Overlap Fragments

[[email protected]]

Ciao ragazzi....
volevo porvi una domanda...
Ho un 837 con versione 12.4(21a) e ho visto nei log del router che ci sono delle righe di questo tipo...

IP_VFR-3-OVERLAP_FRAGMENTS: Dialer0: from the host 219.142.154.205 destined to xx.xx.xx.xx (ho lasciato apposta il mittente :-I).

leggendo sulla doc Cisco, c'e' scritto:

"IP_VFR-3-OVERLAP_FRAGMENTS : [chars]: from the host [IP_address] destined to [IP_address]

Explanation The router has encountered overlap fragments. "Overlap fragment" means that the offset of one fragment overlaps the offset of another fragment. For example, if the offset of the first fragment is 0 and its length is 800, the offset of the second fragments offset must be 800. If the offset of the second fragment is less than 800, the second fragment overlaps the first fragment. This condition might indicate a hostile attack.

Recommended Action Configure a static ACL to prevent further overlap fragments from the sender. "

Ok, allora come configuro questo tipo di ACL?
Grazie a tutti

[andrewp]

access-list 15 deny host 219.142.154.205
access-list 15 permit ip any any

Dialer 0
access-class 15 in

[[email protected]]

access-list 15 deny host 219.142.154.205
access-list 15 permit ip any any

Dialer 0
access-class 15 in

Ciao Andrea...ma cosi' nego solo quell'ip giusto?

[andrewp]

Ciao Andrea...ma cosi' nego solo quell'ip giusto?

Ciao, questo ti indica nella spiegazione:

Codice: Seleziona tutto

Recommended Action Configure a static ACL to prevent further overlap fragments from the sender.

[[email protected]]

Ciao Andrea...ma cosi' nego solo quell'ip giusto?

Ciao, questo ti indica nella spiegazione:

Codice: Seleziona tutto

Recommended Action Configure a static ACL to prevent further overlap fragments from the sender.

Ok, ti ringrazio...
lo applicata sia dulla Dialer 0 che sulla ethernet 0
Ciao