On Wed, Nov 7, 2018 at 9:57 PM Dan Cross <crossd@gmail.com> wrote:

> On Wed, Nov 7, 2018 at 4:05 AM <arnold@skeeve.com> wrote:
>
>> When DNS came along, it became
>> a matter of editing /etc/nsswitch.conf to include dns as one of the
>> options along with files and yp/nis.  I think the average user didn't
>> see any big difference since all the apps (ftp, telnet) just went
>> through gethostbyname().
>>
>
> This doesn't mesh with my memory. I recall building BIND from source and
> having to rebuild network programs (e.g. on 4.3 on the RT or VAXen) to pick
> up the new version of libresolv.a, and hacking the resolver library into
> libc.so on Suns. I remember using resolv.conf fairly early on, but my
> memory is that nsswitch.conf came later (Solaris 2.x era?). Ultrix did have
> a configuration file for where to do host lookups, but I think the set of
> sources was fixed: files, NIS or DNS.
>

I always assumed that nsswitch came much later than DNS, based just on the
fact that Linux glibc on older systems still ships an /etc/host.conf
"resolver configuration file" that has such parameters as "order
hosts,bind,nis" (although they're inoperative).

-- 
Mantas Mikulėnas