Bug 23862 - Dns.GetHostAddresses("localhost") != 127.0.0.1
Summary: Dns.GetHostAddresses("localhost") != 127.0.0.1
Status: NEW
Alias: None
Product: Class Libraries
Classification: Mono
Component: System (show other bugs)
Version: 3.2.x
Hardware: PC Linux
: --- normal
Target Milestone: Untriaged
Assignee: Bugzilla
URL:
Depends on:
Blocks:
 
Reported: 2014-10-15 17:05 UTC by Peter Hultqvist
Modified: 2014-10-15 17:11 UTC (History)
1 user (show)

Tags:
Is this bug a regression?: ---
Last known good build:

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Status:
NEW

Description Peter Hultqvist 2014-10-15 17:05:09 UTC
This issue appears when the server hostname is set to "localhost".
This happened to be the default on some vps hosting services.

1. Run: hostnamectl set-hostname localhost

2. Run some tests

2a.# ping localhost
   64 bytes from localhost (127.0.0.1): icmp_seq=1 ttl=64 time=0.041 ms

2b.# host localhost
   localhost has address 127.0.0.1
   localhost has IPv6 address ::1
 
3. Run the following

    var ip = System.Net.Dns.GetHostAddresses("localhost")

Expected result:

ip = [127.0.0.1]

Actual result:

ip = [100....., 192.168....., 172......]

These are all 3 the IP addresses of the network interfaces.
Note that 127.0.0.1/8 is not there.