Ok, well, so I can be sure that it's the broken build and not my config,
what
should the config look like ideally?
-Philip
If the router that is offering multicast NTP time service has an IP of 10.1.2.3
this would be the minimum config for a client. You may have to define the source
interface for NTP on a Cisco router:
multicastclient
restrict default ignore
restrict 224.0.1.1
restrict 10.1.2.3
server 127.127.1.0 # local clock (LCL)
fudge 127.127.1.0 stratum 10 # LCL is unsynchdronized
driftfile /etc/ntp/drift
I think it is easier to debug this by commenting out all "restrict" lines and seeing if it works.
If it does, your problems are with the ACL's. If it does not work the problem is elsewhere.
The lines for "server 127.127.1.0" and "fudge 127.127.1.0 stratum 10" allow NTP to take its time from localhost, if outside sources cannot be queried.
/etc/ntp/ needs to be writable by user ntp. In RH's ntpd, ntpd drops to user ntp after it starts. I find this file is often owned by root in RH, so you will never get a drift file written and long term time keeping will not be that good.
NTPd requites 4 separate sources for time so its "false ticker" algorithms will operate, allowing one source to go bad. 3 sources are required to offer long term accurate time.
james
