During my one-and-a-half-month stay at home I started using a local broadband connection for internet. But all of a sudden to my utter surprise, I saw that the default ethernet connection (named eth0) had vanished, without which, as evident, I won't be able to access internet on returning to college, because, the current broadband settings were manual and I couldn't think of automating everything, as this would interfere with my ease at home.
My fear quite turned true, back at college. A few initial attempts did fail, but the solution was simpler than thought.
1. On the top-panel, right-click the internet connection icon, and select Edit Connections....
2. Click Add.
3. Under the tab IPv4 Settings, select 'Method' Automatic (DHCP) and under IPv6 Settings, select 'Method' Ignore.
Note: For most users, method Automatic would have worked.
4. Connect automatically and Available to all users are optional. Give a suitable name (for example eth0).
5. Click Apply.
These automatic settings, unlike the manual ones, can be used inside any LAN network, as it automatically detects the addresses. If you know the Netmask, Gateway and IP addresses, then you can manually configure, but I prefer automatic settings for LAN.