I would like to increment an ip address by a fixed value.
Precisely this is what I am trying to achieve, I have an ip address say, 192.168.0.3 and I want to increment it by 1 which would result in 192.168.0.4 or even by a fixed value, x so that it will increment my ip address by that number. so, I can have a host like 192.168.0.3+x. 
I just want to know if any modules already exist for this conversion.
I tried socket.inet_aton and then socket.inet_ntoa, but I don't know how to get that working properly. Need some help or advice on that.
Convert the last part of your IP address into a number, add 1 to it, and call ifconfig.

I think the approach of incrementing the last bit will not scale well as we span across networks. –OP

I thought of mentioning that in my original answer, but didn't, for various reasons. These reasons are as follows:

I thought it is unlikely you would need to do this, and could not guess why you'd want to.
Even if you did need to do this, you could just parse the second-to-last number.
This is only valid for those bits where the netmask is 0.
You also have to worry about "special" reserved IP ranges, such as 192.168.etc.etc. Also hex doublets with 0 and possibly ff/255 have special meaning. There are different rules in IPv6.
python increment ipaddress