[Ninux-Wireless] icmp duplicati

[piuma a piumalab.org]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Salve a tutti,
vi e` mai capitato di pingare un host e in modo random ricevere 2 risposte per
un pacchetto icmp inviato?

# ping 10.52.3.6
[...]
64 bytes from 10.52.3.6: icmp_seq=458 ttl=57 time=21.1 ms
64 bytes from 10.52.3.6: icmp_seq=459 ttl=57 time=21.1 ms
64 bytes from 10.52.3.6: icmp_seq=460 ttl=57 time=21.3 ms
64 bytes from 10.52.3.6: icmp_seq=460 ttl=57 time=21.3 ms (DUP!)
64 bytes from 10.52.3.6: icmp_seq=461 ttl=57 time=20.9 ms

La riga che riporta la dicitura "(DUP!)" indica un pacchetto echo reply
duplicato. Infatti due pacchetti consecutivi riportano lo seq number 460.

Me lo traccia anche traceroute:

14:58:01.699691 IP su-lh-tryconn2-sm.lottomatica.net > 10.52.3.6: ICMP echo
request, id 30219, seq 458, length 64
14:58:01.720860 IP 10.52.3.6 > su-lh-tryconn2-sm.lottomatica.net: ICMP echo
reply, id 30219, seq 458, length 64

14:58:02.699746 IP su-lh-tryconn2-sm.lottomatica.net > 10.52.3.6: ICMP echo requ
est, id 30219, seq 459, length 64
14:58:02.720855 IP 10.52.3.6 > su-lh-tryconn2-sm.lottomatica.net: ICMP echo
reply, id 30219, seq 459, length 64

14:58:03.699795 IP su-lh-tryconn2-sm.lottomatica.net > 10.52.3.6: ICMP echo
request, id 30219, seq 460, length 64
14:58:03.721099 IP 10.52.3.6 > su-lh-tryconn2-sm.lottomatica.net: ICMP echo
reply, id 30219, seq 460, length 64
14:58:03.721149 IP 10.52.3.6 > su-lh-tryconn2-sm.lottomatica.net: ICMP echo
reply, id 30219, seq 460, length 64


Non conosco la configurazione di rete, ma secondo voi come e` possibile una cosa
del genere? Quando si puo` verificare?

- -- 
Il Piuma
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.11 (GNU/Linux)
Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org/

iQEcBAEBAgAGBQJOIF7QAAoJEDSpnBSp0g/YDwkIAJ1QNw6RnuGWPaCtiw1l8Pjr
R51bgplOFCfZll45XRv1eyxs5TomxLo9Pgp1rY4lV5n4czK7t7zgtwHKeMRsOqZa
ODzBW8YnCw7ErPfDN84C2k72o5opo4+iswRm/LUy/XvVYtfIN/vgxWUGVzdFKNmb
KTtRo1TAIl3tTXfvKehbHSn0XDlKJhpTdNZJrXT3XcZaub06vwYSpw1GPrZEx1zA
lIzNhehP23Xa8DHuyNt7mXDuoQW/T3V1Bp6fIucHGcFvs6U9SA6EloDBFDy3mACR
EBe32LyoG6kddZBTJmKsXxWMR4eCWBiT4xRIalxJIZce0B1HvYVbraixFBSz7RQ=
=Cn1j
-----END PGP SIGNATURE-----