How do I do a DNS lookup?

How do I find my DNS server Cisco Packet Tracer?

For any given system running Cisco Packet Tracer, there is a DNS server running on the system itself. However, it is not the primary DNS server on your network and there is no configuration on the system to point DNS requests to this server. You should use the DNS server on the main router of your network, known as the default DNS server.

The default DNS server is used in order to reduce latency on your network. By setting the DNS server on the main router, you are directing all DNS requests from the system to the server on your main router. The server on your main router can provide faster DNS response times than an Internet DNS server, due to being closer to your system and having lower traffic.

You will need to verify that the DNS server on the main router is correct before you begin setting up the system. If you have multiple routers in your network, you will need to verify the DNS server on each system in order to ensure they are all being pointed to the same default DNS server.

Open Service Console and look for the DNS Server setting under Network Services. Verify that the DNS Server field shows either local or secondary DNS server. If the setting is blank, it means that the system does not have a DNS server configured.

If you see a value listed under the DNS Server setting, make sure it is correct. In the case of a domain name, you will need to enter a domain name, then enter an IP address and port number.

For example, the IP address of my computer is 10.2.12.11 and the port is 80, I would enter 10.11:80. You will use the first DNS server returned by the server you are using.

Set the DNS Name Server to the DNS server that you just verified. You can also setup a local DNS server to handle local (on-site) names instead of pointing them to the public DNS servers. This could be useful if the site has a network name that needs to be available in the local network for other applications to use. This includes IP addressing information, which is the same information used for public DNS, but on a local network instead of being accessible from the Internet.

To set up a local DNS server, use the same steps as the DNS server configuration, with a few exceptions. Type the hostname of the DNS server in the Host Name field.

How do I do a DNS lookup?

As the name implies, DNS is used to find out how a name such as 'www.yieldvisits.com' maps into an IP address. It sounds trivial but it's not. The whole internet is run through a system of names and IP addresses and this information must be stored in computers (called servers) so that it can be resolved. So let's start at the top.

The Domain Name System. If you try a web request to the name www.com or some other domain (it could be cnn.com, amazon.uk etc.) you should actually receive some type of HTTP response. This tells you that the domain, and the name of any page you requested, has been mapped into some type of IP address on a computer somewhere on the net.

This means that the Domain Name System, otherwise known as DNS, does more than just map a name to an IP address, it also maps domain names top-level domain names and country code domain names, as well as to names within some sub-domains of a domain. If you do a web request from your PC to www.com this will almost certainly take you to a web site hosted on some computer somewhere in the world called google. That's because the DNS has been told where to send the request to based on the name and the computer running that name has been told what that website's top-level domain is.

You don't think about DNS too much, but there's quite a lot of technical jargon involved. To avoid all that we'll look at some fairly simple scenarios. One very common one is for someone to visit a site such as our yieldvisits. Let's say that person came via their web browser or by clicking on a link in an email. They'd now need to connect to that host somewhere to get some type of data. That's what a DNS lookup is - finding out where that computer is. It's a bit like trying to find someone's number in a phone book or looking up a business's telephone number in the telephone directory: you start with an initial search point (an address to check) and then you make phone calls, asking someone what house number, street, number, town, postcode, etc. It is.

We often put a "www.