On Tuesday, 12/19/2006 at 07:59 ZE2, Shimon Lebowitz <[EMAIL PROTECTED]> wrote: > <confused> > I don't think I understand what you are saying. I put > the altered version of TCPIP DATA on TCPIP2's (my test stack > userid) so that the stack would see the DNS lines, doesn't > PING run in the TCPIP2 user itself? The 191 is accessed > ahead of 592, so doesn't TCPIP2 know about the DNS? > </confused>
No, PING does not run in the stack. There is a low-level ICMP ECHO (ping) function in the stack that is invoked by the PING program, but that interface expects an IP address as input. DNS resolution is always done in the client virtual machine. > > We used to say that it was a good idea to run the cache-only resolver > > that comes with VM TCP/IP (i.e. NAMED) to avoid excessive DNS lookups > > going outside VM. Some installations also used it to prime the cache > > with a set of important host names (in case the outboard DNS was not > > available). But the VM DNS implementation has become a bit dated, so > > if you can you should probably avoid that route. > > Hmmmm.... "used to say it was a good idea".... "you should > probably avoid that route"? > I actually tried to start NAMSERV )or whatever the builtin > DNS is called), including putting the two DNS server > addresses in FORWARDERS(?), but it didn't help. > I am home now, so I might not remember keywords correctly. A caching-only DNS server is useful if you have a lot of CMS-based DNS lookups and you're having DNS-related performance problems. Other operating systems maintain their own caches, so pointing them to VM's DNS server doesn't have much value. It's far easier if you just point your NSINTERADDR entries to your "normal" DNS servers. Then, whatever the DNS problem du jour is, it isn't your fault. :-) Faster machines and faster networks have all done much to erase the benefit of a caching-only DNS server. Having said that, would there be torches and pitchforks awaiting us at the next conference if we chose to remove the VM DNS server from the suite of supported apps? (No plans...just a Grinchy idea.) Alan Altmark z/VM Development IBM Endicott
