On Thu, Sep 10, 2009 at 11:02 AM, John Aldrich
<jaldr...@blueridgecarpet.com> wrote:
> You can also use another form of traceroute that does not use ICMP
AFAIK, all traceroute implementations use and depend on ICMP
(Internet Control Message Protocol). Specifically, the ICMP Time
Expired message that proper Internet Protocol implementations return
when TTL (Time To Live) is exceeded.
However, not all traceroute implementations *send* ICMP messages.
Microsoft's TRACERT sends ICMP Echo Request ("ping") messages to the
specified target. It knows it has reached the target when it gets
ICMP Echo Response instead of Time Exceeded back.
The traditional Unix implementation sends UDP (IIRC) packets. It
knows it has reached the target when it gets ICMP Port Unreachable
instead of ICMP Time Exceeded back. Some have an option (-I) to send
ICMP Echo Request instead.
-- Ben
~ Finally, powerful endpoint security that ISN'T a resource hog! ~
~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~
