System Administrator

Active Directory Active Directory is a centralized and standardized system, stores information about objects in a network and makes this information available to users and network administrators. Domain Controller In an Active Directory forest, the domain controller is a server that contains a writable copy of the Active Directory database, participates in Active Directory replication, and controls access to network resources. Global catalog server A global catalog server is a domain controller that stores information about all objects in the forest. Like all domain controllers, a global catalog server stores full, writable replicas of the schema and configuration directory partitions and a full, writable replica of the domain directory partition for the domain that it is hosting. In addition, a global catalog server stores a partial, read-only replica of every other domain in th e forest. Partial replicas are stored on Global Catalog servers so that searches of the e

CIDR Host  bits Netmask Addresses in subnet Classful  name Typical usage /8 24 255.0.0.0 16777216 = 2 24 Class A (see this  list ) Largest block allocation made by  IANA /9 23 255.128.0.0 8388608 = 2 23 /10 22 255.192.0.0 4194304 = 2 22 /11 21 255.224.0.0 2097152 = 2 21 /12 20 255.240.0.0 1048576 = 2 20 /13 19 255.248.0.0 524288 = 2 19 /14 18 255.252.0.0 262144 = 2 18 /15 17 255.254.0.0 131072 = 2 17 /16 16 255.255.0.0 65536 = 2 16 Class B /17 15 255.255.128.0 32768 = 2 15 ISP  / large business /18 14 255.255.192.0 16384 = 2 14 ISP / large business /19 13 255.255.224.0 8192 = 2 13 ISP / large business /20 12 255.255.240.0 4096 = 2 12 Small ISP / large business /21 11 255.255.248.0 2048 = 2 11 Small ISP / large business /22 10 255.255.252.0 1024 = 2 10 /23 9 255.255.254.0 512 = 2 9 /24 8 255.255.255.0 256 = 2 8 Class C Large  LAN /25 7 255.255.255.128 128 = 2 7 Large LAN /26 6 255.255.255.192 64 = 2 6 Small LAN /27 5 255.255.255.224 32 = 2 5 Small LAN /28 4 255.2

How to Troubleshooting Windows Server 2008 R2 & 2012 Failover Clusters. I was configuring windows 2012 cluster on xen cloud platform and found this troubleshoot guide from microsoft blog, really usefull and easy to find an error. How to get to the root of the problem In "Troubleshooting Windows Server 2008 R2 Failover Clusters," the locations and tips for where you can go to get the data you need to troubleshoot a problem. Now I'll discuss some of the improvements made to the troubleshooting tools for  Windows Server 2012  failover clusters and show you how to take advantage of those tools. Introducing the New Event Channels There are some new event channels for failover clustering to help with troubleshooting. Figure 1 shows all the available channels. Figure 1: Event Channels for Failover Clustering in Server 2012 Note that the events are specific to the node you're on. Knowing the purpose of each event channel can help you find the e