Security Basics mailing list archives
RE: traceroute-like tool for UDP or TCP packet
From: "David Gillett" <gillettdavid () fhda edu>
Date: Thu, 21 Aug 2003 16:07:57 -0700
Linux uses UDP packets to traceroute, not ICMP packets like windows does.Not really.... an ICMP packet is a type of UDP packet.
Nope. ICMP and UDP are different protocols on top of IP.
Basicly traceroute works by sending a series of ICMP ECHO requests with increacing TTLs (time to live - how many hops the packet can travel before it dies and aPacket Timeout error is sent).
What kind of packet traceroute sends depends on what the author chose to use. The two most common are UDP echo-request and ICMP echo-request, because the target host should reply with a UDP echo or ICMP echo (respectively) instead of the ICMP time-exceeded which intermediate routers will send when TTL expires.
A ping is also just a ICMP ECHO message, just with a defualt TTL, rather than a series of increasing TTLs.
ICMP echo-request, actually; ICMP echo is the answer coming back. David Gillett --------------------------------------------------------------------------- ----------------------------------------------------------------------------
Current thread:
- Re: traceroute-like tool for UDP or TCP packets some guy (Aug 21)
- Re: traceroute-like tool for UDP or TCP packet Edward Rustin (Aug 21)
- Re: traceroute-like tool for UDP or TCP packet Ranjeet Shetye (Aug 21)
- Re: traceroute-like tool for UDP or TCP packet Ranjeet Shetye (Aug 21)
- RE: traceroute-like tool for UDP or TCP packet David Gillett (Aug 21)
- Re: traceroute-like tool for UDP or TCP packet Ranjeet Shetye (Aug 21)
- <Possible follow-ups>
- Re: traceroute-like tool for UDP or TCP packets A.C. Speelman (Aug 21)
- Re: traceroute-like tool for UDP or TCP packet Edward Rustin (Aug 21)