Pinging etc

[moribundman]

I just found out by accident how to "ping" on my Mac. The feature is found in the Network Utility and provides, among some other features, Lookup, Traceroute, Whois, Finger, and Port Scan.


Question 1: When would I want to "ping?" Is it only used to see if another IP address is available for data exchange?

Question 2: What's the purpose of "Finger?" Who do I want to finger and why?

Question 3: What's the "Port Scan" good for?

 

[moribundman]

Oh, never mind. I just found some answers. What a thrill. I think I'm f a l l i n g a s l e e p . . . zzzzZZZZzzzZZZZzzzzz.......

 

[oilboy123]

I have done it in the past. But I forgot how to it again.

Nothing like learning something then having to relearn it again......

My first thought was a pinging vehicle?

 

[moribundman]

I was thinking submarines! Up periscope!

 

[PandaBear]

1. check if the connection/route is working and how fast/reliable is it.

2. what is finger?

3. check if something is there that you can connect to. Either for security purposes or connection/route availability purposes.



Off topic:

If you have a few computers and you want to let income connection to each of them, you can set "port forwarding" in the router and dedicate a set of port for each computer. Convenient if you want to share a network with a few friends/family member that wants to have incoming traffic on their own machine.

When I was using DSLExtreme, they are so generous that they gave me 5 IP, no more messing with router.

 

[moribundman]

Originally Posted By: PandaBear
2. what is finger?


I only have one or several wise answers, plus visual aids, none of which you will like much...

Let's go with this:
Quote:
Finger
The Finger (command-line program finger) tool of the Network Utility application gives you the ability to query the finger server of a host. This server, if enabled, will provide information regarding who a user is (full name, and so on), and when the user was most recently logged in. It is generally considered to be a minor security risk to run the finger server, because it lets crackers know whether it's safe to break into a system. But, if you know of a machine that has the service enabled, you can use this tool to access it. Figure 9.32 shows the results of using the finger tool to finger [email protected]. Notice that the server returns information about all known users with ray in their names. Different finger servers will return different information about users. This one is rather sparse, leaving out most of the users' personal information, but still indicates whether the users are logged in or not.

 

[javacontour]

Let's see if I can answer even though you said you found answers.

Originally Posted By: moribundman
I just found out by accident how to "ping" on my Mac. The feature is found in the Network Utility and provides, among some other features, Lookup, Traceroute, Whois, Finger, and Port Scan.


Question 1: When would I want to "ping?" Is it only used to see if another IP address is available for data exchange?


In the TCP/IP model, the IP layer is responsible for routing datagrams from one node to another, ping used ICMP messages to verify that you can reach the node you are pinging. So if you are having networking difficulties, you can ping various components in your network to see if you can reach them. I.E. can you ping other computers in your home, or your default router, etc.
Originally Posted By: moribundman


Question 2: What's the purpose of "Finger?" Who do I want to finger and why?

Old school unix program from the early days of BSD, if I recall correctly. Finger would give information from your .plan file if it was enabled. I've seldom seen it used in the past 10 years or so. But back in the '80s when I was in school, it was how you learned what others were doing.
Originally Posted By: moribundman


Question 3: What's the "Port Scan" good for?


Hackers and those who are looking to secure computers both use port scanners. Hackers to see what services you may be running and then to try ID the O/S you are running, target you with exploits, etc. The good guys use it to locate potential security risks and disable vulnerable services such as telnet, rlogin, ftp, etc.

 

[javacontour]

Wow, I remembers regarding finger. That seems like 100 years ago

http://www.faqs.org/rfcs/rfc1288.html

Notice the original RFC for finger dates back to 1977

http://www.faqs.org/rfcs/rfc742.html

 

[javacontour]

RFCs are often fun reads Notice that RFC1288 contains the following:

Quote:

2.5.5. Vending machines

Vending machines SHOULD respond to a {C} request with a list of all items currently available for purchase and possible consumption. Vending machines SHOULD respond to a {U}{C} request with a detailed count or list of the particular product or product slot. Vending machines should NEVER NEVER EVER eat money.



BTW, RFC stands for Request for Comment, this is the mechanism many/most Internet related protocols were announced, discussed, etc.

 

[uc50ic4more]

Originally Posted By: moribundman
Question 1: When would I want to "ping?" Is it only used to see if another IP address is available for data exchange?


Often I will try to log into a friend/ family/ neighbor's system to perform updates or troubleshoot. If I cannot connect, the first thing I try to do is ping the client machine to make sure that it is still breathing.

Pinging a site that you darn well know ought to be up and running, like Yahoo, will confirm for you that you have network connectivity, too.

Pinging can also report to you how much latency is involved in a connection.

Basically, though, it's just:
"Hey, you there?"
"Yup."

Originally Posted By: moribundman
Question 2: What's the purpose of "Finger?" Who do I want to finger and why?

I've only ever know finger to give rudimentary information about a user.

Originally Posted By: moribundman
Question 3: What's the "Port Scan" good for?


The best analogy for a port scan is when a hacker scans your system for an open port through which he or she wishes to gain access to your computer: It is like a burglar jiggling a door knob, then trying to open a window, then looking under the welcome mat for a spare key, etc.; they're just running through a list of potential vulnerabilities.

It's nice to visit a site that will conduct a port scan on your system so you know if you have any open that needn't be. A web server, for example, has to at least have port 80 open, as that is the port through which web sites are served. Email servers, SSL connections, FTP connections, etc. all require different ports, so computers that intend to use (as a server) these function needs those ports to be open.

For me to be able to access my client's machine, then, I have to have port 22 open on their machines so I can issue commands to them, and port 5900 open on their machines so I can take control of their screen. Their machines are running a SSH server on port 22 and a VNC server on port 5900.

 

[wavinwayne]

Quote:
Finger...It is generally considered to be a minor security risk to run the finger server, because it lets crackers know whether it's safe to break into a system...


Hey!!!

 

[moribundman]

Thanks guys!

I believe I came across "pinging" when I set up my wifi internet tablet. I ran into some problem connection to my Mac and I remember someone telling me to "ping." I managed without pinging, though.