ntpd crashes every once in a while

[Guido Demmenie]

Hello,

ntpd crashes every once in a while, sometimes with days in between  
sometimes within a few hours.

And the error I see in my /var/log/messages is:
Jan 12 14:21:34 rottnic kernel: pid 516 (ntpd), uid 0: exited on  
signal 11 (core dumped)

My server is in the pool of pool.ntp.org and there is mentioned that  
I might have to raise my ulimit, but as shown below it is already  
unlimited as far as I can see.

rottnic# csh
rottnic# limit
cputime      unlimited
filesize     unlimited
datasize     524288 kbytes
stacksize    65536 kbytes
coredumpsize unlimited
memoryuse    unlimited
vmemoryuse   unlimited
descriptors  3463
memorylocked unlimited
maxproc      1731
sbsize       unlimited

rottnic# sh
rottnic# ulimit
unlimited

uname -a
FreeBSD rottnic.nl 6.0-RELEASE FreeBSD 6.0-RELEASE #0: Wed Mar  8  
19:48:39 CET 2006     rottweilertje@:/usr/src/sys/i386/compile/ 
ROTTKERNELv3  i386

I added this to my kernel:

options IPFIREWALL
options IPFIREWALL_VERBOSE
options IPFIREWALL_VERBOSE_LIMIT=10
options IPDIVERT
options IPSEC
options IPSEC_ESP
options DUMMYNET
options QUOTA

# Wireless AP support
wlan_wep        # 802.11 WEP support
wlan_ccmp       # 802.11 CCMP support
wlan_tkip       # 802.11 TKIP support
wlan_xauth      # 802.11 external authenticator support
wlan_acl        # 802.11 MAC ACL support


Thanks in advance,

Guido