Subject: bin/7083: weird errors by ping(1) when using high packetsizes
To: None <gnats-bugs@gnats.netbsd.org>
From: Harold Gutch <logix@sol-r.franken.de>
List: netbsd-bugs
Date: 03/04/1999 15:38:22
>Number:         7083
>Category:       bin
>Synopsis:       weird errors by ping(1) when using high packetsizes
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    bin-bug-people (Utility Bug People)
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Mar  4 06:50:01 1999
>Last-Modified:
>Originator:     Harold Gutch
>Organization:
>Release:        1.3.2
>Environment:
>Description:
	ping behaves strange if you specify a packetsize of 61353
	  bytes or more:

	- for packetsizes up to 61352 it behaves as expected

	- for a packetsize from 61353 up to 61396 it
	  a) claims that it only received a single reply down at the
	     "summary output"
	  b) does not exit for a couple of seconds when you press ^C

	  This only applies when pinging localhost, pinging other
	  machines works as expected. 

	- for a packetsize from 61397 up to 61412 bytes it claims not to
	  have received any replies
	
	- for a packetsize from 61413 bytes up to 65465 bytes, you will
	  experience sendto() errors

	- and finally ping will work again for packetsizes above 65466
	  bytes, as it itself catches the too high sizes.


	This does not seem to be a kernel-problem, as tcpdump shows
	either no packetflow at all (for values higher than 61413
	bytes) or both, the ICMP echo request and the ICMP echo reply.

>How-To-Repeat:
	ping -s <value> localhost

	where <value> is in the range of 61353-65466

>Fix:
	none known
>Audit-Trail:
>Unformatted:
>eNvironment:
System: NetBSD sol-r.franken.de 1.3.2 NetBSD 1.3.2 (SOL-R) #1: Mon Jan 4 17:39:13 CET 1999 logix@sol-r.franken.de:/usr/src/sys/arch/sparc/compile/SOL-R sparc