master in same site
Create manual connection object between operations
master and stand-by
Forest root domain

Forest operations master can be stand-by for domain
operations master and vice versa
Microsoft Confidential
Operations Master Offline
Scenarios

If you don’t need the operations master online,
do nothing





Having the Schema, Domain Naming master and
Infrastructure master off-line for a short time does not
affect the DS
RID pool owner should be brought back within hours, but
bulk-operations (migrations) might need it earlier
PDC emulator must be online
If operations master down-time is planned and either
very long, or master is needed, transfer operations
master role
If operations master down-time is unplanned and
master is needed, seize operations master role to
stand-by operations master
Microsoft Confidential
How to Bring Operations
Master Back Online

This is mandatory in the following cases




Restore of the operations master
Bringing the operations master back after role was seized
If you cannot follow these instructions, do not bring operations
master online again
Checklist



Move old operations master to private network
Restore old operations master if necessary (do not reboot)
Move stand-by operations master (which now has the roles) to
private network



Reboot restored DC (=old operations master)
Replicate between DCs (force if necessary)



Make sure that this DC is up-to-date
This will update the operations master with live data (RID pool)
Transfer all operations master roles to original operations
master again
Move both DCs to production network again
Microsoft Confidential
Securing The Root Domain

At least two domain controllers


Back-up of both DCs



Best in different locations
One can have corrupted data,
which could end up on a back-up tape
Corrupted data never replicates out
Domain controller availability

Depends on deployment



Root DCs are used for Kerberos referrals, make sure that
some root DCs are always online
If _msdcs.<forest-root> is not delegated, make sure that
enough root DCs are on-line for DNS name resolution of
forest wide resource entries
For forest operations, the operations master
must be on-line. No frequent operation
Microsoft Confidential
Root Domain – Best Practices

On the first root DC






On second root DC





Promote DC, let dcpromo configure DNS
Manually create _msdcs.<forest-root> DNS domain
Restart Netlogon service to re-register entries
Add DNS delegation entries
Get monitoring and back-up in place
Promote DC
Transfer all domain wide operations master roles
Get monitoring and back-up in place
Do not add GC service
On all additional root DCs



Promote DC
Get monitoring in place
Do not add GC service



Reduces number of replication connections to DCs in other domains
Deploy forest root DCs to all hubs
Configure DNS clients to point to other DCs as preferred and alternate
DNS servers
Microsoft Confidential
Creating Regional Domains


Selecting initial source for directory data
Considerations




Operations masters
Capacity planning for DCs / GCs
Should DCs be GCs?
Preparing OUs for data owners


Creating OU structure
Delegating rights
Microsoft Confidential
Operations Masters In
Regional Domains

PDC Emulator

Provides some CPU intensive operations





User password changes are forwarded to PDC Emulator
immediately
When user types wrong password at logon, request is forwarded
to PDC Emulator
Replicates to down-level DCs in mixed mode domains
Only place where down-level clients can change passwords
In domains >50,000 users, machine should be dedicated to role


Lower priority in SRV records
HKEY_LOCAL_MACHINE\System\CCS\Services\Netlogon\
Parameters


LdapSrvPriority: 0 = highest = default setting
Set to higher value, like 10
Microsoft Confidential
Operations Masters In
Regional Domains

RID pool owner



Distributes RID pools to other DCs
Low performance impact
Infra-structure master



Updates links to objects after domain
move operations
Low performance impact
Must not be a GC
Microsoft Confidential
Operations Masters –
Best Practice



Leave all operations master roles on
first domain controller
Never put GC on this domain controller
Monitor closely
Microsoft Confidential
Should DCs Be GCs?


Domain controller placement and Global
Catalog placement are part of AD design
Consider additional GCs

DCs that are most likely inter-site
replication sources (minimizes number
of connection objects)
Microsoft Confidential
Creating New Regional Domain




Create DNS delegation from
root domain
Install first domain controller
Configure client to point to itself as
primary DNS server and any other DNS
server as alternate DNS server
Install additional domain controllers
Microsoft Confidential
Domain Upgrade
Order of Upgrade

Start with all NT 4.0 environment


Upgrade domain controllers first


Workstation and server deployment independent from
Active Directory deployment
No worries
Upgrade NT4 clients to W2K first

W2K clients in NT 4 domain only authenticated by PDC
SP2 Q272348
Upgrade clients in mixed mode mixed
version domain




Special care must be taken (piling on scenario)
Considerations


RAS servers first
LMRepl export server last
Microsoft Confidential
Upgrade Considerations
Stages of Upgrade
Upgrade
MUD
MUD
MUD
PDC and none
of BDCs
upgraded
PDC and BDCs
upgraded,
switch to native
mode not made
MUD
PDC and BDCs
upgraded,
switch to native
mode made
Migration
Pre-migration
Environment
Windows 2000
Native Mode
Microsoft Confidential
Upgrade Considerations
Stages of Upgrade - PDC First








Now in mixed-mode
Objects copied from SAM to AD
Windows 2000 DC PDC Emulator
Still replicates to Windows NT BDCs
Windows NT BDCs can still be added
Fallback: If all Windows 2000 DCs offline, one
Windows NT 4 BDC can be promoted to PDC –
domain is now Windows NT 4 domain again
No effect on SIDs
If PDC cannot be upgraded (hardware)



Install new BDC
Promote BDC to PDC
Upgrade
Microsoft Confidential
PDC Overload Scenarios

Different components put load on
PDC role master








Domain DFS and NT4 SP6 clients
PDC registration in WINS
Sort order of domain 1C entries returned by
WINS
Some object picker versions go to PDC only
Pass-through authentication to PDC
Win2000 clients only authenticated by PDC in
NT4 domain
Kerberos logon goes to Windows 2000 DCs only
In small domains, this is not an issue
Microsoft Confidential
Upgrade Considerations
Stages of Upgrade - BDCs Next

Moving or demoting BDCs new in
Windows 2000


Upgrade to Windows 2000
If resource domain should remain
Windows NT 4 domain, but BDCs have
to be moved





Take BDC offline
Promote to PDC
Upgrade
Demote to standalone / member server
Move to new domain
Microsoft Confidential
Best Practice
Recommendations

Monitor your Active Directory


Replication and replication latency
Important domain controllers



Performance


Replication sources in data centers (hub sites)
PDC and RID pool operations master
Poor performance is an indicator that something
is wrong
Avoid panic trouble-shooting


Increasing replication schedule to
troubleshoot issues
Deleting objects in the DS in the hope that they get
somehow re-generated
(Windows NT 4 practice)
Microsoft Confidential
Best Practice
Recommendations

Test, test, test




Not only the product, test your procedures
Use scripts for common tasks and to document
operations (delegation)
Spending time and money on testing pays off
during the deployment and the operation of AD
Do not under-engineer hardware


Plan for future growth
If machines become increasingly under stress,
operations might fail and retries might add
to more stress
Microsoft Confidential
For More Information
Best Practices Online

Best Practice Active Directory
Deployment for Network Operating
System Environments


http://www.microsoft.com/windows2000/
technologies/directory/default.asp
Look in the Planning & Deployment section
Microsoft Confidential
Microsoft Confidential
© 2002 Microsoft Corporation. All rights reserved.