Frustrated that I don't UNDERSTAND why my network times out

Discussion in 'Linux Networking' started by billy, Oct 8, 2013.

  1. billy

    unruh Guest

    But surely his chain does not take 64 sec to reach the far end (assuming
    I am reading that correctly). That would be absurd. But I guess changing
    that default does not harm much. On the other hand, somewhere down the
    route that ttl could be changed by one of the other links in the chain.
     
    unruh, Oct 10, 2013
    #61
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  2. billy

    billy Guest

    As additional datapoints, my neighbors on the same WISP to run
    the same traceroutes as I did.

    They get through.

    Here are the details from one neighbor, with her IP address
    redacted for privacy.

    NEIGHBOR #1:

    C:\Windows\system32>tracert centos.org

    Tracing route to centos.org [72.232.194.162]
    over a maximum of 30 hops:

    1 <1 ms <1 ms <1 ms REDACTED_IP.ridgewireless.net
    [xx.xx.xx.xx]
    2 3 ms 1 ms 1 ms 10.50.0.1
    3 9 ms 5 ms 31 ms 10.25.0.1
    4 5 ms 11 ms 13 ms 10.20.0.1
    5 33 ms 28 ms 25 ms 10.0.0.1
    6 68 ms 70 ms 62 ms 69.36.226.193
    7 40 ms 13 ms 66 ms vl2.core1.scl.layer42.net
    [69.36.225.129]
    8 14 ms 6 ms 12 ms 216.156.84.141.ptr.us.xo.net
    [216.156.84.141]
    9 86 ms 85 ms 87 ms 207.88.14.233.ptr.us.xo.net
    [207.88.14.233]
    10 81 ms 63 ms 62 ms vb15.rar3.dallas-tx.us.xo.net
    [207.88.12.45]
    11 58 ms 59 ms 60 ms 207.88.14.34.ptr.us.xo.net
    [207.88.14.34]
    12 61 ms 55 ms 99 ms 207.88.185.74.ptr.us.xo.net
    [207.88.185.74]
    13 117 ms 112 ms 65 ms border1.pc2-bbnet2.dal004.pnap.net
    [216.52.191.81]
    14 98 ms 53 ms 54 ms layered-11.border1.dal004.pnap.net
    [63.251.44.74]
    15 * * * Request timed out.
    16 63 ms 54 ms 58 ms www.centos.org [72.232.194.162]

    Trace complete.

    C:\Windows\system32>


    C:\Windows\system32>tracert linuxreference.com

    Tracing route to linuxreference.com [72.232.194.162]
    over a maximum of 30 hops:

    1 <1 ms <1 ms <1 ms REDACTED_IP.ridgewireless.net
    [xx.xx.xx.xx]
    2 7 ms 5 ms 1 ms 10.50.0.1
    3 2 ms 3 ms 2 ms 10.25.0.1
    4 5 ms 5 ms 11 ms 10.20.0.1
    5 38 ms 15 ms 32 ms 10.0.0.1
    6 61 ms 83 ms 86 ms 69.36.226.193
    7 37 ms 80 ms 47 ms vl2.core1.scl.layer42.net
    [69.36.225.129]
    8 15 ms 15 ms 10 ms 216.156.84.141.ptr.us.xo.net
    [216.156.84.141]
    9 84 ms 150 ms 70 ms 207.88.14.233.ptr.us.xo.net
    [207.88.14.233]
    10 132 ms 70 ms 64 ms vb15.rar3.dallas-tx.us.xo.net
    [207.88.12.45]
    11 83 ms 163 ms 124 ms 207.88.14.34.ptr.us.xo.net
    [207.88.14.34]
    12 59 ms 79 ms 91 ms 207.88.185.74.ptr.us.xo.net
    [207.88.185.74]
    13 177 ms * 81 ms border1.pc1-bbnet1.dal004.pnap.net
    [216.52.191.19]
    14 102 ms 84 ms 63 ms layered-11.border1.dal004.pnap.net
    [63.251.44.74]
    15 * * * Request timed out.
    16 52 ms 59 ms 64 ms www.centos.org [72.232.194.162]

    Trace complete.

