127.0.0.1 vs 0.0.0.0


 
Thread Tools Search this Thread
Special Forums IP Networking 127.0.0.1 vs 0.0.0.0
# 1  
Old 08-17-2015
Network 127.0.0.1 vs 0.0.0.0

Which one should I use in '/etc/hosts'?
Please explain in details.

Random quotes on the topic:
Quote:
When you use the 0.0.0.0 method it doesnt try connect anywhere. But if you use 127.0.0.1 it actually tries to connect to a service on your computer which makes it take longer and use up more resources. Also you might run a webserver that it ask for invalid requests. Therefore it is better to use 0.0.0.0 than 127.0.0.1 as you want to kill the connection not to loop it back to your computer
Quote:
Why is it better? 0.0.0.0 doesn't connect anywhere. 127.0.0.1 does. If I run a web server that has a virtual host with the same domain name, it would serve the request.
Quote:
What does that have to do with 0.0.0.0? 0.0.0.0 has NO meaning on Linux, FreeBSD, or Mac OS-X and causes problems on those operating systems. The added benefit of using 127.0.0.1 is that the top phttpd (Pseudo HTTP Daemon) and Homer log what is being stopped and why.
Quote:
I have tested both ways in Windows XP and Windows Server 2003 only, and all I can tell so far is that using a template in this form:
127.0.0.1 google-analytics.com
127.0.0.1 ssl.google-analytics.com
is not good at all for my system, and it can slow down even the most common operations.

But I have found that using a template in this form:
0.0.0.0 google-analytics.com
0.0.0.0 ssl.google-analytics.com
seems to be ok as far as system stability is concerned, and even the webpages are loading faster.
# 2  
Old 08-17-2015
The culprit may be a "black hole" firewall response, which instead of refusing connection just stonewalls it by ignoring the attempt.
This User Gave Thanks to Corona688 For This Post:
# 3  
Old 08-18-2015
Unfortunately, 0.0.0.0 has different meanings depending on where it's used. The formal definition is given in RFC1122 Section 3.1.2.3, i.e this host on this network. Specifically, all available IP addresses on this host.

Assuming you are talking about a UNIX-like OS and not Microsoft Window, I have never seen 0.0.0.0 defined in /etc/hosts but have nearly always seen 127.0.0.1 defined. There simply is no reason to put 0.0.0.0 in /etc/hosts.
These 2 Users Gave Thanks to fpmurphy For This Post:
Login or Register to Ask a Question

Previous Thread | Next Thread

9 More Discussions You Might Find Interesting

1. UNIX for Advanced & Expert Users

wait - return code 127

Hi All, I am trying to create background processes and then check their status later. But I am getting return codes as 0,127 randomly On checking the return codes for wait, I found the below. Do I need to treat return code of 127 as successful as well?? as we know the process id passed is... (7 Replies)
Discussion started by: tostay2003
7 Replies

2. Solaris

multitude of packets from 127.0.0.1

I was checking routing table, and noticed that our server has a lot packets from localhost: Routing Table: IPv4 Destination Gateway Flags Ref Use Interface -------------------- -------------------- ----- ----- ------ --------- .. 127.0.0.1 127.0.0.1 ... (1 Reply)
Discussion started by: orange47
1 Replies

3. Solaris

sendmail problem, Connection refused by [127.0.0.1]

one of our sparc servers is having this problem: Jun 27 13:05:00 sparki sendmail: p5: from=root, size=309, class=0, nrcpts=1, msgid=<201106271305.p5@sparki>, relay=root@localhost Jun 27 13:05:00 sparki sendmail: p5: to=root, ctladdr=root (0/0), delay=00:00:00, xdelay=00:00:00, mailer=relay,... (3 Replies)
Discussion started by: orange47
3 Replies

4. Shell Programming and Scripting

Execution of shell script returns error 127

Hi All, While running shell script i got following output. interpreter "usr/bin/ksh" not found sh: step1.sh: not found. ldnhpux | oracle >echo $? 127 - Running command "which ksh" retruns "usr/bin/ksh". - I found some information on web stating to remove extra carriage return chars,... (8 Replies)
Discussion started by: RuchirP
8 Replies

5. HP-UX

logrotate: ALERT exitted abnormally with [127]

HP-UX B.11.23 U 9000/800 636114222 unlimited-user license I see this error in my logs sometimes and have very little info on it... I have searched online for some documentation and haven't been able to find much on this issue. The only thing I found on one site is that if my /tmp folder... (4 Replies)
Discussion started by: zixzix01
4 Replies

6. Solaris

Can't setup gateway other than 127.0.0.1?

I have just installed Solaris 10 X86 today, but I can't use internet at all on it. When I was installing it, it only asked me to create a hostname, without even asking me this computer is "networked" or "non-networked". After I finished installation, I use "netstat -rn" command, and only see... (3 Replies)
Discussion started by: Diamondust
3 Replies

7. Shell Programming and Scripting

rc=127 can't fork

I have a script to download a file using wget. It works if I execute it from the command line. But, if I run it in cron, it doesnt work and I am getting the following in the cron log: > CMD: /export/home/username/test > username 23159 c Tue Aug 1 14:40:00 2006 < username 23159 c Tue Aug ... (1 Reply)
Discussion started by: BG_JrAdmin
1 Replies

8. UNIX for Advanced & Expert Users

Serverhost 127.0.0 error message on apache

my apache 2.0 is up and running but after trying to reconfigure it for specifics I ended up with a permanent eror message that I can't seem to get rid of .. when I run the server ( just / */apachect1 start ) the message reads "cannot locate name localhost for server 127.0.0" so far I have tried... (2 Replies)
Discussion started by: moxxx68
2 Replies

9. Shell Programming and Scripting

Background processes return 127 sporadically

I have created a shell script that spawns multiple background processes (spawns sqlplus application). I use an array to capture the process id of those background processes. I then loop through the array and issue a 'wait' command to wait on the process id that was captured in the array. I am... (2 Replies)
Discussion started by: max_largo
2 Replies
Login or Register to Ask a Question