From: mds@bogus.nodomain.nowhere   
      
   Lew Pitcher  writes:   
      
   > On Thu, 29 Feb 2024 22:36:59 -0400, Mike Spencer wrote:   
   >   
   >> At times, using wicd, I disconnect from the router and reconnect via   
   >> wi-fi, using a cell phone served by ISP "B" as an access point.  Wicd   
   >> replaces /etc/resolv.conf with one that references the nameservers of   
   >> ISP "B".  Apps such as a web browser and Usenet news proceed as   
   >> expected after the change but sendmail fails to deliver messages to   
   >> the remote smarthost.   
   >>   
   >> Restarting sendmail fixes this.   
   > [snip]   
   >   
   > I think that you are trying to solve the wrong problem. The problem isn't   
   > that sendmail caches the address of the DNS server, but that you are   
   > using a DNS server who's address may change over time.   
   >   
   > You could just run a caching nameserver on your slackware box, and   
   > resolve /all/ DNS queries against that server. This way, the DNS   
   > server maintains a fixed address (perhaps, "localhost", in your case)   
   > and sendmail doesn't have to fish about for DNS resolution.   
      
   I never thought of that.  The caching nameserver would have to be able   
   to go to the right remote nameserver to update itself but that might   
   be handled correctly.  One more thing to maintain kinda contravenes my   
   preference for KISS but I'll have a look at that.   
      
   > A caching DNS server adds very little to the system overhead, and,   
   > beyond the initial setup, needs little or no maintenance. It gives   
   > the added benefit of adding a bit more security to your DNS queries,   
   > in that your ISP /does not/ handle the queries,  /can't/ log or track   
   > them, and /can't/ substitute their own sponsored/edited/redirected   
   > answers.   
      
   A potential problem, yeah.  IIRC, I've only seen it happen twice, once   
   using somebody's wi-fi where their router did DNS weirdly.  I forget   
   the details of the other case but it became publicly known and went   
   away after public protest.   
      
   Tnx,   
   --   
   Mike Spencer                  Nova Scotia, Canada   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)