    C:\Windows\system32>
     
    billy, Oct 10, 2013
    #62
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  3. billy

    billy Guest

    Here are details from a second neighbor, on the same WISP.

    % traceroute www.centos.org
    traceroute to www.centos.org (72.232.194.162), 64 hops max, 52 byte
    packets
    1 192.168.1.1 (192.168.1.1) 1.461 ms 0.955 ms 0.848 ms
    2 IP_REDACTED.ridgewireless.net (xx.xx.xx.xx) 1.584 ms 1.642 ms
    1.191 ms
    3 10.50.0.1 (10.50.0.1) 19.264 ms 15.133 ms 22.613 ms
    4 10.25.0.1 (10.25.0.1) 24.238 ms 11.541 ms 23.235 ms
    5 10.20.0.1 (10.20.0.1) 274.715 ms 175.756 ms 164.049 ms
    6 utm9s (10.0.0.1) 179.232 ms 170.025 ms 112.407 ms
    7 69.36.226.193 (69.36.226.193) 237.651 ms 279.127 ms 131.729 ms
    8 vl2.core1.scl.layer42.net (69.36.225.129) 229.883 ms 212.336 ms
    262.883 ms
    9 216.156.84.141.ptr.us.xo.net (216.156.84.141) 320.652 ms 181.714
    ms 319.745 ms
    10 207.88.14.233.ptr.us.xo.net (207.88.14.233) 410.173 ms 410.476 ms
    314.872 ms
    11 vb15.rar3.dallas-tx.us.xo.net (207.88.12.45) 453.813 ms 297.798
    ms 380.139 ms
    12 207.88.14.34.ptr.us.xo.net (207.88.14.34) 384.894 ms 428.511 ms
    451.605 ms
    13 207.88.185.74.ptr.us.xo.net (207.88.185.74) 384.011 ms 356.507 ms
    290.830 ms
    14 border1.pc1-bbnet1.dal004.pnap.net (216.52.191.19) 445.664 ms
    border1.pc2-bbnet2.dal004.pnap.net (216.52.191.81) 234.716 ms
    258.429 ms
    15 layered-11.border1.dal004.pnap.net (63.251.44.74) 354.172 ms
    445.370 ms 146.977 ms
    16 * * *
    17 www.centos.org (72.232.194.162) 285.244 ms !Z 180.605 ms !Z
    149.697 ms !Z
    %


    Both neighbors make it to Centos.org in about the same number
    of hops that mine fails at.
     
    billy, Oct 10, 2013
    #63
  4. billy

    billy Guest

    This is a great detective idea!

    On Knoppix, my TTL is set, by default, to 64 also:
    $ cat /proc/sys/net/ipv4/ip_default_ttl
    ==> 64
    If I understand it correctly, that's 64 routers, right?
    I only seem to be going through 1/4 that many routers,
    yet, mine fails to complete the route.

    Still, it seems useful to increase the number & try again.
    I can't modify the Knoppix TTL since it's on a DVD so I
    will try it with another operating system and report back.
     
    billy, Oct 10, 2013
    #64
  5. billy

    unruh Guest

    Sure you can. Just as he says. Everything in /proc is a fake filesystem,
    it is NOT on the hard disk or dvd or anything. It is a look into the
    kernel which is of course in memory. Just do as he says.
     
    unruh, Oct 10, 2013
    #65
  6. billy

    ps56k Guest

    Your basic problem in this entire discussion
    is that you have no concept of the very basics in networking -
    called - a protocol stack -

    Here is the TCP/IP version -

    Application (like email, browser, etc)
    Transport (specify ports on computers)
    Internet (addressing & routing)
    Link (physical)

    The browser lives at the very top - as an Application
    and has NO knowledge of ANY protocol issues at the lower layers.
    So, to keep asking about how the fix the browser is meaningless.

