since I didin't get ntp to work using pps due to a noisy pps line as it looks, I switched over to simple nmea in order go have at least something to synchronize my clocks, because it is crucial that they are...

That worked out of the box and all of a sudden just stopped. Since I changed a lot of things in order to make the box work fully-automatic, I can't say for sure if I broke something or what happened.. Still I am very puzzled...

Maybe I overlooked something?

Here's some information:

Here's my ntp.conf:-------------------------------
driftfile /var/opt/ntp.drift

# NMEA GPS driver for u-blox receiver
server 127.127.20.0 prefer #minpoll 4
fudge 127.127.20.0 flag3 0
#fudge 127.127.20.0 flag3 0 flag2 0 time1 0.124

server 0.debian.pool.ntp.org iburst
#server 1.debian.pool.ntp.org iburst
--------------------------------------------------

And here what I get with it:

     remote           refid      st t when poll reach   delay   offset  jitter
=========================================================================== ===
 GPS_NMEA(0)     .GPS.            0 l    -   64    0    0.000    0.000   0.001
*hahler.de       87.239.10.190    3 u   48   64    1   53.368  -122.54   1.601
--------------------------------------------------

ntpd -d log:
zeitserver:/usr/local/src/ntp-4.2.4p5# ntpd -d
ntpd 4.2....@1.1541 Fri Aug 22 14:38:35 UTC 2008 (1)
addto_syslog: precision = 1.000 usec
addto_syslog: ntp_io: estimated max descriptors: 1024, initial socket boundary: 16
addto_syslog: Listening on interface #0 wildcard, 0.0.0.0#123 Disabled
addto_syslog: no IPv6 interfaces found
addto_syslog: no IPv6 interfaces found
addto_syslog: Listening on interface #1 lo, 127.0.0.1#123 Enabled
addto_syslog: Listening on interface #2 eth1, 192.168.1.100#123 Enabled
local_clock: time 0 offset 0.000000 freq 0.000 state 0
addto_syslog: kernel time sync status 0040
addto_syslog: frequency initialized -2.200 PPM from /var/opt/ntp.drift
peer_crypto_clear: at 0 next 0 assoc ID 31820
peer_clear: at 0 next 1 assoc ID 31820 refid INIT
refclock_setup fd 5 modem status: 0x26
refclock_ioctl: fd 5 flags 0x1
addto_syslog: refclock_nmea: time_pps_create failed: Operation not supported
newpeer: 127.0.0.1->127.127.20.0 mode 3 vers 4 poll 6 10 flags 0x10a1 0x1 ttl 0 key 00000000
addto_syslog: refclock_nmea: time_pps_getcap failed: Invalid argument
peer_crypto_clear: at 0 next 0 assoc ID 31821
peer_clear: at 0 next 2 assoc ID 31821 refid INIT
newpeer: 192.168.1.100->131.234.137.23 mode 3 vers 4 poll 6 10 flags 0x201 0x1 ttl 0 key 00000000
local_clock: time 0 offset 0.000000 freq -2.200 state 1
report_event: system event 'event_restart' (0x01) status 'sync_alarm, sync_unspec, 1 event, event_unspec' (0xc010)
refclock_transmit: at 1 127.127.20.0
auth_agekeys: at 1 keys 1 expired 0
timer: interface update
addto_syslog: no IPv6 interfaces found
addto_syslog: no IPv6 interfaces found
nmea: gpsread 72 $GPGGA,151022.00,5225.83871,N,01316.84595,E,1,07,0.99,39.8,M,44.9,M,,*60
transmit: at 2 192.168.1.100->131.234.137.23 mode 3
receive: at 2 192.168.1.100<-131.234.137.23 mode 4 code 1 auth 0
peer 131.234.137.23 event 'event_reach' (0x84) status 'unreach, conf, 1 event, event_reach' (0x8014)
clock_filter: n 1 off -0.153899 del 0.057430 dsp 7.937501 jit 0.000001, age 0
nmea: gpsread 72 $GPGGA,151023.00,5225.83872,N,01316.84590,E,1,07,0.99,40.0,M,44.9,M,,*61
nmea: gpsread 72 $GPGGA,151024.00,5225.83874,N,01316.84583,E,1,07,0.99,40.1,M,44.9,M,,*63
^Caddto_syslog: ntpd exiting on signal 2

Thx for looking into it and best regards,
../nico

Go back up and look at the config file.  The default for the NMEA driver
is to expect GPRMC sentences.  So you should either fix your unit to
send them (and not waste time with the GPGGA stuff) or fix your config
file to use the GPGGA sentences.  I think that takes a mode subcommand.

--
These are my opinions, not necessarily my employer's.  I hate spam.

Best regards,
../nico berndt