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Conference netcad::hub_mgnt

Title:DEChub/HUBwatch/PROBEwatch CONFERENCE
Notice:Firmware -2, Doc -3, Power -4, HW kits -5, firm load -6&7
Moderator:NETCAD::COLELLADT
Created:Wed Nov 13 1991
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:4455
Total number of notes:16761

4366.0. "GIGAswitch IP packet switching support" by NNTPD::"bichsel@mail.dec.com" (Walter Bichsel) Thu Apr 17 1997 20:01

T.RTitleUserPersonal
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DateLines
4366.1CSC32::bngpc.cxo.dec.com::goodwinBrad Goodwn - NSISThu Apr 17 1997 21:5322
All DEChub modules that have an on-module SNMP agent support default gateway,
including the DEChub900 MAM, unless they are some very old firmware revs:

DECrepeater 90TS - slot 3
==============================================================================

DECrepeater 90TS, 8 port TP Ethernet Rptr SNMP, HW=v3,RO=v01.00,SW=V2.1.1
SysUpTime                                 : 71 days 04:00:29   28 resets
SNMP Read/Write Community                 : public
SNMP Trap Addresses                       : Not Configured
Status of Last Downline Upgrade           : No Status
BootP                                     : Disabled

Interface     IP Address      Subnet Mask     Def. Gateway    Other Info
---------     ----------      -----------     ------------    ----------
Ethernet Port 16.63.112.55    255.255.0.0     16.63.0.1       08-00-2B-B2-DB-A4
Hub Mastership Enable                     : Off
Hub Master Configuration                  : Not Configured

==============================================================================


4366.2don't set the default gateway to your address!NETCAD::MCCRORYFri Apr 18 1997 18:1028
  >4.3   End Station Modifications
  >
  >In order for IP packet switching to work properly the end stations must be 
  >modified so they will attempt to send directly to every destination - even 
  >destinations in different subnets.  This will require that they ARP for every 
  >destination address.  In most operating systems this can be accomplished by 
  >setting the default gateway IP address equal to the end stations own IP 
  >address.
    
    Well ... don't do it the way that they suggested ... setting the default
    gateway address to your own address!  I haven't actually tried this but
    I'm pretty sure that setting the default gateway to your own address
    will fail.
    
    In the OLD versions we supported default gateways but not subnet
    masks (and I won't get in to the explanation of why we did this.)
    To directly send to systems outside of your subnet you'll need to
    set the default gateway address to zero ... when there's no default
    gateway all messages will be sent directly to the destination.
    
    In the newer versions of the software we do support default gateways
    and subnet masks.  To send directly to systems outside of your subnet
    you need to set the subnet mask to 0.0.0.0.  Using that mask it
    looks like everybody is in our subnet so we send directly to every
    destination. 
    
    -Eileen
           
4366.3My God, someone read the spec! Wow, someone working on IP can read!TWICK::PETTENGILLmulpWed Apr 23 1997 01:5512
Years ago Jeff Mogul, I think, in the RFC specifying subnet via masks said
that the class stuff should no longer be used to make the decision to route
or send directly.  That was well before it was necessary to go to "supernetting"
but did anyone pay any attention?  Of course not.  Especially the people working
on the "reference" code included in bsd.

The hack described (setting the default gateway to self) is required to get
the code to branch to the arp code after its been waylaid by the class A/B/C
branching code.

Ah, I get it, this must be some special DEC trick to make IP proprietary....
That evil DEC....