    The lower layers are where TCP (Transport Control Protocol)
    and the IP (Internet Protocol) address live.

    Next - is the physical and link.... this is the magic of "transmit" and
    "receive" -

    SO - some routers and website might turn of their responses to ICMP messages
    (ping/echo etc)
    and it might appear they are not responding to those tools - but in fact -
    they are "ignoring" them.

    On the topic of MTU (the size of the packets transmitted)
    I have never had a website not respond,
    but have had probs with a school system called Blackboard
    that would not function properly on a DSL line
    due to a MTU being less than the Blackboard required value of 1500.

    WEIRD -
    I can ping and traceroute to --> centos.org
    but it does NOT reply to my browser request ??

    This page cannot be displayed due to an internal error.

    If you are the administrator of this site, please visit the Xoops
    Troubleshooting Page for assistance.

    Error [Xoops]: Unable to connect to database in file
    class/database/databasefactory.php line 34
     
    ps56k, Oct 10, 2013
    #66
  7. billy

    ps56k Guest

  8. billy

    Mike Easter Guest

    Mike Easter, Oct 10, 2013
    #68
  9. billy

    Mike Easter Guest

    Initiating server query ...
    Looking up IP address for domain: www.centos.org
    The IP address for the domain is: 85.12.30.227
    Connecting to the server on standard HTTP port: 80
    The port is closed, so our connection attempt was refused.
    Query complete.
     
    Mike Easter, Oct 10, 2013
    #69

  10. Does your firewall block ICMP coming from the outside?
    If yes, stop doing that, and research PMTUD.

    Best regards
    Thomas
     
    Thomas Keusch, Oct 10, 2013
    #70
  11. billy

    unruh Guest

    He may not have, but it is irrelevant. He is not able to connect. Can
    you give him the cause? Can you suggest how he fix it? It is like if you
    brought me your car to fix and I told you that you had no concept of the
    basics of the Standard Model of particle phyics as if such knowledge
    would help you fix your car.
    And you now call this weird. I thought you had an intimate knowledge of
    the protocol layers. Why is this weird?

    Note that I have absolutely no trouble connecting to centos.org.
     
    unruh, Oct 10, 2013
    #71
  12. billy

    Chris Davies Guest

    I have.

    Chris
     
    Chris Davies, Oct 11, 2013
    #72
  13. billy

    Chris Davies Guest

    It's not a DNS TTL, it's a hop count. 64 hops is the maximum distance
    packets from my system can reach.

    Each hop decrements the value by one until it hits zero.
    Chris
     
    Chris Davies, Oct 11, 2013
    #73
  14. billy

    Chris Davies Guest

    Yes, which should be plenty.

    Bang goes another theory.

    You can modify the value for the duration of the session because it's
    held in the kernel, in memory.

    Chris
     
    Chris Davies, Oct 11, 2013
    #74
  15. billy

    ps56k Guest

    this is an interesting discussion -
    you mean like -
    please fix my car - the lugnuts don't fit into the key slot - so I can't
    start it -
    "different layers" - but guess I'll just keep throwing tech words around...

    weird - yup -
    it times out from my network - and other "online testing sites" -
    so... ????

    Ping - centos.org - 85.12.30.227 --> Amsterdam
    Ping - www.centos.org - 72.232.194.162 ---> ????

    So, where does the - 72.232.194.162 come from ??
    vs my DNS lookup is showing 85.12.30.227 ??

