- Ngoc Huynh
5. PuTTY/Tera Term
When connecting to a variety of different types of equipment, a telnet, SSH or serial client is required; when this is required both the puTTY and Tera Term programs are able to provide these functionalities. The selection of one over the other is strictly a personal preference. Figures 6 and 7 below show both puTTY and Tera Term being used to connect to a host via SSH.
4. Subnet and IP Calculator
One of the most important tools in the belt of a junior network engineer is an IP network calculator. These can be used to unsure a correct IP address selection and with this a correct IP address configuration. While this type of tool is used by senior level network engineers, much of the information obtained from the tool becomes simpler to calculate the longer and more experience you have in the field. Two of the more commonly used free IP calculators include Wildpackets (Bitcricket) Network Calculator and Solarwinds Advanced Subnet Calculator which can be found at the links below.
A very easy test that can be used to both determine the Internet bandwidth available to a specific host and to determine the quality of an Internet connection is the use of the tools available at the speedtest.net and pingtest.net websites. The speedtest.net site provides the ability to determine the amount of bandwidth that is available to a specific host at a specific point in time; this is often a good tool to use when measuring how long it is going to take to upload or download information from a local to remote host. This measurement can also be used to determine whether the connection is offering the amount of bandwidth that was purchased from the Internet provider; keep in mind however that some amount of bandwidth difference is expected between the quoted bandwidth purchased and the measured bandwidth. The pingtest.net website is used to determine the quality of the connection by measuring the ping response times and jitter amounts over a short period of time. This information can be used to determine a likelihood of how well the measured connection will deal with certain types of high demand traffic like Voice over IP (VoIP) or gaming. Figure 9 and 10 below show example output from both of these sites.
In an effort to take advantage of the benefits of both the ping and tracert/traceroute commands, the pathping and mtr utilities were developed. Both of these tools take the functionality and information that can be obtained from these types of tools and provide a more detailed single picture of the path characteristics from a specific host to a specific destination. Figure 11 and 12 below show examples of these two tools and what information they provide.
The last of the tools covered in this article is the route utility. This utility is used to display the current status of the routing table on a host. While the use of the route utility is limited in common situations where the host only has a single IP address with a single gateway, it is vital in other situations where multiple IP address and multiple gateways are available. Figure 13 below shows an example of the route utility being used on a Windows machine.
Source : https://www.pluralsight.com