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Someone (gregc?) mentioned a command to find out whether or not the internet connection is going. Seems to me it was "ping something." What was the command again?
18 responses total.
Ping seems to be unavailable to anyone except staff. But something (I presume the host we're immediately connected to) is being pinged every 6 minutes, and the log of the results of those attempts is in /usr/stats/PingLog. A simple way of seeing the results of the last ping is (from a Unix shell prompt): tail -1 /usr/stats/PingLog From a bbs prompt put ! at the beginning. If you want to see more lines, replace the -1 with -5 or whatever, or leave it out entirely to get 10 lines. If it says "is alive" then the net link was up at the specified time; otherwise it should say "no answer" and the link is down.
I think anybody can run ping. It's in a directory that's not
on people's standard path, so you need to type the full pathname:
/usr/etc/ping.
You use ping to find out if another machine on the internet is up, e.g.
/usr/etc/ping uwasa.fi
would normally print "uwasa.fi is alive".
Ping won't work at all if Grex's internet connection is down.
Regarding ping, the internet connection and news: End of article 1215 (of 1228) -- what next? [^Nnpq] > >** here I had asked for the next article (spacebar). Rn was picking >stuff off the "overview file" and I believe this was the >specific location where the overview file was "changing pages," >if that makes a difference. ** > >Unexpected close of server socket. >grex% date >Wed Jan 26 13:37:28 EST 1994 >grex% tail -2 /usr/stats/PingLog >Wed Jan 26 13:26:01 EST 1994 152.160.1.17 is alive >Wed Jan 26 13:32:00 EST 1994 152.160.1.17 is alive >grex%tail -4 /usr/stats/PingLog >Wed Jan 26 13:26:01 EST 1994 152.160.1.17 is alive >Wed Jan 26 13:32:00 EST 1994 152.160.1.17 is alive >Wed Jan 26 13:38:00 EST 1994 152.160.1.17 is alive >Wed Jan 26 13:44:00 EST 1994 152.160.1.17 is alive > >I'm confused. > >
did you try /etc/ping 152.160.1.17, tsty when there was that problem? tailing the pinglog only shows the last time ping checked, not if it is up at that very second.
Part of the question is about the server socket. Who's server socker shut down, Grex or iunet? Does the ping log show that between 13:32 and 13:38 the connection died and then was born again?
Info 101 likned to Internet 23.
re the question, did the connection die and resurrect itself within the six minutes?
No. Our link stayed has been up without interruption. I think what you saw was probably a failure somewhere else, beyond the immediate connection. I saw something similar last night, but it's working now.
What is a server socket and how are/is they/it opened anc closed, either on purpose or, "unexpectedly?" How is the server socket related to the link.. without interruption?
A good deal of internet communication is handled by creating data
sockets (they're a sort of buffer, much like a pipe, that is a bit more
difficult to program). If your socket isn't functioning, then you can't
communicate, as that buffer isn't there. If this doesn't make sense, let
me know - it's hard to explain in Real English.
From the program's point of view, opening a socket is kind of like opening a file - except that instead of allowing you to read & write to a disk, it provides the means to read or write information to another process (often on another machine). This process is commonly a server, a process that's running all the time to allow you to do something in this very manner. For example, in order to telnet somewhere, there needs to be a telnet daemon running on that site, which is what you're actually talking to; that process handles logging you in on that site and everything else - telnet on your site passes what you type on to the daemon, which passes it to other programs on the remote site. So if the communication channel (socket) is closed unexpectedly by something on either end, you're stuck.
Think of the News server at condor as an all night Domino's pizza, and the socket as your phone, most of the time you can call up and make a conection adn do useful business, and sometimes somebody firebombs the joint and your phone just rings and rings and rings......
...yeah, but the damage to the news server at condor tends to be easier to repair than the damage the average firebomb would cause at the average Domino's....
Is a "socket" like a small sock in which things are stored, like at Xmas time, or is it like a jack into which things are plugged, like a wall socket, or is it like 'socket to me, Greg'?
The second of those 3 - but instead of a power socket think of an old- fashioned telephone switchboard.
Yeah, exactly. The word "socket" was used because of it's similarity to a wall-socket and that by opening a socket you are connecting to the network beyond your wall. The socket interface is an abstraction that allows programmers to use a an interface they are already familiar with(file I/O), to access network resources.
A few minutes ago, iunet was down, rn failed and THEN closed my modem connection.. that's a fine how-do-you-do!
Does that have anything to do with the problems UM has been having today? (Servers down all over the place...)
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