Bug 915147

Summary: redhat-lsb breaks hostname lookup of machines on local network
Product: [Fedora] Fedora Reporter: Eddie Kovsky <ewk>
Component: redhat-lsbAssignee: Ondrej Vasik <ovasik>
Status: CLOSED DUPLICATE QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: 18CC: ewk, hliu, llim, ovasik, pnemade
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Hardware: x86_64   
OS: Linux   
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Fixed In Version: Doc Type: Bug Fix
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Last Closed: 2013-11-25 17:23:14 UTC Type: Bug
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description Flags
Update redhat-lsb install to prevent breaking nsswitch.conf none

Description Eddie Kovsky 2013-02-25 04:45:10 UTC 
Description of problem:
Installing redhat-lsb package appears to break hostname resolution of machines on local area network. 

After installing redhat-lsb, I tried to connect to another machine on my network via SSH. Both command line ssh and Gnome 3 file browser return same error: 
  "Unable to access location"
  "Hostname not known"
Machine on local network also stops responding to ping requests.

Version-Release number of selected component (if applicable):
redhat-lsb         x86_64         4.1-10.fc18

How reproducible:
I isolated this after installing Google Chrome. Google adds a third party repository for the Chrome browser, and then adds packages from the Fedora repos as dependencies: 

google-chrome-stable   x86_64   25.0.1364.97-183676
redhat-lsb             x86_64         4.1-10.fc18
libpng12                 x86_64       1.2.50-2.fc18
redhat-lsb-desktop       x86_64       4.1-10.fc18

I uninstalled each package individually. Uninstalling redhat-lsb restored network functionality. 

Steps to Reproduce:
1. ssh to another machine on the LAN
2. 'sudo yum install redhat-lsb'
3. ssh to the same machine results in error: "Unable to access location"
  "Hostname not known"
4. 'sudo yum erase redhat-lsb' allows ssh to work again
  
Actual results:


Expected results:


Additional info: I could not find any bug reports filed against redhat-lsb, Chrome, or the network error message I'm seeing. I do apologize if this is a duplicate bug. 

Please let me know if I can provide any additional info.
Comment 1 Ondrej Vasik 2013-02-25 09:18:49 UTC 
redhat-lsb installation modifies /etc/nsswitch.conf to be LSB compliant. This may break its functionality - but the old system /etc/nsswitch.conf is kept as /etc/nsswitch.conf.rpmsave and user is warned about it. If this is the thing which broke your network connection, I'm sorry but there is no clean solution for this. Could you please check if this is your case?
Comment 2 Eddie Kovsky 2013-02-26 03:43:53 UTC 
Restoring the hosts entry from /etc/nsswitch.conf.rpmsave resolved this. I had to restore this entry from the backup: 

#hosts:     db files nisplus nis dns
hosts:      files mdns4_minimal [NOTFOUND=return] dns
Comment 3 Eddie Kovsky 2013-03-06 05:06:30 UTC 
Created attachment 705764 [details]
Update redhat-lsb install to prevent breaking nsswitch.conf

LSB requires nssswitch.conf to resolve host services in this order:

hosts: files dns

redhat-lsb installtion restores mdns4_minimal from hosts services entry. This breaks hostname resolution on local networks. 

Proposed patch appends mdns4_minimal to end of hosts lists. This way nsswitch.conf is still LSB compliant, but no longer breaks user's network configuration. 

I was able to build and install a local RPM with this patch without any errors.
Comment 4 Ondrej Vasik 2013-11-25 17:23:14 UTC 
This change breaks other things... as I do plan to remove the nsswitch handling at all, closing this as duplicate of F19 bugzilla tracking the same issue...

*** This bug has been marked as a duplicate of bug 986728 ***