Tag Archives: connection

mosh: I see the what, the where, the how … but the why?

I don’t ever recall hearing a discouraging word about ssh, which easily ranks among my top three coolest tools ever.

I wouldn’t say it’s without faults though, and I assume that’s the reason why there’s mosh.

I’ve had hanging connections in ssh, particularly if I shut down a machine while still connected. I don’t know if mosh would help with that or not, but judging by its description, it might be a better tool if ssh is causing problems.

But I don’t know how to show that, in a screenshot.

2014-01-15-lv-r1fz6-mosh

I guess if you have a poor connection and you’ve seen ssh misbehave, mosh might be a better application for remote connections.

As it is, I’m just connecting between two machines on my desktop here. And barring a lighting strike, massive solar flare or a meteor crashing through the roof, interference is unlikely.

So all the pieces are obvious and I can figure out how to work it. I just … don’t … know … why. … 😦

iperf: Internet performance, as luck would have it

iperf is new to me, and it appears there is an iperf3 in the works, so as usual, it appears I am late to the party.

iperf allows speed testing for network lines, which might be useful to you in some situations, like when your landlord is deliberately choking access. 👿

On an unrestricted line though, here’s what it looks like.

2013-12-04-lv-r1fz6-iperf

iperf is pretty easy to handle, but you’ll need to connect to a server that’s prepared for it. You can’t just aim iperf at Google and hope for a line speed measurement. (I know, I tried. 🙄 )

However, there are some public iperf servers out there that you can test your strength against. The one you see in that gif was on a list from the Wikipedia page. There are others there if eltel.net is inconvenient for you.

In-house, I imagine this would have more use, since it does offer some line quality options too.

Perhaps you can find out where that annoying whine comes from, when you transfer files between computers. Just kidding. 😉

echoping: Another gray area

I must be displaying my ignorance on a daily basis with this blog. Reason being, I run into a large amount of software that I lack the expertise to use.

And then I broadcast it to the world. 🙄

2013-10-18-lv-r1fz6-echoping

That’s echoping, and boy oh boy, did I ever struggle with this one. I first tried it out months and months ago, and got nothing out of it.

But unlike some other software I’ve seen lately, I had no reason to believe it was somehow broken or miscompiled.

Judging by the endless “connection refused” messages, it actually was actually reaching out and connecting to the addresses I gave it — for example, my building router and this machine. From that I could tell that it was at least working.

A closer look at the man page gave me an idea of what would actually work … which you can see above.

echoping might be more useful if you’re worried about server performance, instead of just connections. Try the -n flag for a series of tests, and an analysis of the results.

Of course, it will help if you get it running right to start with. 😉

Sheesh. You’d think after years of digging through software and fiddling with oddball programs, I’d have a better grasp of some of these things, no?

Apparently, no. 😦

doscan: Oddly enough, I get nothing

In this business, if a program gives me nothing at all as its output, it means one of two things.

2013-10-16-4dkln41-doscan

First, and the less likely of the two, it just doesn’t work. I’ve run into more than one of those in the D section; I’ll list them out for you in a day or two.

Second, and probably the problem in 90 percent of cases, I’m using it wrong, and being a dunderhead.

That’s probably what’s happening in the screenshot above. That’s the Debian version of doscan, which by all rights should list machines on my local network listening for a TCP connection.

I used the address above as a sort of generic network that I don’t mind sharing on the Internet, and of course as you can see, nothing comes about of it. Not even an error message.

But it’s the same for my actual network address. And if I try a wider, building-wide network? Nothing. What’s worse, the two commands there are straight from the man page as examples.

And yet, I see nothing as output. I assume that a null response yields nothing, but I also wonder if maybe something in doscan’s guts has gone sour, and all it will ever report is a blank line. 😦

It could be the case. Like I said, that was the Debian version. There is no version in Arch or AUR, and my attempts to build it from scratch resulted in make errors.

That does make me a little suspicious, not just because the last update listed at the home page was in 2003. Like I’ve said, 10 years is not a huge issue for Linux software, but it does make me look askance.

I open this one to the general public. If you can get doscan working and displaying some sort of output, please share. I am left wondering why, oddly, I get nothing. 😐