    2 NS1.LAYEREDTECH.COM 72.232.1.236
    AUTH 0 ms Received 1 Answers , rcode=
    PTR: PointerName=www.centos.org,

    cname:www.centos.org
    Lookup failed after 1 name server timed out or responded non-authoritatively

    -----------
    Here's his traceroute run:
    knoppix@Microknoppix:~$ traceroute www.centos.org
    traceroute to www.centos.org (72.232.194.162), 30 hops max, 60 byte

    ----------
    HopCount IP Address HostName
    1 208.123.79.34 net208-123-79-34.static-customer.corenap.com
    2 198.252.182.180 aus-core-10-v12.corenap.com
    3 24.155.184.106 xe-0-0-2-509.AUSTTXMIM002.aggr09.austtx.grandecom.net
    4 24.155.121.76 xe-0-0-0-0.aggr08.austtx.grandecom.net
    5 4.30.74.53 ae5-868.edge9.Dallas1.Level3.net
    6 4.69.145.200 ae-4-90.edge3.Dallas1.Level3.net
    7 4.71.170.6 LAYERED-TEC.edge3.Dallas1.Level3.net
    8 * * * * * *
    9 72.232.194.162 www.centos.org
     
    ps56k, Oct 11, 2013
    #75
  16. billy

    Thad Floryan Guest

    Here (Silicon Valley over Comcast's High Speed Internet)
    a 'ping centos.org' and a ping 'www.centos.org' both
    resolve to 85.12.30.227

    a 'whois 72.232.194.162' reveals it's Akamai, a worldwide
    service for faster Internet used by all the majors: Google,
    fecebook, etc. per:


    NetRange: 172.224.0.0 - 172.239.255.255
    CIDR: 172.224.0.0/12
    OriginAS:
    NetName: AKAMAI
    NetHandle: NET-172-224-0-0-1
    Parent: NET-172-0-0-0-0
    NetType: Direct Assignment
    RegDate: 2013-03-15
    Updated: 2013-03-15
    Ref: http://whois.arin.net/rest/net/NET-172-224-0-0-1

    OrgName: Akamai Technologies, Inc.
    OrgId: AT-80
    Address: 8 Cambridge Center
    Address: MS 926-G
    City: Cambridge
    StateProv: MA
    PostalCode: 02142
    Country: US
    RegDate: 2011-10-19
    Updated: 2012-01-26
    Ref: http://whois.arin.net/rest/org/AT-80

    OrgAbuseHandle: MHA379-ARIN
    OrgAbuseName: Hannigan, Martin
    OrgAbusePhone: +1-617-444-2535
    OrgAbuseEmail:
    OrgAbuseRef: http://whois.arin.net/rest/poc/MHA379-ARIN

    OrgTechHandle: MHA379-ARIN
    OrgTechName: Hannigan, Martin
    OrgTechPhone: +1-617-444-2535
    OrgTechEmail:
    OrgTechRef: http://whois.arin.net/rest/poc/MHA379-ARIN
     
    Thad Floryan, Oct 11, 2013
    #76
  17. billy

    billy Guest

    A fortuituous circumstance has occurred.
    I can now connect to centos.org, via the web, ping, traceroute, etc!
    I do NOT know what changed.
    Here's what happened in the interim:
    1. I wrote to the related sysadmins (I did not receive a response)
    2. I changed my MTU (but it made no difference)
    3. I changed machines (Win7, Centos, & Knoppix) which made no difference
    4. I changed the TTL which also made no difference

    Yet, look below. The route is completely different!
    # ping www.centos.org
    PING www.centos.org (85.12.30.227) 56(84) bytes of data.
    64 bytes from 85.12.30.227: icmp_req=1 ttl=44 time=236 ms
    64 bytes from 85.12.30.227: icmp_req=2 ttl=44 time=165 ms
    64 bytes from 85.12.30.227: icmp_req=3 ttl=44 time=164 ms
    64 bytes from 85.12.30.227: icmp_req=4 ttl=44 time=169 ms
    64 bytes from 85.12.30.227: icmp_req=5 ttl=44 time=180 ms
    ^C
    --- www.centos.org ping statistics ---
    6 packets transmitted, 5 received, 16% packet loss, time 5043ms
    rtt min/avg/max/mdev = 164.682/183.212/236.535/27.238 ms

