When designing for an existing infrastructure, take into account the configuration and functionality (or lack thereof) of existing servers

1
(Skill 1)
Examining the Current File, Print, and
Application Servers

• When designing for an existing infrastructure,
  take into account the configuration and
  functionality (or lack thereof) of existing
  servers
• File servers
• Print servers
• Application servers

2
(Skill 1)
Examining the Current File, Print, and
Application Servers (2)

• File servers
• Often the most overlooked type of server
• Disk subsystem performance and network
  connectivity are of primary importance

3
(Skill 1)
Examining the Current File, Print, and
Application Servers (3)

• File server disk subsystems
• Typically use some form of PCI bus
• Server motherboard determines which PCI
  specification the system is capable of using
• Performance of disk subsystem
• Cannot exceed bus performance
• Because all subsystems share the same bus, the
  maximum achievable transfer rate is usually
  slightly less than half of the maximum
  theoretical rate for the bus

4
(Skill 1)
Examining the Current File, Print, and
Application Servers (4)

• File server disk subsystems
• For redundancy and fault tolerance, must use some
  form of RAID
• RAID 5 with a hardware controller
• RAID 01 (RAID 10)
• RAID 0 provides exceptional speed, but no
  redundancy

5
(Skill 1)
Examining the Current File, Print, and
Application Servers (8)

• Print servers
• Disk space and performance are of primary concern
• Network adapter also an area of major concern to
  maximize performance
• RAM and processor needs, while not unimportant,
  are not as a major concern in comparison to
  storage and network connectivity needs
• Additional considerations include all integration
  and software configuration concerns

6
(Skill 1)
Examining the Current File, Print, and
Application Servers (9)

• Application servers
• Needs vary greatly depending on specific
  application
• Best to use a pilot to determine needs of server,
  if at all possible
• If a pilot is not feasible, do extensive research
  on the needs and limitations of the server (check
  for vendor white papers)

7
(Skill 1)
Figure 2-1 Important subsystems for file servers
8
(Skill 1)
Figure 2-2 Examining different disk subsystem
options
9
(Skill 1)
Figure 2-3 Calculating bandwidth needs
10
(Skill 1)
Figure 2-4 Important subsystems for print servers
11
(Skill 2)
Examining the Current DNS Infrastructure

• Domain Name System (DNS)
• The core name resolution service in Windows
  Server 2003
• Begin analysis of core network services by
  analyzing DNS
• Must be designed and configured properly or
  Active Directory performance may be severely
  impacted

12
(Skill 2)
Examining the Current DNS Infrastructure (2)

• Important factors in analyzing the current DNS
  infrastructure
• Existing network operating system
• Versions of DNS server services in place and
  their capabilities
• Hardware currently in place for DNS services
• Current level of redundancy
• Forwarding strategy for current DNS infrastructure

13
(Skill 2)
Examining the Current DNS Infrastructure (3)

• Important factors in analyzing the current DNS
  infrastructure
• Current zone and domain configuration
• DNS replication topology
• Current level of integration with WINS, DHCP, and
  Active Directory
• Current DNS client configuration

14
(Skill 2)
Examining the Current DNS Infrastructure (4)

• Existing network operating system
• Network operating systems used for DNS services
• Unix/Linux
• Windows NT
• Windows 2000 Server
• Windows Server 2003

15
(Skill 2)
Examining the Current DNS Infrastructure (5)

• Versions of DNS server services in place
• Unix and Linux DNS servers typically run a
  version of Berkeley Internet Name Domain (BIND)
• BIND version 4.9.7 is minimum version capable of
  supporting SRV records, so any earlier version
  cannot be used to host DNS domains for Active
  Directory
• BIND version 8.1.2 and higher versions are
  recommended as they include support for DNS
  dynamic updates
• BIND version 8.1.1 also supports DNS dynamic
  updates, but is not recommended due to flaws
• BIND does not support Active Directory integrated
  zones

