Thursday, 28 July 2016

Frequently used vSphere PowerCLI commands.

Or, vSphere PowerCLI commands used frequently in daily operations.
Or, Some important vSphere PowerCLI commands every VMware Administrators should remember.

List of commands used frequently for daily operations -VMware vSphere PowerCLI







Stay tuned for more.. cheers!

How to check ruining LDAP session on Active Directory server?

Or, Get LDAP session list and counts in Active Directory Server.


Descriptions:
To get the list the list of running LDAP sessions on an Active Directory Server, please follow below steps:

Steps: Open CMD (run as administrator) > Type net session > Hit Enter

Now you will be able to all active sessions as highlighted in below screenshot:














You can use “Net” command for multiple purposes. For more please see the below screenshot:

What is LDAP Session in Active Directory?

Or, LDAP client sessions limit reached, OPManager DC monitoring alert.
Or, What should be the threshold or session limit for LDAP sessions occurs in Active Directory?

Descriptions:
This is a very commonly known and a useful NTDS object counter for Monitoring Active Directory running sessions, which Indicates the total number connected LDAP session by various LDAP clients.

The good way to avoid/ignore this kind of alert, is to configure your monitoring tool to not send any email alert even if the session counters reached to 500-600 or the number of clients that you may have.

YOU NOT NEED TO WORRY: As such there is no specific limit in number for LDAP client’s sessions. The only thing you should care about this is, when the number of clients increased, the number of session will be increased and when the number of session increases, the load on the server increases accordingly.

So, by monitoring these session values, you can actually identify when your almost clients are connected to active directory to have some idea about peak hrs utilization, server resources utilization reasons, CPU/Memory spike for some time duration etc.

Tuesday, 26 July 2016

NDR - Office 365: Your message did not reach some or all of the intended recipients.

Or, the following recipient(s) cannot be reached, Outlook 2013 (Office 365 Server).

Problem Description:
This is a known behavior and it happens rarely due to common issues like wireless connectivity hangs, if outlook did not respond well when you click on send button etc.

The possible reason for the error you are facing could be the user was having some intermittent networking issue that happened to hit at the time the message was submitted. This behavior occurs because of a busy or unreachable Internet Mail server when you connect through your Internet service provider (ISP).

This behavior is by design and the error is expected when network failures occur.
In general, this problem is likely caused by intermittent network connectivity issues, or possibly out-of-resource problem on the client machine. Also refer this link MS reference KB : https://support.microsoft.com/en-us/kb/286106

NDR/Error Screenshot:













Solution:
Re-sending this type of email (Using Send Again button) is the available work around for this issue.
Timely windows update and reboot, up to date drivers etc. can help you in getting rid of such issues if it’s occurrence is very frequent for few of the users.

Monday, 18 July 2016

Internet Routing Protocols : OSPF : Open Shortest Path First

Or, Routing Protocols : OSPF
Or, What is OSPF and How to Configure OSPF?

Descriptions:
OSPF stand for Open Shortest Path First. routers connect the network using internet protocol and OSPF is a routing protocol used to find the best route for packets as they pass through a set of connected networks.

Lab 1.1


How to Configure OSPF ?

Descriptions: OSPF Configuration syntax as follows
Router(config)#router ospf <OSPF Process number>
Router(config-router)#network <Network ID> <Wild Card Mask> area <Area number>
OSPF Process number: Is just a number local to the router only. This value does not ensure be the same on all router within the area. Though, it is better to keep this as same for all routers inside an area for better administration.
Network ID: Is the directly connected network address.
Wildcard mask: Is the inverse of Subnet mask
Area number : Logical group of OSPF network.
Cisco Packet Tracer OSPF Configuration Example : Please see the OSPF Network Topology Using Lab 1.1














Cisco OSPF Network Command for Router 1 
R1>enable
R1#conf t
Enter configuration commands, one per line. End with CNTL/Z
R1(config)#router ospf 1
R1(config-router)#network 10.0.0.0 0.255.255.255 area 0
R1(config-router)#network 20.0.0.0 0.255.255.255 area 0
R1(config-router)#exit
R1#
%SYS-5-CONFIG_I: configured from console by console
R1#














Cisco OSPF Network Command for Router 2 
R2>enable
R2#conf t
Enter configuration commands, one per line. End with CNTL/Z
R2(config)#router ospf 1
R2(config-router)#network 10.0.0.0 0.255.255.255 area 0
R2(config-router)#network 30.0.0.0 0.255.255.255 area 0
R2(config-router)#exit
R2#
%SYS-5-CONFIG_I: configured from console by console
R2#
Cisco OSPF Network Command for Router 3
R3>enable
R3#conf t
Enter configuration commands, one per line. End with CNTL/Z
R3(config)#router ospf 1
R3(config-router)#network 10.0.0.0 0.255.255.255 area 0
R3(config-router)#network 40.0.0.0 0.255.255.255 area 0
R3(config-router)#exit
R3#
%SYS-5-CONFIG_I: configured from console by console
R3#
Cisco OSPF Network Command for Router 4
R4>enable
R4#conf t
Enter configuration commands, one per line. End with CNTL/Z
R4(config)#router ospf 1
R4(config-router)#network 10.0.0.0 0.255.255.255 area 0
R4(config-router)#network 50.0.0.0 0.255.255.255 area 0
R4(config-router)#exit
R3#
%SYS-5-CONFIG_I: configured from console by console
R4#

