Sunday, April 25, 2021

Uninstall python2.7 ubuntu 20.04

1. Check your current python version using: Mine shows 2.7.8
python --version
2. Remove all python 2.7 artifacts
sudo apt purge -y python2.7-minimal

3. Ubuntu 20.04 comes with python3 installed.  Instead of typing python3 every time, You can create a symlink to make it accessible using python command.

sudo ln -s /usr/bin/python3 /usr/bin/python

4. Check if pip3(python3 package manger) installed or not by typging:


5. If not installed, use below command to install it:

sudo apt-get install python3-pip

Friday, March 4, 2016

Putty network error software caused connection abort

It has been 4 years since I published my post. This is one of the posts that was left as draft in 2012.

Working on remote machines machine can be a pain. Putty can be life saver for windows folks. There are so many useful settings that are hardly touched upon in our daily use. One of them is connection settings.

If you have seen this error 'Network error software caused connection abort putty' every time you went for lunch or tea, then it is time to get rid of it.

It turns out the setting is on the putty not the server side. 

1. Start Putty.
2. “Load” your session.
3. Click on “Connection”.
4. On the section that says “Sending of null packets to keep session active”, put some value there. I changed mine to 300 secs.

"Some network routers and firewalls need to keep track of all connections through them. Usually, these firewalls will assume a connection is dead if no data is transferred in either direction after a certain time interval. This can cause PuTTY sessions to be unexpectedly closed by the firewall if no traffic is seen in the session for some time.

The keepalive option (‘Seconds between keepalives’) allows you to configure PuTTY to send data through the session at regular intervals, in a way that does not disrupt the actual terminal session. If you find your firewall is cutting idle connections off, you can try entering a non-zero value in this field. The value is measured in seconds; so, for example, if your firewall cuts connections off after ten minutes then you might want to enter 300 seconds (5 minutes) in the box." 



Tuesday, August 28, 2012

Receiving 'Access Denied' just after typing the username in Putty

Problem: Getting 'Access Denied' just after typing username in putty.

Information: The above problem occurs because of the failure of GSSAPI authentication.

What is GSSAPI?  
Generic Security Services Application Program Interface(GSSAPI) is a ITEF standard for doing strong encrypted authentication in network based applications. OPENssh uses this API and the underlying kerberos 5 code to provide a alternative means of authentication other than ssh_keys.
The GSSAPI, by itself, does not provide any security. Instead, security service vendors provide GSSAPI implementations usually in the form of libraries installed with their security software.


1. Open Putty.
2. Go to Connection->SSH->Auth->GSSAPI.
3. Uncheck the "Attempt GSSAPI authentication(SSH2-only)" option.
4. Save the session.

Putty: Access Denied Problem

Note: PuTTY 0.62 fixed the bug where failing GSSAPI authentication caused this error message.