encounter a strange problem when ping an IP

From: Paul. Vanchope (cuihh6_at_HOTMAIL.COM)
Date: 02/27/04

  • Next message: Damir Delija: "Re: Admins to Boxes ratio" 
    Date:         Thu, 26 Feb 2004 21:55:25 -0500
To: aix-l@Princeton.EDU

    I have configure 2 ip addresses for the host:
    #:/>netstat -in
    Name Mtu Network Address Ipkts Ierrs Opkts Oerrs Coll
    en0 1500 link#2 0.6.29.c3.27.26 9773 0 1629 0
    0
    en0 1500 10.10.176.1 10.10.176.196 9773 0 1629 0
    0
    en3 1500 link#3 0.6.29.c3.a7.78 12068 0 26 0
    0
    en3 1500 10.10.176 10.10.176.101 12068 0 26 0
    0
    lo0 16896 link#1 3635 0 3654 0
    0
    lo0 16896 127 127.0.0.1 3635 0 3654 0
    0
    lo0 16896 ::1 3635 0 3654 0
    0

    #:/>netstat -nr
    Routing tables
    Destination Gateway Flags Refs Use If PMTU Exp
    Groups

    Route Tree for Protocol Family 2 (Internet):
    default 10.10.176.201 UGc 0 0 en0 - -
    10.9.212.29 10.10.176.201 UGHW 5 1512 en0 1500 -
    10.10.176/25 10.10.176.101 U 0 20 en3 - -
    10.10.176.128/25 10.10.176.196 U 3 3578 en0 - -
    127/8 127.0.0.1 U 0 72 lo0 - -

    Route Tree for Protocol Family 24 (Internet v6):
    ::1 ::1 UH 0 0 lo0 16896 -

    I find the following stange problems:
    When i ping 10.10.176.128 from the host, 10.10.176.193 echoes to my ping.
    #:/>ping 10.10.176.128
    PING 10.10.176.128: (10.10.176.128): 56 data bytes
    64 bytes from 10.10.176.193: icmp_seq=0 ttl=255 time=0 ms
    64 bytes from 10.10.176.193: icmp_seq=1 ttl=255 time=0 ms
    64 bytes from 10.10.176.193: icmp_seq=2 ttl=255 time=0 ms
    64 bytes from 10.10.176.193: icmp_seq=3 ttl=255 time=0 ms
    ----10.10.176.128 PING Statistics----
    4 packets transmitted, 4 packets received, 0% packet loss
    round-trip min/avg/max = 0/0/0 ms

     I think that when i ping 10.10.176.128 , 10.10.176.128 should echoes to my
    ping, not 10.10.176.193.

    Why would the problem happened ?
    In addition, when i traceroute to 10.10.176.128, it is still 10.10.176.193
    to which the traceroute ends.
    #:/>traceroute 10.10.176.128
    trying to get source for 10.10.176.128
    source should be 10.10.176.196
    traceroute to 10.10.176.128 (10.10.176.128) from 10.10.176.196
    (10.10.176.196), 30 hops max
    outgoing MTU = 1500
     1 10.10.176.193 (10.10.176.193) 2 ms 0 ms 0 ms

    Thanks in advance.

  • Next message: Damir Delija: "Re: Admins to Boxes ratio"

    Relevant Pages

    • Why some hosts in Internet not prefer to be traceroute-d ?
      ... i.e. not to send a TTL exceeded ICMP packet back to the host. ... like dropping TTL exceeded ICMP packets (dropping such packets in ... I used to traceroute in unprivileged user mode, ... What's the difference between a router and a endpoint host from ...
      (comp.os.linux.networking)
    • Re: Clever firewall rules
      ... For each ping packet they send, ... >> that a host is there (generally you'll just get no response if there's ... > the network is working or if that machine is up ... >> iptables to always reassemble packets before inspecting them. ...
      (Focus-Linux)
    • RE: Ping Scan
      ... Subject: Ping Scan ... these packets can not be response packets to anything originating ... from my network since there IS NO HOST ON X.X.X.X. ... Version: PGP Personal Privacy 6.5.8 ...
      (Incidents)
    • Re: OT: Joy of Tech down?
      ... ping and traceroute output below. ... Ians-MacBook-Pro:~ ian$ ping www.geekculture.com ... 13 packets transmitted, 0 packets received, 100% packet loss ...
      (uk.comp.sys.mac)
    • cant ssh back into 10.242; host seen as Down
      ... PING 10.242: 56 data bytes ... ping: sendto: Host is down ... 10 packets transmitted, 0 packets received, 100% packet loss ...
      (freebsd-questions)
    Loading