    # telnet www.centos.org 80
    Trying 85.12.30.227...
    Connected to www.centos.org.
    Escape character is '^]'.
    HEAD / HTTP/1.0

    HTTP/1.1 200 OK
    Server: nginx/0.8.55
    Date: Fri, 11 Oct 2013 00:45:11 GMT
    Content-Type: text/html; charset=ISO-8859-1
    Connection: close
    X-Powered-By: PHP/4.3.9
    Set-Cookie: PHPSESSID=2170e308a49222dbe637c509e5c60702; path=/
    Expires: Mon, 26 Jul 1997 05:00:00 GMT
    Cache-Control: private, no-cache
    Pragma: no-cache

    Connection closed by foreign host.


    # traceroute -M icmp www.centos.org
    traceroute to www.centos.org (85.12.30.227), 30 hops max, 60 byte packets
    1 192.168.1.1 (192.168.1.1) 2.834 ms 2.827 ms 2.831 ms
    2 67-218-118-85.ridgewireless.net (67.218.118.85) 2.836 ms 2.834 ms 5.724 ms
    3 10.50.0.1 (10.50.0.1) 9.067 ms 17.504 ms 17.501 ms
    4 10.25.0.1 (10.25.0.1) 17.497 ms 24.062 ms 24.060 ms
    5 10.20.0.1 (10.20.0.1) 33.210 ms 33.209 ms 33.207 ms
    6 10.0.0.1 (10.0.0.1) 42.110 ms 27.157 ms 95.411 ms
    7 69.36.226.193 (69.36.226.193) 126.784 ms 17.564 ms 83.245 ms
    8 vl2.core2.scl.layer42.net (69.36.225.130) 83.220 ms 25.765 ms 75.471 ms
    9 xe-0-0-0-22.r07.snjsca04.us.bb.gin.ntt.net (140.174.21.101) 92.593 ms 17.517 ms 57.495 ms
    10 te0-4-0-32.ccr21.sjc03.atlas.cogentco.com (154.54.10.49) 61.049 ms te0-7-0-32.ccr21.sjc03.atlas.cogentco.com (154.54.11.85)
    50.591 ms 98.951 ms
    11 be2000.ccr21.sjc01.atlas.cogentco.com (154.54.6.105) 101.595 ms be2047.ccr22.sjc01.atlas.cogentco.com (154.54.5.113)
    25.443 ms be2000.ccr21.sjc01.atlas.cogentco.com (154.54.6.105) 31.126 ms
    12 be2164.ccr21.sfo01.atlas.cogentco.com (154.54.28.33) 31.098 ms be2167.mpd22.sfo01.atlas.cogentco.com (154.54.28.77) 23.081
    ms be2164.ccr21.sfo01.atlas.cogentco.com (154.54.28.33) 106.955 ms
    13 be2132.ccr21.mci01.atlas.cogentco.com (154.54.30.54) 121.000 ms be2135.mpd22.mci01.atlas.cogentco.com (154.54.6.34)
    125.153 ms be2132.ccr21.mci01.atlas.cogentco.com (154.54.30.54) 125.125 ms
    14 be2156.ccr21.ord01.atlas.cogentco.com (154.54.6.86) 125.095 ms be2159.mpd22.ord01.atlas.cogentco.com (154.54.24.82) 98.844
    ms be2156.ccr21.ord01.atlas.cogentco.com (154.54.6.86) 98.816 ms
    15 be2079.ccr21.yyz02.atlas.cogentco.com (154.54.27.182) 108.449 ms 104.541 ms be2140.ccr22.bos01.atlas.cogentco.com
    (154.54.43.186) 118.863 ms
    16 be2091.ccr22.ymq02.atlas.cogentco.com (154.54.44.98) 118.831 ms be2090.ccr21.ymq02.atlas.cogentco.com (154.54.30.206)
    105.995 ms te0-1-0-1.ccr22.lpl01.atlas.cogentco.com (154.54.42.106) 173.380 ms
    17 te0-5-0-6.ccr22.lpl01.atlas.cogentco.com (154.54.87.57) 165.254 ms be2183.ccr22.ams03.atlas.cogentco.com (154.54.58.70)
    181.351 ms te0-4-0-6.ccr21.lpl01.atlas.cogentco.com (154.54.44.202) 191.954 ms
    18 be2183.ccr22.ams03.atlas.cogentco.com (154.54.58.70) 203.543 ms te0-3-0-12.mag21.ams03.atlas.cogentco.com (154.54.78.213)
    176.249 ms be2183.ccr22.ams03.atlas.cogentco.com (154.54.58.70) 179.087 ms
    19 10ge-2-3.cr1.ams3.baseip.com (149.6.128.198) 182.827 ms te0-3-0-12.mag21.ams03.atlas.cogentco.com (154.54.78.213) 179.250
    ms 10ge-2-3.cr1.ams3.baseip.com (149.6.128.198) 193.421 ms
    20 10ge-2-3.cr1.ams3.baseip.com (149.6.128.198) 176.902 ms 85.12.30.227 (85.12.30.227) 164.817 ms
    10ge-2-3.cr1.ams3.baseip.com (149.6.128.198) 217.757 ms

