Speed up scp file transfer

Description :
Many times it is required to transfer files across machines on the same network , all machinesbeing on the same network and behind proxy its useless to transfer them with an encryptionwhich is more CPU ntensive than other and also slower than others.There can be other methods to transfer files of course , ftp , sftp , rsync, but this document is justabout scp command.

Objective :
To find out what is the faster cypher to define in scp command to transfer files on an internallocal network.

Environment :
Two Linux machines, with same openssh versions.Connected on a 100 Mbps LAN . Both being idle nothing is running on them at the moment .Before each test files will be cached on the file system buffer , so the tests are not affected withcache.
Tests :
Copy 1000 small, medium , large files across the network using different cyphers in scp command and measure their real time.

These are the file sizes :
Small : 10K
Medium: 100K
Large:1000K

Overall arcfour performed better than any other cypher used. It is safe to say that arcfour
can beused to transfer files using scp on an internal network.

You can define which cypher to use by -c option of scp.

scp -c arcfour filename.txt host:/path/filename

/etc/ssh/ssh_config
Ciphers arcfour128,arcfour256,arcfour,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc