Summary: Duplicate Packets

From: Christopher E. Olaes (
Date: Mon Jul 28 1997 - 10:54:36 CDT

Hello Everyone,

My original post was:

> Hi Everyone,
> I recently added two more ethernet interfaces to my sparc 1000E server...
> However when I ping the server now, I get the following output:
> 64 bytes from icmp_seq=0 ttl=255 time=1.1 ms
> 64 bytes from icmp_seq=0 ttl=255 time=3.9 ms (DUP!)
> 64 bytes from icmp_seq=1 ttl=255 time=1.0 ms
> 64 bytes from icmp_seq=1 ttl=255 time=1.5 ms (DUP!)
> 64 bytes from icmp_seq=1 ttl=255 time=1.8 ms (DUP!)
> 64 bytes from icmp_seq=2 ttl=255 time=2.4 ms
> 64 bytes from icmp_seq=2 ttl=255 time=7.2 ms (DUP!)
> 64 bytes from icmp_seq=2 ttl=255 time=7.6 ms (DUP!)
> I get similar output on all ethernet ports on the server.....
> These duplicate packets seem to be hindering my nfs performance over the net.
> Is there anyway, to fix this?
> Any helps would be appreciated...
> Thanks
> Chris
> --


Given that I had a computer that had three network interfaces... I assumed
that each network interface had its own ethernet address. And as some of you
have noted, "by default sun assigns my ethernet address per computer" which
means that no matter how many ethernet cards you add, you still only have
one address.. Now this is fine if you have your machine on different subnets,
but not so good if the ethernet interfaces are on the same subnet.

So as suggested, I used the ether option of the ifconfig program to give
each network board its own unique ethernet address. Now since, I was unsure
what address to use, for fear of conflict... I took the address off of two
dad ethernet boards that I had for my pc laying around... I then disposed of
those network board forever.

To make the changes current everytime the system is rebooted.. I put the
following command in:


ifconfig le1 xx:xx:xx:xx
ifconfig le3 xx:xx:xx:xx

Where le1 and le3 are my two new network interfaces and the
xx:xx:xx:xx are the ethernet address I used....

Thanks to everyone to replied...

Kamal Kantawala
Lee Whitty
Seth Rothenberg
Bob Woodward
Casper Dik
Frank Pardo
Rich Kulawiec


*Christopher E. Olaes                           Network Administrator        *
*                                               National Institutes of Health*
*Phone (301)496-3275                            10 Center Drive, MSC-1061    *
*Beeper(301)701-4442                            Building 10, Room B1D161     *
*                                               Bethesda, MD 20892-1061      *

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