b7e693fb   
   From: barmar@alum.mit.edu   
      
   In article   
   <33241120.296.1318942054266.JavaMail.geo-discussion-forums@vbat14>,   
    Bluz  wrote:   
      
   > Hi Barry,   
   >   
   > Thanks a lot for your quick response !   
   >   
   > You are absolutely correct indeed, the bigger problem being that all the   
   > other machines on the 10.0.0.0/8 subnet trying to reach machines on the   
   > 10.0.0.0/9 subnet will fail, and that is precisely what I am trying to   
   > understand. Is this because of the way TCP/IP subnetting is designed ? But   
   > you seem to say that is technically possible ?   
   >   
   > fact is :   
   > eth0 = 10.255.255.254/8 interface *cannot* ping eth1 = 10.127.255.253/9   
   > but   
   > eth1 = 10.127.255.253/9 interface *can* ping eth0 = 10.255.255.254/8   
      
   I'm not sure what you're saying here.  Those IPs are on the same   
   machine, how could they not be able to ping each other?  I guess you   
   actually mean other machines connected to these two interfaces.   
      
   But it's still not possible that X can ping Y, but Y can't ping X.  Ping   
   requires bidrectional communication -- X sends an ICMP Echo to Y, and Y   
   sends an ICMP Echo Reply back to X.   
      
   > I am ok closing the case saying right, with the above explanation in mind,   
   > let's say that the big doll cannot see the small doll because the target   
   > address is not where the machine would expect it to be, but you said it   
   > sounds like a bug to you, and that you have implemented a similar head   
   > scratching network on Cisco equipments a while ago.   
      
   I said it was a bug that the router itself can't reach machines on both   
   subnets, which was the problem you described in your initial post.   
      
   --   
   Barry Margolin   
   Arlington, MA   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)