From: Becky Qiang (becky.qiang@wincomsystems.com)
Date: Wed Sep 11 2002 - 22:03:53 GMT-3
Guys:
It may also clearify several things just by reading the first three four
pages of this URL link to IETF.org. It tells about the IETF standard for
both PING and TRACEROUTE. But Cisco and Microsoft always have their own home
grown thing as usual. :-)
http://www.ietf.org/rfc/rfc2925.txt?number=2925
Excerpt:
"Ping and traceroute are two very useful functions for managing
networks. Ping is typically used to determine if a path exists
between two hosts while traceroute shows an actual path. Ping is
usually implemented using the Internet Control Message Protocol
(ICMP) "ECHO" facility. It is also possible to implement a ping
capability using alternate methods, some of which are:
o Using the UDP echo port (7), if supported.This is defined by RFC 862
[2].
o Timing an SNMP query.
o Timing a TCP connect attempt.
Traceroute is usually implemented by transmitting a series of probe
packets with increasing time-to-live values. A probe packet is a UDP
datagram encapsulated into an IP packet. Each hop in a path to the
target (destination) host rejects the probe packet (probe's TTL too
small) until its time-to-live value becomes large enough for the
probe to be forwarded. Each hop in a traceroute path returns an ICMP
message that is used to discover the hop and to calculate a round
trip time. Some systems use ICMP probes (ICMP Echo request packets)
instead of UDP ones to implement traceroute. In both cases
traceroute relies on the probes being rejected via an ICMP message to
discover the hops taken along a path to the final destination. Both
probe types, UDP and ICMP, are encapsulated into an IP packet and
thus have a TTL field that can be used to cause a path rejection.
Implementations of the remote traceroute capability as defined within
this memo SHOULD be done using UDP packets to a (hopefully) unused
port. ICMP probes (ICMP Echo Request packets) SHOULD NOT be used.
Many PC implementations of traceroute use the ICMP probe method,
which they should not, since this implementation method has been
known to have a high probability of failure. Intermediate hops
become invisible when a router either refuses to send an ICMP TTL
expired message in response to an incoming ICMP packet or simply
tosses ICMP echo requests altogether.
"
Becky
----- Original Message -----
From: "Brian Dennis" <brian@5g.net>
To: <ccielab@groupstudy.com>
Sent: Wednesday, September 11, 2002 12:44 PM
Subject: RE: non-ICMP ping and non-ICMP traceroute
> The confusion is with traceroute because it's implemented differently by
> different OS's. As I stated Cisco sends UDP packets. Microsoft's
> implementation of traceroute sends ICMP packets.
>
> Brian Dennis, CCIE #2210 (R&S/ISP Dial)
>
> -----Original Message-----
> From: George Bekmezian [mailto:george@bekmezian.com]
> Sent: Wednesday, September 11, 2002 12:24 PM
> To: 'Brian Dennis'; 'Becky Qiang'; ccielab@groupstudy.com
> Subject: RE: non-ICMP ping and non-ICMP traceroute
>
> Looks to me like pings use ICMP and traces use UDP.
>
> |-----Original Message-----
> |From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On
> |Behalf Of Brian Dennis
> |Sent: Wednesday, September 11, 2002 11:54 AM
> |To: 'Becky Qiang'; ccielab@groupstudy.com
> |Subject: RE: non-ICMP ping and non-ICMP traceroute
> |
> |
> |Cisco's implementation of traceroute (IOS and CatOS) is not
> |based on sending ICMP packets. It's based on sending UDP packets.
> |
> |Brian Dennis, CCIE #2210 (R&S/ISP Dial)
> |
> |-----Original Message-----
> |From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On
> |Behalf Of Becky Qiang
> |Sent: Wednesday, September 11, 2002 11:05 AM
> |To: Ravi Chandran; ccielab@groupstudy.com
> |Subject: Re: non-ICMP ping and non-ICMP traceroute
> |
> |I've heard of such thing. Both ping and traceroute command in
> |Cisco CLI are developed based on ICMP...Becky
> |
> |
> |----- Original Message -----
> |From: "Ravi Chandran" <s_ravichandran@hotmail.com>
> |To: <ccielab@groupstudy.com>
> |Sent: Wednesday, September 11, 2002 9:09 AM
> |Subject: non-ICMP ping and non-ICMP traceroute
> |
> |
> |> Hi everyone,
> |>
> |> While in a telenet session on a Cisco switch, can I generate a
> |non-ICMP
> |> ping and non-ICMP traceroute from the command line?
> |>
> |>
> |>
> |> Thanks.
> |>
> |> Ravi
> |>
> |>
> |---------------------------------------------------------------
> |---------
> |>
> |> Join the worlds largest e-mail service with MSN Hotmail. Click Here
> |
This archive was generated by hypermail 2.1.4 : Mon Oct 07 2002 - 07:43:49 GMT-3