Bug 416581

Summary: NTP multicast client does not work
Product: [Fedora] Fedora Reporter: Vlado Potisk <reg.bugs>
Component: ntpAssignee: Miroslav Lichvar <mlichvar>
Status: CLOSED NOTABUG QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: low Docs Contact:
Priority: low    
Version: 8   
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Target Release: ---   
Hardware: i386   
OS: Linux   
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Fixed In Version: Doc Type: Bug Fix
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Clone Of: Environment:
Last Closed: 2007-12-12 16:45:29 UTC Type: ---
Regression: --- Mount Type: ---
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description Flags
output of ntpd -n -D 5 none

Description Vlado Potisk 2007-12-08 16:02:17 UTC 
Description of problem:
NTP multicast client doesn't work.

Version-Release number of selected component (if applicable):
ntp-4.2.4p2-6

How reproducible:
Always

Steps to Reproduce:
1. configure NTP as multicast client and start it
  
Actual results:
NTP started normally, but time get's never synced, ntpq shows no associations.
There are error in logs:
ntpd[3893]: Listening on interface #6 multicast, 224.0.1.1#123 Enabled
ntpd[3893]: setsockopt IP_ADD_MEMBERSHIP failure: No such device on socket 22,
addr 224.0.1.1 for 10100e0 / 0 (224.0.1.1)
ntpd[3893]: Failed to add Multicast Listener 224.0.1.1

Expected results:
Time synced to the multicast server.

Additional info:
The same setup configured as broadcast client works fine (that's the workaround
I'm using now). Fedora Core 6 multicast client works fine on the same LAN.
Comment 1 Miroslav Lichvar 2007-12-11 11:57:29 UTC 
It works for me. Any chance you are using a custom kernel?

If not, please attach here the output of /usr/sbin/ntpd -n -D 5.
Comment 2 Vlado Potisk 2007-12-11 14:49:33 UTC 
No custom kernel.

I have now another Fedora 8 machine (different hardware) that has no multicast
problem with exactly the same config. Maybe is the problem hardware related. The
computer in question has Intel D201GLY maiboard with integrated SiS900 ethernet
card.
Comment 3 Vlado Potisk 2007-12-11 14:50:49 UTC 
Created attachment 284111 [details]
output of ntpd -n -D 5
Comment 4 Miroslav Lichvar 2007-12-12 15:54:22 UTC 
The error means kernel couldn't choose an interface for the multicast group.
Maybe the default route is missing? Does it work when you add the following route?

route add -net 224.0.0.0 netmask 240.0.0.0 dev eth0
Comment 5 Vlado Potisk 2007-12-12 16:45:29 UTC 
Yes that was it ! I do appreciate your help.

The computer is behind a proxying firewall, there is no real route out. The
other host has the default route (not usable, but present), that's why that one
was working.

I knew that a route for the 224 network is important for sending multicast
traffic, but I did not know it is needed for receiving it too. Sorry for this
false bug report, I'm closing it now.