You can use the following tools (Linux and open source) to troubleshoot network problems:
netstat: Displays information related to open ports on your server. Lets you view listeners and various IP addresses, such as the TCP output state.
iptables: Allows you to change the default ports (8080 and 8443) to the standard ports (80 and 443) for HTTP traffic.
netcat: A networking utility that reads and writes data across network connections, using the TCP/IP protocol. Netcat is useful for checking connectivity with the user store.
ldapsearch: An LDAP search tool useful for Administration Console and Identity Server. For example, you can generate an LDAP search/bind matching what Identity Server sends, to confirm whether an issue is with Identity Server JAR files.
tcpdump: A command line tool for monitoring network traffic. Captures and displays packet headers and matches them against a set of criteria.
LDAP Browser/Editor: Lets you export configuration information to a file, and to confirm that Access Manager objects and attribute values are valid in an AccessManagerContainer. A number of open source versions are available from the Internet.