ssh / scp == slow, http / ftp / etc == ok!

[cantao]

Hi!

After lots of digging in the forums and hours of unsuccesful experiments, there we go:

I work part of the time from home, using an ADSL line to connect to 3 different servers. The connection is made through ssh. My servers are Gentoo, and the other two are Suse and Mandrake.

I can make downloads, watch movies, etc, etc, etc at a very reasonable speedy (about 75 kb/s). But when using ssh the connection is choppy, and scp gives me about 14 kb/s. Eventually 25 kb/s, but most of the time less than 20 kb/s. I am discarding:

1. IPV6 problems
2. ISP problems (checked)
3. Hardware
4. Hacked systems

The interest thing is that I'm having this bad performance since the last week.

Any hints?

Thanks a lot, Cantão!

[ekutay]

[cantao]

Hi Ekutay!

Hum... I don't know exactly what ICMP packages have to do with that (networks are not my speciality ), but until last week I could do scp copies around 65 kb/s, very close to usual http / ftp downloads.

Thanks a lot, Cantão!

[ekutay]

When I have network trouble, I usually run tcpdump and look for ICMP packages. Noroutetohost or noroutetonetwork, network congestion or timeouts are announced with ICMP.

[cantao]

Hi Ekutay!

Yes, I tried both tcpdump and ethereal, just didn't know what to look for . Concerning your first reply, I tried again at night. The transfer rate with scp raised to 45 kb/s average, with 50 kb/s peak. Of course late in the night network usage drops, but interestingly enough, I get more or less the same download (http / ftp) speeds as during the day.

Quite strange

Anyway, thanks again for your help! Gonna try the tcpdump stuff with ICMP.

Cheers, Cantão!