Re: VB6 DCOM weirdness with HOSTS file after installation of XP SP2

From: Tony Proctor (tony_proctor_at_aimtechnology_NoMoreSPAM_.com)
Date: 11/26/04 

Date: Fri, 26 Nov 2004 14:53:15 -0000

Hmm! Just re-read your question...

All TCP/IP s/w should be resolving addresses the same way, e.g. HOSTS first,
then DNS. I guess you can ping these new TestName/TestName2 names OK, can
you Rens?

It sounds like the names are being resolved OK for DCOM, but maybe different
security implications are associated with a resolution from HOSTS as opposed
to DNS. However, I'm afraid I don't know enough about what was changed in XP
SP2 to suggest what, or why. There are usually differences specifying
127.0.0.1 over localhost or the local machine name because any numeric IP
address is considered part of the Internet zone (i.e. 127.0.0.1 would have
to be added as a trusted site), but I don't think that's relevant here.

Sorry I can't really help

        Tony Proctor

"Rens Segaar" <r.segaar@beveco.nl> wrote in message
news:OJZfmD80EHA.1124@tk2msftngp13.phx.gbl...
> Tony,
>
> Thanx for your response. I had seen this particular thread passing by in
my
> search for an answer. I have actually been able to deal with similar
> problems and got all of DCOM working (even without setting everything to
> ANONYMOUS LOGON remote access permission).
>
> The problem I describe is of a somewhat different nature. It is only a
> problem on a local machine and then only if I try to use the local machine
> through its own IP address, which is in the HOSTS file.
>
> Anybody having more ideas...
>
> Rens Segaar
>
>
> "Tony Proctor" <tony_proctor@aimtechnology_NoMoreSPAM_.com> wrote in
message
> news:ewgJ8870EHA.3108@TK2MSFTNGP12.phx.gbl...
> > Seems to be a common theme Rens. XP SP2 seemed to tighten up a lot on
> > security. Is there anything in this similar thread that rings a bell?
> >
http://www.google.ie/groups?hl=en&lr=lang_en&safe=off&threadm=%23RRgypWiEHA.3996%40tk2msftngp13.phx.gbl&rnum=1&prev=/groups%3Fas_q%3DSP2%2520permission%2520dcom%2520xp%26safe%3Doff%26as_ugroup%3D*.vb%26lr%3Dlang_en%26hl%3Den
> >
> > Tony Proctor
> >
> > "Rens Segaar" <r.segaar@beveco.nl> wrote in message
> > news:erVfUz60EHA.1124@tk2msftngp13.phx.gbl...
> >> Hi all,
> >>
> >> Finally I got around to start testing one of our major products -
heavily
> >> based on VB6 EXE servers and DCOM - for compatibility with XP SP2.
And -
> >> luckily - I got things going finally, except for one little thing...
> >>
> >> Got this ordinary (for testing purposes very simple) VB6 client
> > application
> >> and (again for testing purposes very simple) VB6 EXE server. The client
> >> 'instantiates' the EXE server using the CreateObject() function. Mind
> >> you,
> > I
> >> got all this working across two computers (without setting everything
> >> open
> >> and with the firewall enabled and the two computer not being in the
same
> >> domain). The following are all local scenarios:
> >>
> >> CreateObject(myserver, "") -- OK (logically)
> >> CreateObject(myserver, "127.0.0.1") -- OK
> >> CreateObject(myserver, "localhost") -- OK (even when localhost is
> >> removed from the HOSTS file)
> >> CreateObject(myserver, "192.168.200.23") -- OK (where the IP
> > address
> >> is the address of the local machine)
> >> CreateObject(myserver, "192.168.1.1") -- OK (where the IP address
is
> >> mapped onto a Microsoft Loopback-adapter)
> >> CreateObject(myserver, mycomputername) -- OK
> >>
> >> CreateObject(myserver, "TestName") -- FAILS (where TestName is in
the
> >> HOSTS file and maps onto 192.168.200.23)
> >> CreateObject(myserver, "TestName2") -- FAILS (where TestName2 is in
> > the
> >> HOSTS file and maps onto 192.168.1.1)
> >>
> >> In both cases the error is a (70) Permission Denied error. There is
some
> >> kind of lookup taking place, because when a try a fake name (one that
is
> > not
> >> in the HOSTS file) the error returned is (462) The remote server
machine
> >> does not exist or is unavailable.
> >>
> >> Somehow the name resolution is locked out (??).
> >>
> >> All this was working OK prior to installing SP2.
> >>
> >> Turning off the firewall and/or further relaxing DCOM security settings
> > have
> >> no effect on this issue.
> >>
> >> You may wonder why I want this to work at all, given all the other
> >> possibilities, but within our existing code this is the way it was
> >> implemented in the past and we want this funcitionality back in order
not
> > to
> >> have to rewrite a very huge part of our code.
> >>
> >> Any idea? Anyone?
> >>
> >> TIA,
> >> Rens Segaar
> >> senior software engineer
> >> www.beveco.nl
> >>
> >>
> >
> >
>
>

Relevant Pages
Loading