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Conference turris::digital_unix

Title:DIGITAL UNIX(FORMERLY KNOWN AS DEC OSF/1)
Notice:Welcome to the Digital UNIX Conference
Moderator:SMURF::DENHAM
Created:Thu Mar 16 1995
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:10068
Total number of notes:35879

9642.0. "Limit on interfaces per subnet?" by CSC32::A_LICAUSE () Mon Apr 28 1997 15:24

    I have a very novice customer that has tried to use two 10Mbps Ethernet
    interfaces and two 10/100Mbps interfaces on the same system....
    	ALL IN THE SAME SUBNET!!!
    
    The first two seemed to operated or at least can be ping'd locally and
    remotely, but the DE500's would not return a local ping.
    
    I had him put an address alias in a different subnet, on one of his DE500's 
    and he was then able to ping the alias.  
    
    My question:  is there something in the drivers or the ip stack of any
    version of dunix that will prevent a system from recognizing or responding 
    to more than two interfaces in the same subnet?
    This happens to be V3.2g of dunix.
    
    Thanks
    Al
T.RTitleUserPersonal
Name		DateLines
9642.1Configuration problem?NNTPD::"[email protected]"Brian HaleyMon Apr 28 1997 18:5117
Hi,

How where the DE500's setup.  If they were setup in 100MB/s mode and on a
10MB/s Ethernet, I wouldn't expect them to work.  Did they get any messages
on the console when booting and these devices were being probed?  I'm not
sure what the driver does when the adapter can't get a link.  Either way,
it's not a worthwhile configuration.

What was their reason to try this setup anyways?  If they assumed they were
going to get some load-balancing out of it, they were wrong.  The routing
table will have only one interface tagged as the default to that subnet, the
remaining three won't be used for any outbound traffic.  Inbound packets can
be addressed to any interface without a problem, but that doesn't get you
very much.

-Brian
[Posted by WWW Notes gateway]
9642.2Ignorance is blistering!CSC32::A_LICAUSEMon Apr 28 1997 22:5423
    Brian,
    
    Thanks very much.  I don't really think this customer knows exactly
    what they want to do.  They certainly don't know how to go about it!
    
    Unfortunately they couldn't really explain what they wanted to do and
    how they thought they were going to use what they had, but someone
    in the shadows was acting like an expert!  They wanted to know the
    RFC #'s to consult the "read experts".....I suggested they do a little
    reading in some of the more popular text for starters.  
    
    RE:. the DE500's.  In this case they were setup for 10Mbps operation.
    
    Funny thing was that I just spoke to a customer last week that was
    doing something very similar but with two interfaces.  They were
    using one for local users and the other for remote users.  They
    explicitly directed the users to particular interfaces using static
    routing on the clients.  It worked until it broke at which point
    I suggested they use two subnets....if for no other reason than
    to be able to test when it did break.
    
    Al