?? about tcpdump output..

[Security <security@mail.decorah.net>]

Greetings, list;

I have been seeing this output from tcpdump  on eth0 on one of my machines.
2.0.37 kernel,    eth0:(ISA) NE2000, Debian 2.1 (Slink) current with
upgrades.

21:57:07.372776 0:50:54:98:e1:36 0:50:54:98:e1:36 loopback 60:
                         0000 0100 0000 0000 0000 0000 0000 0000
                         0000 0000 0000 0000 0000 0000 0000 0000
                         0000 0000 0000 0000 0000 0000 0000
21:57:17.292800 0:50:54:98:e1:36 0:50:54:98:e1:36 loopback 60:
                         0000 0100 0000 0000 0000 0000 0000 0000
                         0000 0000 0000 0000 0000 0000 0000 0000
                         0000 0000 0000 0000 0000 0000 0000
21:57:27.379243 0:50:54:98:e1:36 0:50:54:98:e1:36 loopback 60:
                         0000 0100 0000 0000 0000 0000 0000 0000
                         0000 0000 0000 0000 0000 0000 0000 0000
                         0000 0000 0000 0000 0000 0000 0000
and on and on every 10 seconds or so.....

I never noticed this before now it concerns me.  I have another, very much
the same box (HW & OS) that does not show this output.

Is this normal or is something amiss?

TIA

Tom