Today I took down networking on one of our production host machines. It’s not a machine local to us, so we were fortunate enough to have a secondary network setup to access the server from another server of ours.
After much troubleshooting as to what wrong, I found the tricky answer. Here’s what I did:
I had commented out a line on my practice machine, restarted networking and everything went fine. I then did the same thing on the production machine:
I changed:
" gateway 10.10.10.1"
to:
" #gateway 10.10.10.1"
and everything blew up!
When I then changed it instead to this:
"# gateway 10.10.10.1"
everything worked fine again.
In the interfaces file at least, it’s *very* important to put comment tags as the first letter of a line you want to comment.