Malcolm.Harper@prg.oxford.ac.uk (11/02/90)
The host UK.AC.OX.PH is registered in the NRS, and users here (UK.AC.OX.PRG)
have been able to send mail to addresses of the form USER@PH, because of the
mapping
ph ph.ox.ac.uk
in one of our domain std files.
We've just added the top domain ph (derived from UKC's top domains), and
sendmail now decides (in ruleset 10) that the address USER@PH is already fully
qualified, so later fails with "Host PH unknown".
There doesn't seem to be any way to override this from the domain and channel
tables -- does anyone have any suggestions? There's a similar problem with
USER@MX which presumably should go to Middlesex, but doesn't because of
the top domain entry for Mexico.
There are another thirteen UK.AC hosts which have a top-level domain as the
last field of their NRS-ordered name, so perhaps someone else has already met
this locally.
-- Malcolm Harperjimc@quintus.com (Jim Crammond) (11/05/90)
| There doesn't seem to be any way to override this from the domain and channel | tables -- does anyone have any suggestions? There's no nice way to do this - you have to consider issues like where should user@ph.sun - is it a subdomain of ph.ox.ac.uk or is it sun.ph? A better example is "cs"; is hw.cs really heriot-watt.computer-science or some institution in Czechoslavakia? You basically have 2 choices: remove the top level domains like "ph" and "cs" and force users who really mean to mail to these countries to explicitly route through a uk gateway - user@ph can then route locally as it usually should; or do a clever trick. Here's one from the clever tricks department which basically stuffs extra rules in ruleset 10 to override the nameclash. Add the following rules to your local domain table: @ph @uk.ac.ox.ph # convert to nrs form @uk.ac.ox.ph @ph.ox.ac.uk # nrs to 822 form @mx @uk.ac.mx @uk.ac.mx @mx.ac.uk This also ensures that uk.ac.ox.ph is not considered a subdomain of ph. I think I would use the trick for ph and mx but would delete cs from the top level domain list. -Jim.
A.Macpherson@stl.stc.co.uk (Andrew Macpherson) (11/05/90)
I observe that in general mail is generated as replies --- the simple answer then is to always deliver a fqdn (Fully Qualified Domain Name) to the users' mailboxes (especially for the local site) and the problem is vastly reduced. Add to this explicit rules to deal with those poor unfortunates who need to re-register (delete) their short-forms, and the problem is cracked, specially if your "global-alias table" also uses fqdns. After all, you are going to rename your 'ph' (cs) host(s) aren't you? [[ Aside this list is form ambiguity as well --- Time you changed too! ]] Having made the transition to PP for the STC gateway I am glad to say that the problem has gone away for me. --- Internally everything is in strict 822 format, and only the greybook channel has to deal with reversals. The only difficulty remaining is education of users that "academic sites are a bit backward" ;-). -- A.Macpherson@stl.stc.co.uk - or - Post@stl.stc.co.uk "Quot homines, tot sententiae"