Chapter 5 “Configuring Routing and Remote Access (RRAS) and Wireless Networking”

Thursday, February 28, 2013

 Routing is the process of transferring data across an internetwork from one LAN to another.  Routers operate at the third layer of the OSI model, the network layer, and they determine the route that data will take from the source network to the destination network.  Routers can join networks together over extended distances or join dissimilar networks, for example an Ethernet LAN to a Fiber Distributed Data Interface (FDDI) backbone.  Routing protocols can be used to transmit information about the routing topology and which routes can be reached through which router.  Some of the common protocols are, Routing Information Protocol (RIP), Routing Information Protocol version 2 (RIPv2), and Open Shortest Path First (OSPF).  Routers use routing tables to forward packets to the next destination.  When a packet arrives at the router, the router reads the destination and compares it to the information found in the routing table and then forwards the packet to the next destination based on that information.  One of the roles that Windows Server 2008 has to offer is Routing and Remote Access (RRAS).  RRAS provides many different types of remote access connectivity including Dial-Up Networking (DUN), and Virtual Private Networking (VPN), as well as allowing your Windows Server 2008 computer to act as a Network Address Translation (NAT) device.  Windows Server 2008 uses the Network Policy Server (NPS) RRAS role service as a means to check the credentials of someone trying to connect to the server.  Remote Authentication Dial-In User Service (RADIUS) is another third party authentication and authorization role service that can be used in place of NPS.  Wireless mobile devices such as smartphones, tablets, and netbooks, have created a need to secure this type of access.  To accomplish this, the Institute of Electrical and Electronics Engineers (IEEE) developed the 802.1X standard for network access control.  There are three components that 802.1X uses to provide port based security.  The Supplicant, which is the device that is attempting to gain access to the network such as a smartphone or laptop, the Authenticator, which is the component that requests credentials from supplicants, and the Authentication Server, which provides the verification of the authentication credentials.

Chapter 4 “Configuring and Managing the DNS Server Role”

Thursday, February 21, 2013

 The Domain Name System (DNS) role is the role that Microsoft Windows Server 2008 uses for name resolution.  When you send a request through your browser, for example, to a web site like www.yahoo.com, it’s DNSs responsibility to map the URL www.yahoo.com to its IP address so the request can be completed.  A DNS namespace is a tree structured list of host names in a hierarchical order starting with the root, which is unnamed and is represented by a period. Next is the top level domain, for example, .com, .net, or .edu, followed by a second level domain, which are registered to individuals, for example Yahoo (yahoo.com), Microsoft (Microsoft.com), or McHenry County College (mchenry.edu).  For administrative purposes, DNS can be organized into zones.  A DNS zone is a collection of name to IP address mappings in a contiguous portion of the DNS namespace which allows for sharing the workload across many other DNS servers.  A DNS zone can provide name to IP mappings for one or more domains.  If DNS is to provide for multiple domains they must be contiguous, or part of a parent child relationship.  There are three typical zone types that can be configured on a DNS server, the standard primary zone, the standard secondary zone, and the reverse lookup zone.  Windows Server 2003 and 2008 provide a fourth called a stub zone.  A standard primary zone hosts a read/write copy of the DNS zone in which resource records are created and managed.  Only one server can host a master copy of the zone, accept dynamic updates, and process zone changes.  A standard secondary zone is a read only copy of the primary zone and may be stored on one or more servers to provide fault tolerance and load balancing.  A reverse lookup zone can provide the hosts fully qualified domain name (FQDN) when a query contains “what is the host name at the IP address 69.147.76.15 it will return www.yahoo.com.  Finally, a stub zone is a copy of a zone that contains only the resources necessary to identify the authoritative DNS servers for that zone.  A stub zone does not have the same abilities as a secondary zone and should only be used for address redundancy and load sharing.

Chapter 3 “Configuring and Managing the DHCP Server Role”

Thursday, February 14, 2013

  DHCP is the role Windows Server 2008 uses to manage IP addresses.  DHCP functions at the application layer of the Open System Interconnection (OSI) reference model.  The key aspect of DHCP is that it‘s dynamic, meaning  the network is configured to assign IP addresses to any devices connected to the network.  The different message types that DHCP uses to communicate between a client and a server are, DHCPDISCOVER, DHCPOFFER, DHCPREQUEST, DHCPDECLINE, DHCPACK, DHCPNACK, DHCPRELEASE, and DHCPINFORM.  The first of four messages that are used for the initial lease process are DHCPDISCOVER, which is the first message the client sends looking for a DHCP server.  The second message used is DHCPOFFER, which is when the DHCP server receives the DHCPDISCOVER message and replies with a message that contains IP address information for the client.  The third message is DHCPREQUEST, which is the client letting the server know that it will use the IP information supplied by the DHCP server.  The fourth and last message in the initial lease process is DHCPACK, which is the DHCP server acknowledging the client and assigning the IP address information.  The four step process is easier to remember by using the acronym DORA, for DISCOVER, OFFER, REQUEST, and ACK.  DHCP uses scopes to determine which IP addresses are allocated to client computers.  Administrators can create one or more scopes, however, caution must be taken so multiple DHCP servers are not using the same IP addresses.  Windows server 2008 supports automatic or manual backups.  Backing up the database is very important for fault tolerance in case of a DHCP server failure.

Chapter 2 “Installing Microsoft Windows Server 2008”

Thursday, February 07, 2013

 The cornerstone of building a network is installing Windows Server 2008.  Windows Server 2008 can be installed as a full server installation with a graphical user interface (GUI) or as a Server Core installation.  A Server Core installation, new in Windows Server 2008, is a system configuration that contains only the specific facilities required for a specific role and does not have a GUI.  All the configurations start from the command prompt.  After installation is complete the first window to open is the Initial Configuration Tasks window.  From this window you can set the proper time zone, configure networking, provide computer name and domain, enable automatic updating and feedback, download and install updates, add roles, add features, enable remote desktop, and configure Windows firewall.  When you are finished you can close the Initial Configuration Tasks window and the Server Manager window should open next.  From this window you can do various tasks such as add roles, add features, diagnostics, other configurations and storage.  Windows Server 2008 supports two types of hard disks, Basic and Dynamic.  All new disks are initialized as basic disks and can be initialized as Master Boot Record (MBR) or GUID Partition Table (GPT) partitioning.  Installing Server core is similar to installing the full GUI version with the exception of all configurations must be done from the command prompt.