    I'm not sure why the traaceroute is much longer, and, it stopped
    before Centos.org, but, the proof is in the taste of the pudding
    in that a Firefox connection to http://www.centos.org works all
    of a sudden.

    Q: What changed?
     
    billy, Oct 11, 2013
    #77
  18. billy

    billy Guest

    I'm not sure what changed, but, now I can reach Centos.org!

    I'm also not sure what the bangX is (!X), but, I can now easily
    connect to Centos.org.

    I don't think I permanently changed anything.
    This trace below, for example, is on Knoppix, after a fresh
    reboot, so, none of the TTL changes would take effect:

    $ su root
    # cat /proc/sys/net/ipv4/ip_default_ttl
    ==> 64

    # ifconfig wlan0 | grep MTU
    ==> UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1

    $ traceroute www.centos.org
    traceroute to www.centos.org (85.12.30.227), 30 hops max, 60 byte packets
    1 192.168.1.1 (192.168.1.1) 2.833 ms 2.808 ms 4.232 ms
    2 67-218-118-85.ridgewireless.net (67.218.118.85) 24.856 ms 24.843 ms 24.827 ms
    3 10.50.0.1 (10.50.0.1) 31.589 ms 31.571 ms 31.555 ms
    4 10.25.0.1 (10.25.0.1) 38.395 ms 38.382 ms 38.368 ms
    5 10.20.0.1 (10.20.0.1) 459.405 ms 459.371 ms 459.358 ms
    6 10.0.0.1 (10.0.0.1) 478.430 ms 122.002 ms 121.984 ms
    7 69.36.226.193 (69.36.226.193) 128.186 ms 128.170 ms 128.155 ms
    8 vl2.core2.scl.layer42.net (69.36.225.130) 144.227 ms 144.216 ms 144.201 ms
    9 xe-0-0-0-22.r07.snjsca04.us.bb.gin.ntt.net (140.174.21.101) 128.082 ms 128.058 ms 128.042 ms
    10 te0-7-0-32.ccr21.sjc03.atlas.cogentco.com (154.54.11.85) 128.026 ms 128.012 ms 128.006 ms
    11 be2047.ccr22.sjc01.atlas.cogentco.com (154.54.5.113) 127.980 ms be2000.ccr21.sjc01.atlas.cogentco.com (154.54.6.105) 127.964
    ms 182.368 ms
    12 be2167.mpd22.sfo01.atlas.cogentco.com (154.54.28.77) 182.351 ms be2164.ccr21.sfo01.atlas.cogentco.com (154.54.28.33) 142.475
    ms 198.711 ms
    13 be2135.mpd22.mci01.atlas.cogentco.com (154.54.6.34) 239.809 ms be2134.mpd21.mci01.atlas.cogentco.com (154.54.6.38) 239.778 ms
    be2135.mpd22.mci01.atlas.cogentco.com (154.54.6.34) 239.767 ms
    14 be2157.ccr22.ord01.atlas.cogentco.com (154.54.6.118) 251.841 ms 251.817 ms be2158.mpd21.ord01.atlas.cogentco.com
    (154.54.7.130) 251.807 ms
    15 be2080.ccr22.yyz02.atlas.cogentco.com (154.54.42.6) 267.756 ms be2081.ccr21.yyz02.atlas.cogentco.com (154.54.42.10) 267.730 ms
