And.....I will add....obviously you will not be able to decode the actual
traffic of the SCP'ed connection.
But, you need to look for re-transmits, failed TCP connections, collisions,
CRC errors, or anything that your
traffic analyzer will show you.
Start eliminating the layers of the OSI model to ensure it isn't an actual
network related problem. I'm not sure of your
level of expertise in this area, but it isn't uncommon to have a duplex
mismatch on a network, which will cause MASSIVE
collisions is you are on a switch. If you are on a hub, then it can be
similar depending on what type of nic you are using.
Well enough said.
> I can only theorize on the problems. But, it actually sounds like some of
> this may be coincidental.
> It may be that you actually have network problems causing what you see.
> SCP is, of course, encrypting the information across the wire. The higher
> the encryption, the more data flowing.
> If there are layer 1/2 problems on your network, such as collisions, or an
> invalid duplex setting, then you are exponentially (well, maybe not that
> increasing the chances of problems happening when using SCP. Meaning,
> information that is NOT encrypted would have a less likely chance of havin
> the collision or problem as it would take less data to send. BUT that is a
> VERY vague statement as it depends on the length of the cable, size of the
> frame (assuming Ethernet), etc. etc.
> Of course, the reason I say it may be coincidence, is that you are having
> the problem with FTP as well. And FTP should be plain, and simple.
> To troubleshoot, I would definitely get a packet analyzer out and watch
> traffic. Something like Ethereal, tcpdump, or snoop (assuming you are
> the unices) and of course, Ethereal will work on the WIN32 platform.
> You will need to look for CRC errors. I'd bet a dollar that is what is
> on ;-)
> > I've got two strange problemsm after installing OpenSSH 3.02.p1.
> > I have two machines running RH 6.2. Both have running the same version
> > of OpenSSH, server has a sshd deamon running, started through the
> > inetd.
> > First, it appears that ftp connection between my machines on the local
> > network became **way** too slow after installing ssh. It's not like it
> > fails, but it takes much longer to get an ftp prompt. Why it might
> > happen and how I can trobubleshoot it?
> > Second problem started very recently after I've installed sybase
> > 11.9.2 on my server with the corresponding user. Before scp worked
> > fine and now problems were seen. Now when I try to copy files between
> > machines using scp, it copies them and then hangs and continue to send
> > the same file over and over resulting in a very big target file. Does
> > anyone knows what could I changed in ssh configuration that caused
> > such a problem?
> > Thanks,
> > Sergey Malov