Difference Between Category 6 cable & Category 5e cable

• Category-6 cable, commonly referred to as Cat-6, is a cable standard for Gigabit Ethernet and other network protocols that is backward compatible with the Category 5/5e and Category 3 cable standards.
  
• Cat-6 give good control over crosstalk and system noise.
  
• Cat-6 cable standard provides performance of up to 250 MHz and is suitable for
  10BASE-T / 100BASE-TX and 1000BASE-T (Gigabit Ethernet)
  
• Cat-6 is normally terminated in 8P8C modular connectors, often incorrectly referred
  to as “RJ-45″ electrical connectors.
  
• CAT-6 cable contains four pairs of copper wire and unlike CAT5, utilizes all four pairs.
  
• Cat-6 can support 10 Gbit/s applications (especially 10GBaseT) up to a maximum distance of 100 meters.
  
• Twisted pair cable like CAT6 comes in two main varieties, solid and stranded. Solid CAT6 cable supports longer runs and works best in fixed wiring configurations like office buildings. Stranded CAT6 cable, on the other hand, is more pliable and better suited for shorter-distance, movable cabling such as “patch” cables.
  
• Cat-5e cable is an enhanced version of Cat 5 that adds specifications for far end crosstalk.
  
• Cat-5e cables are still limited to a maximum of 100 m (328 ft) in length (normal
  practice is to limit fixed (”horizontal”) cables to 90 m to allow for up to 5 m of patch cable at each end, this comes to a total of the previous mentioned 100m maximum).
  
• Although CAT5 cable usually contains four pairs of copper wire, Fast Ethernet
  communications only utilize two pairs. A newer specification for CAT5 cable - CAT5 enhanced (CAT5e) - supports networking at Gigabit Ethernet[ speeds (up to 1000 Mbps) over short distances by utilizing all four wire pairs, and it is backward compatible with ordinary CAT5.

Why to use VLAN Trunking Protocol (VTP)

• VLAN Trunking Protocol (VTP) is a Cisco Layer 2 messaging protocol.
• Manages the addition, deletion, and renaming of VLANs on a network-wide basis.
• VTP reduces administration in a switched network.
• When you configure a new VLAN on one VTP server, the VLAN is distributed through all switches in the domain. This reduces the need to configure the same VLAN everywhere. To do this VTP carries VLAN information to all the switches in a VTP domain.
• VTP advertisements can be sent over ISL, 802.1q, IEEE 802.10 and LANE trunks.
• VTP ensures that all switches in the VTP domain are aware of all VLANs.
• VTP pruning is a feature used to eliminate (or prune) the unnecessary traffic.

Security Measurements for Network Attacks

• Monitor networks boundaries for attacks.
• Ensure that routers are not converting layer 3 broadcasts into layer 2 broadcasts. The Cisco command to disable this is: no ip directed-broadcast. This is the default setting for routers that use IOS version 12.0 or greater.
• Restrict routers to allow only the use of ports that are necessary for the site to function.
• Disable unnecessary or optional services (i.e.: Client for Microsoft Networks on a IIS server)
• Enable TCP/IP filtering and restrict access to only the ports that are necessary for the server to function. (see Knowledge Base article 150543: WinNT, Terminal Server, & Exchange Services Use TCP/IP Ports for a list of ports that Windows services use)
• Unbind NetBIOS over TCP/IP where it is not needed.
• Configure static IP addresses and parameters for public adapters.
• Configure registry settings for maximum protection

What to Backup in Windows Server 2003 Active Directory

To backup Active directory you back up the System State on Domain Controller servers.

The System State contains

• The local Registry,
  
• COM+ Class Registration Database,
  
• the System Boot Files,
  
• certificates from Certificate Server (if it’s installed),
  
• Cluster database (if it’s installed),
  
• NTDS.DIT,
  
• and the SYSVOL folder.

Understand IPv6 addresses

IPV4:

• IPv4 addresses are represented in dotted-decimal format.
• 32-bit address is divided along 8-bit boundaries.
• Each set of 8 bits is converted to its decimal equivalent and separated by periods.

IPV6:

• For IPv6, the 128-bit address is divided along 16-bit boundaries
  
• Each 16-bit block is converted to a 4-digit hexadecimal number and separated by colons.

IPv6 Unicast:

This is similar to the unicast address in IPv4 – a single address identifying a single interface.

There are four types of unicast addresses:

• Global unicast addresses, which are conventional, publicly routable address, just like conventional IPv4 publicly routable addresses.
  
• Link-local addresses are akin to the private, non-routable addresses in IPv4
  (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16). They are not meant to be routed, but confined to a single network segment.
  


• Unique local addresses are also meant for private addressing, with the addition of
  being unique, so that joining two subnets does not cause address collisions.
  
• Special addresses are loopback addresses, IPv4-address mapped spaces

Multicast:

Multicast in IPv6 is similar to the old IPv4 broadcast address a packet sent to a multicast address is delivered to every interface in a group. The IPv6 difference is it’s targeted instead of annoying every single host on the segment with broadcast blather, only hosts who are members of the multicast group receive the multicast packets. IPv6 multicast is routable, and routers will not forward multicast packets unless there are members of the multicast groups to forward the packets to.

Anycast:

An anycast address is a single address assigned to multiple nodes. A packet sent to an anycast address is then delivered to the first available node. This is a slick way to provide both loadbalancing and automatic failover. The idea of anycast has been around for a long
time; it was proposed for inclusion in IPv4 but it never happened.

Several of the DNS root servers use a router-based anycast implementation, which is really a shared unicast addressing scheme. (While there are only thirteen authoritative root server names, the total number of actual servers is considerably larger, and they are
spread all over the globe.) The same IP address is assigned to multiple interfaces, and then multiple routing tables entries are needed to move everything along.

IPv6 anycast addresses contain fields that identify them as anycast, so all you need to do is configure your network interfaces appropriately. The IPv6 protocol itself takes care of getting the packets to their final destinations. It’s a lot simpler to administer than shared unicast addressing.

How to Create VLAN (Virtual Local Area Network)

A virtual LAN, commonly known as a VLAN, is a group of hosts with a common set of requirements that communicate as if they were attached to the Broadcast domain, regardless of their physical location. A VLAN has the same attributes as a physical LAN, but it allows for end
stations to be grouped together even if they are not located on the same network switch. Network reconfiguration can be done through software instead of physically relocating devices.

VLAN Creation:

Switch(config)# vlan 10

Switch(config-vlan)# name anyname

Access Port Configuration:

Switch(config-if)# switchport mode access

Switch(config-if)# switchport nonegotiate

Switch(config-if)# switchport access vlan 10

Switch(config-if)# switchport voice vlan 15

Trunk Port Configuration:

Switch(config-if)# switchport mode trunk

Switch(config-if)# switchport trunk encapsulation dot1q

Switch(config-if)# switchport trunk allowed vlan 10,15-20

Switch(config-if)# switchport trunk native vlan 10