    be2140.ccr22.bos01.atlas.cogentco.com (154.54.43.186) 267.722 ms
    16 te0-4-0-1.ccr21.lpl01.atlas.cogentco.com (154.54.44.198) 322.941 ms te0-2-0-1.ccr22.lpl01.atlas.cogentco.com (154.54.0.210)
    322.907 ms be2092.ccr21.ymq02.atlas.cogentco.com (154.54.25.26) 142.921 ms
    17 be2184.mpd21.ams03.atlas.cogentco.com (154.54.37.69) 322.880 ms 322.865 ms be2185.mpd22.ams03.atlas.cogentco.com
    (154.54.37.105) 339.005 ms
    18 te0-3-0-3.mag21.ams03.atlas.cogentco.com (154.54.78.210) 338.983 ms be2183.ccr22.ams03.atlas.cogentco.com (154.54.58.70)
    338.955 ms te0-7-0-12.mag21.ams03.atlas.cogentco.com (154.54.76.202) 338.947 ms
    19 te0-7-0-18.mag21.ams03.atlas.cogentco.com (154.54.76.213) 338.936 ms te0-7-0-6.mag21.ams03.atlas.cogentco.com (154.54.76.198)
    338.912 ms te0-7-0-4.mag21.ams03.atlas.cogentco.com (154.54.76.138) 338.873 ms
    20 10ge-2-3.cr1.ams3.baseip.com (149.6.128.198) 335.208 ms 338.830 ms 338.806 ms
    21 85.12.30.227 (85.12.30.227) 335.141 ms !X 229.087 ms !X 229.051 ms !X

    # telnet www.centos.org 80
    Trying 85.12.30.227...
    Connected to www.centos.org.
    Escape character is '^]'.
    HEAD / HTTP/1.0

    HTTP/1.1 200 OK
    Server: nginx/0.8.55
    Date: Fri, 11 Oct 2013 01:02:27 GMT
    Content-Type: text/html; charset=ISO-8859-1
    Connection: close
    X-Powered-By: PHP/4.3.9
    Set-Cookie: PHPSESSID=077a08159b3f653d8b2322a77f34806c; path=/
    Expires: Mon, 26 Jul 1997 05:00:00 GMT
    Cache-Control: private, no-cache
    Pragma: no-cache

    Connection closed by foreign host.

    # ping www.centos.org
    PING www.centos.org (85.12.30.227) 56(84) bytes of data.
    64 bytes from 85.12.30.227: icmp_req=1 ttl=44 time=182 ms
    64 bytes from 85.12.30.227: icmp_req=2 ttl=44 time=267 ms
    ^C
    --- www.centos.org ping statistics ---
    2 packets transmitted, 2 received, 0% packet loss, time 1008ms
    rtt min/avg/max/mdev = 182.493/224.922/267.351/42.429 ms
    root@Microknoppix:~# ping centos.org
    PING centos.org (85.12.30.227) 56(84) bytes of data.
    64 bytes from 85.12.30.227: icmp_req=1 ttl=44 time=187 ms
    64 bytes from 85.12.30.227: icmp_req=2 ttl=44 time=162 ms
    64 bytes from 85.12.30.227: icmp_req=3 ttl=44 time=179 ms
    64 bytes from 85.12.30.227: icmp_req=4 ttl=44 time=235 ms
    ^C
    --- centos.org ping statistics ---
    4 packets transmitted, 4 received, 0% packet loss, time 3019ms
    rtt min/avg/max/mdev = 162.922/191.276/235.687/27.093 ms
     
