Questions: (1) ethernet (2) dbxtool

[RHBNC]

1. Our site has several makes of machine including Suns, Vaxen, Macs, RMLs
hanging off an E-net (via repeaters) and nobody seems to know how to trace
the cause when the net crashes. (not often, thank goodness!) Software
includes TCP, DECNET and (?) Pink Book. Please does anybody have any
suggestions about diagnostic tools? I'd like to be able to

Collect bad packets & try to identify the source,

Send pulses (or signals) and check the echoes,

not spend too much money.

2. I am having difficulty with  dbxtool  and we dont have its source in
/usr/src/suntool  I'd be much obliged if somebody can send one.  (SUN
3/60, SUN-OS 3.5)).

Mark