What we can do in a Terminal window using unix tools can also be done in Network Utility. When you open Network Utility, you will see 9 different tabs corresponding to 9 Network Utility utilities. Here we will learn what we can do with these 9 utilities.
1. Info
The first tab of Netwok Utility, Info, gives us some general information about the network we are connecting to. The Network Interface drop-down menu shows all the different methods that the Mac can use to connect to the network. Typically, these methods include: Ethernet, Wireless and Firewire.
Next is information about Hardware Address and IP Address . In case the network interface is connected, we will only have one IP address, otherwise it will display as Unknown (unrecognized). Hardware Address , or Mac Address , can be used to identify a system that is unique (although we can change this address).
A very useful Mac address is when installing a Wifi Router. We can install for most routers that only allow specific connected Mac addresses, which means that unassigned users will not be able to log in to your Wifi network and connect to the Internet.
2. Netstat
Netstat is a useful network debugging tool for administrators, but it is not appreciated by ordinary users. If you choose the Display routing table information option and then click Netstat , we will see a list of all computers on the network.
If you choose the option Display the state of all current socket connections and then click Netstat we will see a list of network connections of the system. For example, the first items in the list will correspond to the visited Web pages. If you enter the addresses as Foreign Address in Safari, it is possible that the site will display.
3. AppleTalk
The AppleTalk tab is quite similar to the Netstat tab, but only for an Apple protocol called AppleTalk. This protocol has been used quite commonly in the early stages of Mac, but now it has been abandoned and no longer supported in Snow Leopard (in Snow Leopard this tab no longer appears).
4. Ping
Ping is a tool used to check if the Internet address is working. When pinging an address, we sent a small amount of data then it was sent back.
We can use this tool to check if a website has crashed if it cannot be downloaded in Safari. Or in case the network connection shows signs of collapsing, we can ping pages that never crash, like google.com, bbc.co.uk, . to check if there is a problem with the network.
5. Lookup
Lookup tool allows us to collect information about a Web site or IP address. The drop-down menu of the Select the information to lookup section allows us to select a number of different types of information. For example, when we perform a server name lookup on macosxtips.co.uk we will be notified that this page is hosted by Dreamhost server, and when we look up MX Record (or Mail Exchange Record), we will be notified that email is handled by Google.
6. Traceroute
When we enter an address then click Trace , Traceroute will show the way that data is sent between the client and server. This tool allows us to check every server for which data is transferred.
We can use Traceroute to overcome some network problems by detecting data blocking points. In addition, we can use this tool when downloading a file with many different download links to choose the fastest link. Just enter those links into the Traceroute, so we can know which links are the fastest.
7. Whois
The Whois database gives us information about Internet addresses and who has registered them. The default Whois server, whois.internic.net, works fairly well with most addresses, but notice we need to enter the correct domain name. For addresses .co.uk using whois server is whois.nic.uk . We will get information such as the signer, the address, the time of registration, and the expiration date.
8. Finger
Developed in 1971, Finger is one of the first pieces of status updates that are currently being used by many social networking sites, such as Facebook, Twitter, etc. This tool is almost no longer available to users. use, but with this tool we can check if our friends are available online, and can post .plan files to profiles like posting to blogs.
One of the most effective ways to use the Finger is to enter your user name or the name of another user on the Mac system, when the Finger button is pressed we will be notified that the user is currently logged in. No, and the amount of time posted before the user has made it.
9. Port Scan
Port Scan, the last tab in Network Utility, has the function of checking which ports are open at a certain address. These network ports are a virtual version of the ports on the system, and each port is used for a different network traffic. For example, port 80 is used for Web sites.
We can use Port Scan to check individual computers by entering the form [computer name] .local . When we click Scan we will see this name appear in the Sharing area of System Preferences .
Tools like iTunes Sharing, Instant Messaging, BitTorrent, AFP and SMB Sharing all use different ports. If you see that one of these ports doesn't work, it may be because the firewall system has blocked it, so we can change the configuration to reopen it.
We can use Port Scan to check individual computers by entering the form [computer name] .local . When we click Scan we will see this name appear in the Sharing area of System Preferences .
Tools like iTunes Sharing, Instant Messaging, BitTorrent, AFP and SMB Sharing all use different ports. If you see that one of these ports doesn't work, it may be because the firewall system has blocked it, so we can change the configuration to reopen it.
Just run Port Scan with the Sharing application or turn off and turn it on to check the ports that appear. We can then install the firewall to open this port and allow network traffic to pass through it. Note that the built-in firewall system in Mac OS X operates on an application platform rather than a port platform to simplify tasks for users.