    billy, Oct 11, 2013
    #78
  19. billy

    billy Guest

    But, interestingly, I still can not reach linuxreference.com.

    Note: This site is meaningless to me, so, it's just of interest
    but it has no practical significance since it's not a site
    I often rely upon.

    But, here is the trace, with centos.org working, linuxreference.com
    does not.


    # traceroute -M icmp linuxreference.com
    traceroute to linuxreference.com (72.232.194.162), 30 hops max, 60 byte
    packets
    1 192.168.1.1 (192.168.1.1) 3.642 ms 3.637 ms *
    2 * * *
    3 * * *
    4 * * *
    5 * * *
    6 * 10.0.0.1 (10.0.0.1) 131.604 ms 131.542 ms
    7 69.36.226.193 (69.36.226.193) 131.534 ms 131.531 ms 131.533 ms
    8 vl2.core1.scl.layer42.net (69.36.225.129) 131.519 ms 131.520 ms
    131.517 ms
    9 216.156.84.141.ptr.us.xo.net (216.156.84.141) 131.514 ms 131.509 ms
    131.506 ms
    10 207.88.14.233.ptr.us.xo.net (207.88.14.233) 331.912 ms 329.009 ms
    334.690 ms
    11 vb15.rar3.dallas-tx.us.xo.net (207.88.12.45) 331.876 ms 331.874 ms
    124.878 ms
    12 207.88.14.34.ptr.us.xo.net (207.88.14.34) 118.154 ms 149.195 ms
    188.104 ms
    13 207.88.185.74.ptr.us.xo.net (207.88.185.74) 188.093 ms 173.788 ms
    173.766 ms
    14 border1.pc2-bbnet2.dal004.pnap.net (216.52.191.81) 173.749 ms
    border1.pc1-bbnet1.dal004.pnap.net (216.52.191.19) 68.081 ms 138.710 ms
    15 layered-11.border1.dal004.pnap.net (63.251.44.74) 155.481 ms 155.470
    ms 155.461 ms
    16 * * *
    17 * * *
    18 * * *
    19 * * *
    20 * * *
    21 * * *
    22 * * *
    23 * * *
    24 * * *
    25 * * *
    26 * * *
    27 * * *
    28 * * *
    29 * * *
    30 * * *
     
    billy, Oct 11, 2013
    #79
  20. billy

    billy Guest

    Ah, I see what I did wrong.

    I had tried to edit the file in vi but I got a "Fsync failed"
    red-text error using 'vi' on that file as root in Knoppix:

    knoppix@Microknoppix:~$ su root
    root@Microknoppix:/home/knoppix# cd /proc/sys/net/ipv4
    root@Microknoppix:/proc/sys/net/ipv4# cat ip_default_ttl
    64
    root@Microknoppix:/proc/sys/net/ipv4# vi !$
    vi ip_default_ttl
    (here I changed the 64 to 128)
    (then I hit wq!)
    (and got the error below)
    "ip_default_ttl"
    "ip_default_ttl" E667: Fsync failed
    Press ENTER or type command to continue
    # cat ip_default_ttl
    64

    But, simply echoing to the file DOES change it!
    root@Microknoppix:/proc/sys/net/ipv4# echo "128" > ip_default_ttl
    root@Microknoppix:/proc/sys/net/ipv4# cat ip_default_ttl
    128

    So, you were right!
    My mistake.
     
    billy, Oct 11, 2013
    #80
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