[comp.dcom.sys.cisco] Debug woes, hoped for fixes

asteiner@casbah.acns.nwu.edu (Albert Steiner) (10/25/90)

Just when our busy network is acting strangly, we use DEBUG RIP
and find that our communication with the box grinds to a halt, 
eventually we get logged off--timed out.  We can't get back in because
we time out before we can enter passwords etc.

Calling CISCO tells us this is a know "feature".  DEBUG has a higher
priority than almost anything.  DEBUG should not be used on a busy
production system.

The problem is, thats when we want to see the incomming rip packets.
I know Sniffers exist, but I would like to be able to quickly check the 
state of different networks from my desk.  In particular DEBUG IP RIP
has been very useful in other situations.

I think CISCO should allow DEBUG in production, especially of the routing
information.  It is not enough to SHOW Routes, (although that is very useful).
By default DEBUG should turn off after a short time (2 or 3 minutes) or
after some limit such as buffer limits are hit, or after 500 lines of 
output or some such definable termination condition.  DEBUG is especially
useful for production environments, and a CISCO almost works, this kind of
change would be exceedingly useful.

Albert Steiner
Northwestern University
Evanston, IL      Albert_Steiner@NWU.EDU

BILLW@mathom.cisco.com (WilliamChops Westfield) (10/28/90)

    Calling CISCO tells us this is a know "feature".  DEBUG has a higher
    priority than almost anything.  DEBUG should not be used on a busy
    production system.

Actuallty, it is not debugging itself that has such high priority - it
is the output of this debugging information to the console terminal.


    I think CISCO should allow DEBUG in production, especially of the
    routing information.  By default DEBUG should turn off after a short
    time (2 or 3 minutes) or after some limit such as buffer limits are
    hit, or after 500 lines of output or some such definable termination
    condition.

There are a couple of things you can do within the current architecture
that do essentially what you are asking for.  The key is to prevent the
debug output from being sent to the console.  One way to do this is to
explicitly disable logging to the console ("no logging console" config
command), and instead pick up the output on a tcp vty with "terminal
monitor" turned on.  The other way is to configure the system with the
"logging buffered" command, which saves the debugging output in a buffers,
and displays it when you do a "show logging" command.

Note that either of the methods may result in lost debugging messages,
which can be very confusing.

Bill Westfield
cisco Systems.
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