OSPF Verification and Testing Commands

#Show ip ospf















#Show ospf interface <interfaces>

Why should you audit Group Policy and how do you go about it?

Group Policy gives network administrators the ability to define user, security, and organization-wide policies in bulk throughout the network. However, any minor changes to these policies can have massive implications to the user and to network. Continuous auditing and monitoring of Group Policy ensures that you are constantly aware whenever someone attempts to alter Group Policy or misuse Domain Controllers, member servers or Active Directory computers. In this article we will explain how you can use native tools to perform a basic GPO audit.

Group Policy change auditing using native features:

Change auditing Group Policy using native features can be broken down into three steps:
NOTE: Native auditing is very basic in nature – it may change events and will therefore not be very useful when trying to perform forensic analysis of change events.

Enabling DS Access auditing:
DS Access is enabled by editing the Default Domain Controller Policy using the Group Policy Management Editor. Auditing is enabled for Success and Failure events for the two subcategories— Audit Directory Service Access and Audit Directory Service Changesof the DS Access audit policy.





















Note: To do this, right-click Default Domain Controller Policy and click Edit; when the Group Policy Management Editor appears, expand to Computer Configuration > Policies > Windows Settings > Security Settings > Advanced Audit Policy Configuration > Audit Policies, and select DS Access. Double-click Audit Directory Service Access / Audit Directory Service Access, check the checkbox Configure the following audit events and select Success and Failure. Click Apply; click OK.

Configuring SACL entries for Group Policy Container objects:
SACL entries for the Group Policy Container objects are configured using the ADSI Edit as follows
1. In ADSI Edit, connect to Default naming context and navigate to DC=domain name, and CN=System.
2.  Right-click CN=Policies, and select Properties.
3. Under the Security tab, click Advanced.
4. Under the Auditing tab, click Add.
5. Now, Add Everyone in the Name field, select This object and all descendant objects in the Applies onto box, and check the checkboxes under Successful for the Create groupPolicyContainer objects and Delete groupPolicyContainer objects
Finally, click OK, and close all the open dialogue boxes.

















In the same way, create another auditing entry. This time, select Everyone in the Name field, select Descendant groupPolicyContainer objects in the Applies onto field, and select the check boxes under Successful for Write all properties, Delete, and Modify permissions.

























Viewing Group Policy change events in Windows Security logs:
After enabling auditing, Group Policy change events are recorded in the Windows Security logs. To view them, search for the relevant IDs using the Event Viewer. Some relevant event IDs are:

5136
A directory service object was modified
5137
A directory service object was created
5138
A directory service object was undeleted
5139
A directory service object was moved
5141
A directory service object was deleted


Article Summary

Group Policy settings play a vital role in determining what domain users can and cannot do in the Active Directory environment. Because of this, administrators must be vigilant when it comes to monitoring changes and modifications to it.
Trying to use native auditing tools to perform regular, detailed audits of Group Policies can be a difficult and lengthy process. Even if you devote the time to it, often the best configurations fail to capture all of the changes that occur. 
This leaves you with two alternatives; using Microsoft’s Advanced Group Policy Management (AGPM) or deploying a specialized Active Directory auditing solution like LepideAuditor Suite, This is one such solution that provides a scalable means to instantly see who, what, where and when changes are made to the Active Directory. It sends real time alerts and provides detailed reports to help with all manner of security, system management and security challenges that your organization may face (without breaking the bank). 

Tuesday, 12 July 2016

Error While Joining Windows server to Domain

Or, Unable to connect an Active Directory Domain Controller while domain joining.

Many of us we face this kind of error’s in our day to day IT Operation Services. There are many reasons for this error like, network Connectivity, Wrong VLAN, Wrong Domain Name, Domain is Down etc. So Today I will take you to one of the reason of this error.


Below is Error Screenshot:

















Reason/Solution: I have investigated and Found one reason, I am able to ping IP address but when I am trying to ping with Domain name” Request Timed Out” error coming and host IP address is configured manually. So I checked and Found IP address details for DNS Server is not mentioned.

























So Now I have given DNS Server IP Address.

























So Domain name is now reachable I can Join that server in domain now. Only Domain Admin user id and password required to join into “Techiessphere.com” Domain.