[c-nsp] c877 and ntp oddness

[Kevin Graham]

> >> Have a bizarre NTP issue with 877 routers running 12.4(T) train.

> >>
> >> - Only seems to affect a small percentage of 877 routers,
> >> 878s, 1800s , 2800s seem to be fine
> > 
> > A coworker reported the exact same behavior a couple of weeks ago. They
> > got 87x routers with a new hardware revision, these routers do not sync
> > with ntp anymore. TAC case is open, but nothing concrete so far.

Are you sure its hardware related and release-specific? With the
introduction of NTPv4 in (22)T it appears NTP access-groups are broken,
requiring them to be removed or everything given 'peer' access. (Covered in
CSCsw79186, though the problem is much more widespread than release notes
there indicate).