pboin's questions

For my residential service, I changed ISPs to Zoom/Armstrong. Just after that, my NTP daemons stopped working. I dug deep and diagnosed the problem:

Unprivileged ports are getting out. When i run 'ntpdate' for example, I go out on a high, unprivleged port, and get a response on UDP 123. That's fine. The 'ntpd' daemon though, expects to go out on 123 and get its reply there as well. This must be a common problem, because it's directly addressed in the NTP troubleshooting guide.

Just to see what would happen, I wrote a detailed email to the general support address at Armstrong. They replied almost immediately with a complete technical answer! They have everything <1024 blocked, except for a few ports to support outbound VPN.

So, the question:

Can I use IPtables to essentially re-write my outbound UDP 123 up to 2123 or something like that? If I do, does there need to be a corresponding 2123->123 rule to translate the reply? This seems like NAT, but with ports, not addresses. I tried, but can't seem to get iptables to do what I want. I'm not sure if it's my lack of skill, or if I'm trying the wrong solution.

True, I could run ntpdate from cron, but that loses all of the adjustment smarts of NTP.

I'm trying to programatically stomp on bluetooth on RHEL5.

I've got the service stopped -- no problem. Also no problem on rpm -e for the associated bluetooth packages, bluez-*.

ps -aef | grep -v grep | egrep -c '(sdpd|hcid)'

returns zero , so I know the daemons are gone.

For some reason, I just can't get the modules to unload. modprobe -rv keeps saying they're in use.

Dependencies look like this:

bluetooth -> bnep
          -> l2cap 
                 -> rfcomm
                 -> hidp
          -> rfcomm
          -> hidp

But, even starting at the top so that dependencies are simple, modprobe -rv bluetooth returns FATAL: Module bluetooth is in use.

So, how do I find out what processes are using this module? It doesn't seem to be in /proc/modules, or lsof.

Command lsof still shows something hooked.

# lsmod | egrep '(bnep|hidp|rfcomm|l2cap|bluetooth)'
bnep                   82241  0 
hidp                   83521  0 
rfcomm                104809  0 
l2cap                  89281  5 bnep,hidp,rfcomm
bluetooth             118597  4 bnep,hidp,rfcomm,l2cap