Archive for the ‘Computer Networking Tools’ Category
MTR (My traceroute; originally Matt’s traceroute) is a free and open source Linux utility that combines the functionality of both traceroute and ping, and as such is a more sophisticated tool (go here to brush up on your knowledge of these two commands). Not only does MTR reveal each hop between your host and a destination (as traceroute does), but it also sends a sequence of ICMP ECHO requests to each hop to determine the quality of the link (like ping). Simultaneously it displays running statistics about each hop. MTR supports both IPv4 and IPv6.
The simple command syntax for MTR is mtr [options] [target]. The range of options for MTR is described below.
The free Ping Tool from Colasoft is a graphical interface for the ping command. The Ping Tool issues continuous ping requests to the target you specify and then creates charts to graphically depict the response times.
At the time of writing the latest version available was 1.1, Build 265 (released in Feb. 2008). The autoupdate function (Help -> Check for Latest Version) found no newer version to download.
Several of the programs described in this blog (such as SamSpade, SuperScan, and LanSpy) are basically graphical front ends for issuing common network query and diagnostic commands, and displaying their results. The aforementioned tools make it easy to use commands like ping, traceroute, nslookup, whois and others, and the results of these commands are presented in easy-to-read formats.
Two popular graphical interfaces for the netstat command are TCPEye and Currports. To properly utilize these tools, you need to first understand the function of the netstat command. Netstat displays protocol statistics and the current TCP/IP connections of the computer on which it was invoked.
Network administrators and tech support professionals have done it hundreds of times: configuring Windows IP settings. When a client machine needs static IP parameters, we follow the familiar path of Control Panel -> Network and Sharing Center -> Change Adapter Settings -> right-click the network interface, choose Properties -> highlight ‘Internet Protocol Version 4 (TCP/IPv4)’ -> select ‘Use the following IP address’ and ‘Use the following DNS server addresses’. For Windows XP the slightly different procedure is Control Panel -> Network Connections -> right-click the network interface, choose Properties -> highlight ‘Internet Protocol (TCP/IP)’ -> select ‘Use the following IP address’ and ‘Use the following DNS server addresses’. To revert back to DHCP functionality, you would select ‘Obtain an IP address automatically’ and ‘Obtain DNS server address automatically’.
This process and the ‘Internet Protocol Version 4 (TCP/IPv4)’ graphical interface (below) are cumbersome and time-consuming.
For those who frequently change their network configuration (such as information security professionals conducting vulnerability assessments and penetration tests, or individuals who work in multiple locations), there are several utilities available that simplify the process. Rather than go through the steps above to change IP settings, you can just launch a program, enter in your desired settings, and click ‘Save’ or its equivalent. Instead of describing them individually in multiple blog posts, I will present them all here in no particular order.
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PingPlotter Freeware from Nessoft is a scaled down, free version of Nessoft’s two other PingPlotter commercial products, PingPlotter Standard and PingPlotter Pro. PingPlotter Freeware is essentially a graphical user interface (GUI) for the tracert/traceroute command line utility. It runs on all versions of Windows from Windows 98 to Windows 7 and 2008.
PingPlotter Freeware v1.30 was released on July 12th, 2010 and was the latest version available at the time of this writing.
Tera Term has been one of the industry’s mainstay terminal emulators. Network device administrators in particular have used Tera Term because it supports both telnet/SSH and serial connections.
There are presently two versions of Tera Term available: version 3.13 from Ayera Technologies and version 4.7 from LogMeTT. This schism occurred as a result of Tera Term’s disjointed development process.