16
(Skill 2)
Examining the Current DNS Infrastructure (6)

• Versions of DNS server services in place
• Windows NT DNS servers
• Do not support SRV records, dynamic updates,
  Active Directory integrated zones, or secure
  updates
• Should nearly always be upgraded or migrated to
  Windows 2003 Server or Windows 2000 Server

17
(Skill 2)
Examining the Current DNS Infrastructure (13)

• Key areas of current zone and domain structure
• Use of private DNS names (such as .local)
• Raises same issues as use of unregistered public
  domain names
• Solutions
• Modify forwarding strategy
• Configure DNS servers in each subdomain to host a
  secondary copy of the root zone file
• Disadvantage may increase total zone replication
  traffic
• Advantages provides less remote query traffic
  and higher levels of availability for the domain
  root

18
(Skill 2)
Examining the Current DNS Infrastructure (14)

• Key areas of current zone and domain structure
• Placement of primary DNS servers for each zone
• For security reasons, always locate primary name
  servers behind a firewall
• Ensure they are in a location that facilitates
  efficient zone transfers
• Ensure that adequate redundancy for each zone
  exists
• Ensure at least two servers host a copy of each
  zone file

19
(Skill 2)
Examining the Current DNS Infrastructure (16)

• Level of integration between DNS and other
  network services
• Integration with WINS, DHCP, and Active Directory
  (if already present) are of primary concern
• If DNS is integrated with WINS, determine whether
  WINS should remain in place in new design
• For dynamic DNS to function, DNS must be
  integrated with DHCP
• Determine if Active Directory integrated zones
  are currently being used since they have
  different storage, security, operating system,
  and replication needs

20
(Skill 2)
Figure 2-6 Supported features of different DNS
server platforms
21
(Skill 2)
Figure 2-8 An example of a forwarding structure
22
(Skill 2)
Figure 2-9 An example of an inefficient
forwarding strategy
23
(Skill 2)
Figure 2-11 An example DNS hierarchy
24
(Skill 2)
Figure 2-15 An example of when an unusual
replication topology is in use
25
(Skill 3)
Examining the Current WINS Infrastructure

• Windows Internet Naming Service (WINS)
• An important service in most legacy networks
• Resolves NetBIOS names, used by down-level
  (pre-Windows 2000) operating systems, into IP
  addresses
• When examining existing NetBIOS name resolution
  infrastructure, consider the need for NetBIOS
  name resolution

26
(Skill 3)
Examining the Current WINS Infrastructure (2)

• Windows Internet Naming Service (WINS)
• Reasons for maintaining NetBIOS name resolution
• Use of down-level client or server operating
  systems
• Use of legacy applications that rely on NetBIOS
  name resolution
• Use of network services, such as Distributed file
  system (Dfs), in Windows 2000 that rely on
  NetBIOS naming

27
(Skill 3)
Figure 2-16 NetBIOS name resolution methods
28
(Skill 4)
Examining the Current Remote Access
Infrastructure

• Primary methods of remote access
• Dial-in remote access
• Requires enough POTS connections/modems or ISDN
  connections/adapters to support the required
  number of simultaneous users
• Virtual private network (VPN) remote access
• Requires connectivity with enough bandwidth,
  ability to encrypt and decrypt packets fast
  enough, and the ability to support the required
  number of simultaneous users
• May require router, firewall, and specialized
  network adapters

29
(Skill 4)
Examining the Current Remote Access
Infrastructure (2)

• Methods used to provide authentication,
  authorization, and accounting (AAA) services
• Windows-based AAA
• RADIUS-based AAA
• Other considerations
• Private network connectivity requiredtypically
  high
• Performance and availability of current remote
  access solution
• Client configuration

30
(Skill 4)
Figure 2-17 An example VPN architecture
31
(Skill 4)
Figure 2-18 Areas to check for Windows-based AAA
services