From: Joseph Ezerski (jezerski@xxxxxxxxxxxx)
Date: Thu Apr 11 2002 - 02:27:49 GMT-3
Ok, according to Stevens (TCP/IP Illustrated Vol 1), the ICMP Ping Packet
looks like this:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Identifier | Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Optional Data |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The RFC 792, does not specify a time value, other than IP TTL (at that time,
assumed to be in units of seconds). I think it really depends on how your
OS has implemented it. For example, on my Windows PC, the default timeout
is 2000ms. However, there is an option you can set (-w in the windows
world) to extend that timeout. Stevens mentions something about newer UNIX
implementations (as of the early 90s) timing out after 20 seconds. My
Solaris box times out after 20 s, and it is listed in the man pages as such.
HTH
-Joe
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
Ouellette, Tim
Sent: Wednesday, April 10, 2002 8:13 PM
To: 'cisco@groupstudy.com'; 'ccielab@groupstudy.com'
Subject: Ping times? Am i missing something
The other day while troubleshooting an issue, I saw some pings from out
Tivoli Netview box and it was showing ping times in the 15,000+ ms range. Is
this possible? I though there was a limit on this particular field in the
head. If an of our frame-format experts (Priscilla?) or sniffer gurus
(again... Priscilla?), could point me someone I'd appreciate it. Thanks a
bunch!
This archive was generated by hypermail 2.1.4 : Thu Jun 13 2002 - 10:58:05 GMT-3