Posts Tagged “tcp”

Xplico is a NFAT or Network Forensics Analysis Tool that is designed to either capture traffic in real time sessions or to provide an interface to upload PCAP (Packet Capture Data) files for analysis. The current version in Backtrack Linux 5 release 3 is 0.7 however the latest Xplico version is Xplico 1.0.1. I believe there are some dependencies required in the later versions of Xplico so I will write an updated article once Backtrack 6 comes up and the latest version of Xplico can easily be installed.

Read the rest of this entry »

DeliciousStumbleUponDiggTwitterFacebookRedditLinkedInEmail
Tags: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,

Comments No Comments »

A company asked me to analyze some of their network traffic to verify some of the projects they are working on to cut costs won’t impact their business. One of the projects includes removing a 100 Mbps fiber connection to their colocation and replacing it with a cable modem that is asynchronous with 50 Mbps download and 5 Mbps upload. Unfortunately they do not have any solid historical network data capture software such as Cacti so before setting up such a service I had to provide initial data via what was available. One of the tools I was able to use was the dashboard data that lives in memory on their FortiGate 200A. Below is information on where to find this information in the FortiGate 200A dashboard.

Read the rest of this entry »

DeliciousStumbleUponDiggTwitterFacebookRedditLinkedInEmail
Tags: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,

Comments No Comments »

While doing some testing of Oracle on a Windows 7 computer I stopped the TNS Listener service also known as OracleOraDb11g_home1TNSListener. The problem is when I attempted to restart the service it would not start. While testing various other things I had made numerous changes so I started looking into what might cause the issue and was pretty confident that the $ORACLE_HOME variable I set within the Windows Environment Variables was probably the culprit. Below I describe more details about the error as well as how I resolved the TNS Listener not being able to start.

Read the rest of this entry »

DeliciousStumbleUponDiggTwitterFacebookRedditLinkedInEmail
Tags: , , , , , , , , , , , , ,

Comments 2 Comments »

It had been awhile since I have installed NRPE or Nagios Remote Plugin Executor running through xinetd so once I thought I had everything configured I attempted to restart xinetd but NRPE was not working properly. Below I describe the error in more detail along with how I resolved the issue. In the below example the server was running CentOS Linux.

Read the rest of this entry »

DeliciousStumbleUponDiggTwitterFacebookRedditLinkedInEmail
Tags: , , , , , , , , , , , , ,

Comments No Comments »

The next tool up for review in the information gathering section is tcptraceroute. tcptraceroute is a traceroute implementation using TCP packets. The more traditional traceroute sends out either UDP or ICMP ECHO packets with a TTL of one, and increments the TTL until the destination has been reached. By printing the gateways that generate ICMP time exceeded messages along the way, it is able to determine the path packets are taking to reach the destination. The problem is that with the widespread use of firewalls on the modern Internet, many of the packets that traceroute sends out end up being filtered, making it impossible to completely trace the path to the destination. However, in many cases, these firewalls will permit inbound TCP packets to specific ports that hosts sitting behind the firewall are listening for connections on. By sending out TCP SYN packets instead of UDP or ICMP ECHO packets, tcptraceroute is able to bypass the most common firewall filters.

Read the rest of this entry »

DeliciousStumbleUponDiggTwitterFacebookRedditLinkedInEmail
Tags: , , , , , ,

Comments No Comments »