stumped: cyrus-imap master hanging w/ "imap[506]: refused connection from ::1"

[Henrique de Moraes Holschuh]

On Sun, 07 Nov 2004, OpenMacNews wrote:
> i've cyrus-imap, cyrus-sasl, postfix and mysql+web-cyradm installed on OSX.

Versions, please!

>       imap[507]: executed
>       imap[506]: refused connection from ::1

This is libwrap doing something [in]sane.

>        /etc/hosts.allow
>             ALL: ::1 127.0.0.1 172.30.11.0/255.255.255.248

Does this work at all?  The IPv6 guys in Debian never tried to bust my hide,
so I assume at least Debian's libwrap know not to screw up with IPv6, but I
don't know about OSX...

>From the Debian changelog:
IPv6 support is provided by the 10_usagi-ipv6
and 11_usagi_fix patches, which are tcp_wrappers.usagi-ipv6.patch and
tcp_wrappers.ume-ipv6.patch from the Red Hat package.

So, unless Apple or the BSD* folks (which would be likely, I suppose)
patched their libwrap... you will have to disable it.

> (g) in order to reclaim CPU, i have to 'kill -9' the cyrus-imap 'master' 
> (NOT the postfix master ...) process.  originally, i thought it was killing 
> off mysql, but it's apparently correlary?

I have seen this on cyrus 2.1, when a child fails too early before doing an
accept(), and no fork limits are set on master.  If they ARE set, you get a
permanently screwed up master that tries to fork that service and never
suceeds, but at least the system doesn't get DoSed.

Cyrus 2.2 may not be suceptible to such problems.

> (h) some of the time -- not 100% reproducibly -- killing off the master 
> process causes something else (dunno yet) to die off as well, such that 
> none of my console processes respond ... e.g., a simple 'ls' does simply 
> nothing.

THIS means something is seriously busted on your operating system setup.

> any ideas where the problem *starts*?

Broken IPv6 support on libwrap and others...

-- 
  "One disk to rule them all, One disk to find them. One disk to bring
  them all and in the darkness grind them. In the Land of Redmond
  where the shadows lie." -- The Silicon Valley Tarot
  Henrique Holschuh
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