OS 4.0, YP, and named

[Frank W. Peters]

Sun Yellow Pages as released with 4.0 (I have no experience with 3.x
versions) has two problems with using the Domain Name System.

First, it won't work. :-)  The following is a quote from the README
included with the fix:

 Problem description:

   YP link to resolver for name resolution does not seem to work.
   Little documentation exists to support this setup.  The
   makedbm -b option is supposedly necessary for interdomain
   name lookup.  The makedbm -b option does add a YP_INTERDOMAIN
   key to the hosts map however interdomian host resolution still
   fails under YP.

   Also, due to an uninitialized variable, programs that are linked static     
   (such as mount) that do YP host name lookups can hang if the ypserv 
   is using the inter-domain resolver (ypserv -i in 3.x or makedbm -b  
   in 4.x). 

 Fix description:

   A problem exists with the case respresentation for the string
   "YP_INTERDOMAIN" within ypserv which causes ypserv not to 
   recognize the host map interdomain key reference built by
   makedbm for the name service resolver link.  This a fixed
   68020 version ypserv only for use on a Sun3 running SunOS 4.0.
   Also fixes obscure bug that caused mounts to hang, and local names
   to hang when the name server was down.

   Also note that another problem exists related to ypxfr
   transfer of yp master host map data to slave servers
   resulting in the slave server unable to serve as a resolver 
   link.  This is a fixed 68020 ypxfr version which will
   allow Sun3 4.0 yp slave servers to receive correctly built
   host map data from a 4.0 yp master server and link with
   the resolver as a slave server.

The fix to this problem is included with 4.0.1

The second problem is only relevant to suns acting as both a nameserver
and YP master. This symptoms are that if the link to the root name servers
is broken (say a gateway crashes) the server will begin to send repeated
packets to all of the root servers until it gets a response.  It sends
these packets JUST AS FAST AS IT CAN with NO pauses.  Our gateway used to
be one of the small 68000 based proteons and it couldn't keep up (which
meant our link would crash which meant the root servers were definitely
not reachable which meant the server kept banging which crashed the
gateway as it rebooted...  and so forth).  As if this weren't bad enough,
while all of this is going on the server will not be able to resolve names
IN ITS OWN YP MAPS OR DNS DATABASE.  This means that you can't rlogin or
telnet to the server or any of its clients and cannot nfs mount
filesystems  (see the end of the first paragraph under 'fix description'
above).  Any filesystems already mounted seem to be fine.

Sun also has fixes for this problem (by changes to the same executables as
above).  THESE FIXES ARE NOT INCLUDED IN 4.0.1.

Hope this information helps.  Drop me a note if you have any questions.

                     Frank Peters

Internet:  peters at CC.MsState.Edu
BITNET:    PETERS at MSSTATE.BITNET