I disabled all my network connections and deleted 127.0.0.1 localhost in HOSTS file but cannot find what had I broken by it. My IIS and MS SQL Server 2008 R2 continues to resolve localhost just fine
Why does HOSTS file always contain 127.0.0.1 localhost ?
What had I broken by deleting this entry?
I am on Windows XP Pro SP3 writing here still without localhost in HOSTS file.
Should I put it back and how fast ?
The reasons of interest are many fold - for instance:
------ UPDATE05:
I am not changing the question! I add updates. Can I ask to stop deleting and editing it until I write that I fished with it? For ex., just now I wrote the same comment in all posts addressing the same point.
This is the essence of my question/doubt - that the DNS does not make any sense in relation to "localhost" or "127.0.0.222" or "(local)" names, synonyms, aliases, links, addresses, IDs, tokens, whatever.
They are hundreds synonyms to the same entity and they are internal and Windows-es know it without any resolutions since there is no sense to resolve between so many synonyms!
They are related to internal computer mechanisms while DNS is external (between various computers). How can internal IDs can depend on external ones?
All Windowses (including Home Editions) will have internal DNS server in order to function? and then replicate it when/if connected to network?
Well, the link from comments did not appear in Linked section, as I was told.
I forked a child subquestion:
https://stackoverflow.com/questions/3536351/is-localhost-host-resolved-to-127-0-0-1
Answer
The hosts file just associates canonical or fully qualified names to IP addresses.
For instance, I could have:
127.0.0.1 moes-bar-and-grill
Then anything connecting to moes-bar-and-grill would establish a connection to the loopback device, aka 127.0.0.1, commonly resolved as localhost.
I could also have (and this is quite common)
127.0.0.1 annoying-ad-server.com
Applications continue to work because they will connect to 127.0.0.1 (which is still a configured / up interface) if localhost does not resolve.
I'm not sure why you would want to disable the loopback address, but simply taking localhost out of your host file is not going to do that.
Edit
Well written software will make more than one attempt at resolving anything (resolving in a sense of working around problems, no pun intended) before it just dies and in some cases will continue to function even if things are not as expected. That does not mean that the software will work as advertised, it only means that it was written by a very defensive programmer.
Very defensive does not always mean helpful when it comes to telling the user that serious problems exist, for instance localhost not resolving. I can write stuff that passes tests no matter what a user does to their system, but that does nothing to promote the cause of "This won't work!". There is a stark difference between it runs and it works and you will only explore the difference between the two over time with every program that you run.
While everything seems to work, now, I think you may be headed for trouble later.
Disclaimer: I write software for a living.
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