SSH slow  login? Disable reverse DNS lookup

when you log into the SSH server, it will do a reverse DNS lookup of the client for security reasons. Thats why it takes a time to login.

vi /etc/ssh/sshd_config (and add the below line:)

UseDNS no

So enjoy SSH

Putty is a free software application for Windows 95,98, XP, & Vista which can be used to make a SSH Connection. You can find the application at Click here

http://the.earth.li/~sgtatham/putty/latest/x86/putty.exe

1. Download it on your pc.
2. Double-click on the putty.exe program to open.
3. Next fill in the appropriate SSH settings for your service:

Next fill in the appropriate SSH settings for your service:

Host Name:

1. • 

     Host name

     • (gs) Grid-Service – s#####.gridserver.com or mt-example.com
     • (dv) Dedicated-Virtual -mt-example.com or xxx.xxx.xxx.xxx
     • (ss) Shared-Server – mt-example.com or xxx.xxx.xxx.xxx
   • Port: 22
     

     port 22

   • Connection Type: SSH
     

     Connection Type

   • Next click Open to start the SSH Connection:
   

   putty open

   Once the SSH Connection is open you should see a terminal prompt saying login as: Please provide your full username:

1. • (gs) Grid-Service – The default should be serveradmin@mt-example.com, however you may also login as username@mt-example.com.

     NOTE:

     Please make sure SSH is enabled for the user. SSH can be enabled from within the (ac) AccountCenter.

   • (dv) Dedicated-Virtual – You may login as the root user, or as a domain’s FTP user which has SSH access enabled
   • Next provide your password. Please note that you will not see any typing such as *** when providing your password. Once you hit enter you should now be connected to your service.

   Common SSH Command

If you want to ssh your vps server or your home computer from your work place (assuming you are using http proxy).You need to use Corkscrew.

corkscrew is a simple tool to tunnel TCP connections through an HTTP proxy supporting the CONNECT method. It reads stdin and writes to stdout during the connection, just like netcat.

It can be used for instance to connect to an SSH server running on a remote 443 port through a strict HTTPS proxy.

Install corkscrew in ubuntu using the following command

sudo aptitude install corkscrew

This will complete the installation.

Configue corkscrew

If your HTTP proxy uses authentication, then you’ll need to tell it about the username and password to use This is where the concept of ‘auth-file’ comes into play. All you have to do is put your username & password, separated by a colon, into a textfile. Once you’ve done this, you just have to tell corkscrew where to find the auth-file. Create a file called .corkscrew-auth in your home directory

$touch .corkscrew-auth

$gedit .corkscrew-auth

and place your username and password in the following format

username:password

Save and exit the file.

Configure ssh For Tunneling

Now we’ll tell ssh what to do when connecting to all or specific hosts. Open up ~/.ssh/config (that’s /home/yourusername/.ssh/config) in your favourite text editor (gedit,nano,vim etc)

$gedit /home/yourusername/.ssh/config

and add the following lines

Host *

ProxyCommand corkscrew proxyhostname proxyport %h %p /home/username/.corkscrew-auth

Save and exit the file

Note: replace proxyhostname and proxyport with the equivalents for your network.

Note: you won’t need to add the last section, ‘/home/username/.corkscrew-auth’, if your HTTP proxy doesn’t use authentication.

What we’ve just told ssh to do is for all hostnames (’Host *’), use the following proxy command to route the connection.If you want more secure connections you can also list of hosts.

Corkscrew Syntax

corkscrew proxy proxyport targethost targetport [ authfile ]

proxy – This is the name of the host running the HTTP proxy.

proxyport – This is the port on which to connect on the proxy.

target – This is the host to reach through the proxy.

targetport – This is the port to connect to on the target host.

Test your SSH connection

ssh serverip

This is a list of Common commands that can be run from root / SSH access.

I. Basic Commands

A. Retrieve Plesk Admin Password

cat /etc/psa/.psa.shadow

B. Change Directory (cd)

cd /path/to/directory/

C. Listing Files/SubFolders (ls)

ls -alh

(files and subfolders listed with perms in human-readable sizes)

D. Checking Processes

ps -a top -c

(process viewer – Ctrl+C to exit)

ps -auxf

(process list)

E. Start/Stop Services

/etc/init.d/<service> start|stop|restart|status

(“/etc/init.d/httpd stop” stops apache)

F. Check Bean Counters (hard and soft limits, failcounts, etc.)

cat /proc/user_beancounters

II. File System Commands (df & du are (dv)-only commands)

A. Check Total Disk Usage

df

(gives physical disk usage report with % used)

B. List Files/Folders +Sizes (du)

du

(lists all filesizes. This will take some time.)

du -sh

(lists all the subfolders/sizes in a dir)

C. Remove/Delete Files (rm /path/to/filename.htm) -DANGER- always verify

rm -vf

(force-deletes file. Dont run unless you know EXACTLY what you’re doing)

rm -vrf

(force deletes folder and all subfolders and files)

To Remove a Directory you can use the following command:

 rmdir  

D. Copy Files (cp)

cp filename.abc /new/path/filename.abc.123

E. Move Files (mv)

mv filename.abc /new/path/filename.abc.123

F. Create Empty File (touch)

touch filename.123

III. File Permissions and Ownership

A. Change Permissions of files (chmod)

chmod 000 filename.abc

(defaults are usually 755 for folders, 644 for files)

B. Change Ownership of files (chmown)

chown user:group filename.abc

(you can see user and group w/ ls -alh)

IV. Checking Log Files (dv)

Log files can tell you a lot about whats going on on a (dv). You can use the command:
‘tail -n 100′ before the logfile name to list the last 100 entries of the logfile.

Here are some of the most common:

A. Main Error Log

/var/log/messages

B. Apache Error Log

/var/log/httpd/error_log

(main)

/home/httpd/vhosts/mt-example.com/statistics/logs/error_log

(per-domain) (May also be: /var/www/vhosts on newer dvs)

C. MySQL Logs

/var/log/MySQLd.log

D. Mail Logs

/usr/local/psa/var/log/maillog

V. Advanced Commands

A. Find. You can do alot with find. for now lets find all files over 10MB.

cd /
find / -type f -size +10000k -exec ls -lh {} \; | awk '{ print $5 ": " $9 }' |sort -n

B. Grep. Another handy tool to get specific information

cat file | grep blah

(only lists the information where the word blah is found)

C. Less/More

less filename.abc 

(displays the content of a file. arrows to scroll, ‘q’ to quit.)

more == same thing basically. You can use the ‘| more’ command to scroll through something page or line at a time.

tail -n 1000 /var/log/httpd/error_log | more

VI. Vi is a basic text editor.

Careful what keys you hit while in vi.

vi /path/to/filename.abc