NetTools is a free AD troubleshooting tool, which provides the ability to troubleshoot, query, report and update Active Directory and other LDAP based directories.  It includes over 80 different features to help with AD troubleshooting, including a powerful and feature rich LDAP client with over 280 predefined LDAP queries.

Some of the features in NetTools

NetTools

NetTools is a single executable that doesn't require any installation, which makes it ideal for field based troubleshooting.

AD Sites

Options include AD Site Browser, overlapping subnets, DC lists, site coverage, IP address allocation

Groups

Group management, view member server local group membership, check to infinite loops, group compare

Information

A couple to NetEnum functions to display user and server information

Schema

The ability to browser the AD Schema and structure, view schema update history, and AD & Exchange schema versions

Network

A number of options to display HTTP headers, Geo IP, Trace Route, Ping, WhoIs, URL and UNC Checkers

Users

User search, troubleshooting for locked accounts, Org structure, and the history of groups changes for a user

Access Control

Options for viewing and troubleshooting Active Directory permissions.

AD Replication

Options to test and view AD Replication, Replication Queues, Replication Cursors, Meta Data

Authentication

View Kerberos tickets, test SPN registrations, Identify token bloat issues, SID History management, Sessions, User Rights and more

Group Policies

GPO Explorer allows you to view the policies, settings, WMI filters, and policy allocations in the domain

LDAP

A feature rich and powerful LDAP Client, LDAP Browser, and compare LDAP Objects, over 280 predefined LDAP Queries

Name Resolution

A number of options to test name resolution, include DcGetDCName, and test common AD TCP ports are open

Trusts

Options to display the details of the trusts that exist in forest

Miscellaneous

A number of additional features, Windows error codes, Base64 and time converters, SID Name resolver and AdminSDProp reporter.