Knowing latency without ICMP?

Discussion in 'Linux Networking' started by Apocalypse 2000, Aug 24, 2003.

  1. Is it possible to use TCP pings to know the latency of a host to another
    like a regular ICMP ping would?

    My ISP blocked all ICMP traffic and i need to know the latency of a few
    dedicated server ill be leasing, the problem is that i need to know the
    latency to my ISP users, because they also would be the main target.

    Any other solution to know latency without using ICMP? Taking into
    consideration that i dont yet have access to the dedicated servers.


    Thanks in advance,

    Apocalypse 2000
     
    Apocalypse 2000, Aug 24, 2003
    #1
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  2. Yes. Check out the following application:

    http://www.hping.org/
     
    Lazar Ianakiev, Aug 24, 2003
    #2
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  3. Apocalypse 2000

    Jem Berkes Guest

    Is it possible to use TCP pings to know the latency of a host to another
    Does your ISP block UDP packets as well? You could send UDP packets on a
    round trip and measure how long it takes to hear an echo.
     
    Jem Berkes, Aug 25, 2003
    #3
  4. How do you "send UDP packets on a round trip"?
     
    Floyd Davidson, Aug 25, 2003
    #4
  5. Apocalypse 2000

    Jem Berkes Guest

    Does your ISP block UDP packets as well? You could send UDP packets on
    You would have to have an application on the other end that co-operates. I
    guess such a facility does not exist though... hmm
     
    Jem Berkes, Aug 25, 2003
    #5
  6. Apocalypse 2000

    Nobody Guest

    If I'm reading the IP specification right, the responding host ought to
    set the TTL field of the IP header to 255... if you can get the other side
    to respond (to your TCP "ping" as you say), you ought to be able to
    average 255 - the received TTL's and get a pretty good idea of the number of
    hops between you and the other side. I don't think regular sockets allow
    you access to the IP headers, though, so you might need to write a program
    to fake a TCP packet or two with raw sockets.
     
    Nobody, Aug 26, 2003
    #6
  7. Apocalypse 2000

    Whoever Guest

    UDP echo should be turned off, because of its potential to be used as an
    amplifier as part of a "fraggle" attack (or is it smurf? Whatever!).

    This probably won't help the original poster, but I can't imagine a
    legitimate reason to block ICMP, so I would advise finding another ISP!

    There is probably a web site that will ping the server for you and report
    times. For sure, you could use www.samspade.org and run traceroute to the
    target -- it then shows repsonse times.
     
    Whoever, Aug 26, 2003
    #7
  8. Here is what i used:

    http://www.mainnerve.com/lft/

    - - - - -
    Tracing ______________________________________.

    TTL LFT trace to 216.239.39.99:80/tcp
    1 10.0.0.1 1.0ms
    2 0.0.0.0 49.0ms
    3 0.0.0.0 47.0ms
    4 ISP.host.sanitized.com (0.0.0.0) 47.0ms
    5 ISP2.host.sanitized.com (0.0.0.2) 70.0ms
    6 sl-st20-mia-12-0.sprintlink.net (144.223.244.37) 73.0ms
    7 sl-bb22-orl-14-1.sprintlink.net (144.232.20.14) 77.0ms
    8 sl-bb20-atl-10-2.sprintlink.net (144.232.19.129) 193.0ms
    9 sl-bb21-atl-14-0.sprintlink.net (144.232.12.142) 90.0ms
    10 144.232.8.182 89.0ms
    11 agr3-loopback.Atlanta.cw.net (208.172.66.103) 96.0ms
    12 dcr1-so-0-2-0.Atlanta.cw.net (208.172.75.9) 97.0ms
    13 dcr2-loopback.Washington.cw.net (206.24.226.100) 103.0ms
    14 bhr1-pos-10-0.Sterling1dc2.cw.net (206.24.238.166) 105.0ms
    15 csr12-ve240.Sterling2dc3.cw.net (216.109.66.83) 105.0ms
    16 216.109.88.222 105.0ms
    17 216.239.47.46 107.0ms
    18 [target] 216.239.39.99:80 112.0ms
    - - - - -


    I had to use cygwin to use it in window because i dont have linux in this bo
    x.

    But umap also let you "tcp ping" perfectly fine from ICMP


    There's 100's of reason to block ICMP...and almost none to keep it.


    Thanks guys,

    Apocalypse 2000
     
    Apocalypse 2000, Aug 27, 2003
    #8
  9. Apocalypse 2000

    Jem Berkes Guest

    Here is what i used:
    Very neat! However I still think lft listens for ICMP time exceeded
    messages from routers - if incoming ICMP is blocked by the ISP, I don't
    think this will work.
     
    Jem Berkes, Aug 27, 2003
    #9

  10. Oh yes it works, my ISP has outgoing ICMP blocked, worked for me, i was the
    original poster :p.
     
    Apocalypse 2000, Aug 27, 2003
    #10
  11. Sorry.
    What i ment is that my ISP has ICMP blocked BOTH ways.
    so it works fine without any ICMP.
    umap also works.
     
    Apocalypse 2000, Aug 27, 2003
    #11
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