Speeding up SSH SCP connections

Speeding up SCP copy operations

So you're quickly copying a ~12GB MKV file from your download server to your archive server and are only getting a paltry 25MB/s.... obviously it isn't the network or disk as you've tested the dual gig connection at around 80-90MB/s via samba. You can't be arsed using rsync so you use scp to copy it but it's pretty damn slow.

file.mkv  12% 1893MB  22.0MB/s   10:23 ETA

Sound familiar? Well, you'll need to change the encryption options and turn off compression.

You can either do this on the command line (scp -c arcfour). Arcfour is plain RC4 with a 128-bit key (RFC4253).

or your could change to ~./ssh/config file to something line this:

Host hal
        Compression no
        Ciphers arcfour

After these changes you should be getting around double to triple the SCP copy speed

      100%   15GB  50.3MB/s   05:10

Please note this is for internal connections only. I wouldn't recommend this for external connections.

Enabling SSH on a brocade ADX1000 series load balancer

Despite what it says on http://www.brocade.com/support/Product_Manuals/ServerIron_AdminGuide/manage.2.3.html#29293 I had to do it a different way.

Getting to work is actually a lot harder.

First clear off any keys that were in there:

ServerIronADX(config)# crypto key generate rsa

ServerIronADX(config)# write mem

ServerIronADX(config)# crypto key zeroize rsa

ServerIronADX(config)# crypto key zeroize dsa

Now create a random seed

 ServerIronADX(config)# crypto random-number-seed generate

Create the DSA keys

ServerIronADX(config)# crypto key generate dsa

Also set auth to check local accounts first with

ServerIronADX(config)#  aaa authentication login default local

then after checking it works

ServerIronADX(config)#  no telnet server

Enabling Agent Forwarding on Mac OS X (and it's still not working)

Ok, so you've SSHd onto your favourite box, but when you try to connect to another linux server, it asks you for a password.
Huh? you say? It's ssupposed to use my private key!

First check if it's accessing the correct directory
#ssh server -l phil -v 
if the last few lines contain /root/.ssh/id_rsa or something similar

make sure those files exist

Also make sure in /etc/ssh_config
these lines exist

Host *
ForwardAgentYes

If this is still not working

on your mac run
#ssh-add

tada!