Traffic UDP bizarre

Bonjour,

Mon IP est bombardée de paquets UDP (une douzaine par seconde).
Analysés par un sniffer, je vois que deux types de paquets arrivent en
alternance en provenance des IP 195.190.137.160 (ou 163,166 et 168)

>IP header
> Version: 4
> Header length: 5 (20 bytes)
> Type of service: 0
> 000..... (Routine)
> ...0.... (Normal delay)
> ....0... (Normal throughput)
> .....0.. (Normal relibility)
> Total length: 185 bytes
> Identification: 19171
> Flags
> DF .1...... (Don't fragment)
> MF ..0..... (Last fragment)
> Fragment offset: 185
> Time to live: 57 hops (seconds)
> Protocol: 0x11 UDP
> Header checksum: 0xE06C (Valid)
> Source IP: 195.190.137.163
> Destination IP: 82.66.117.135
>UDP header
> Source port: 49533
> Destination port: 38838
> Length: 59728 bytes
> Header corrupted

et

>IP header
> Version: 4
> Header length: 5 (20 bytes)
> Type of service: 0
> 000..... (Routine)
> ...0.... (Normal delay)
> ....0... (Normal throughput)
> .....0.. (Normal relibility)
> Total length: 1500 bytes
> Identification: 19171
> Flags
> DF .1...... (Don't fragment)
> MF ..1..... (More fragments)
> Fragment offset: 0
> Time to live: 57 hops (seconds)
> Protocol: 0x11 UDP
> Header checksum: 0xBC02 (Valid)
> Source IP: 195.190.137.163
> Destination IP: 82.66.117.135
>UDP header
> Source port: 53825
> Destination port: 1272
> Length: 1645 bytes
> Header corrupted

Les ports sources et destination changent tout le temps. Aucun moyen
de faire logger ces paquets par mon pare-feu (Kerio), je ne comprends
pas pourquoi. Par contre, mon ordinateur répond par des "destination
unreachable", qui sont bloqués par Kerio (peut-être une mauvaise idée?
C'est une règle par défaut de Kerio):

>1,[13/Dec/2003 12:23:11] Rule 'Other ICMP': Blocked: Out ICMP [3] Destination Unreachable, localhost->(null) [195.190.137.160], Owner: Tcpip Kernel Driver
>1,[13/Dec/2003 12:23:11] Rule 'Other ICMP': Blocked: Out ICMP [3] Destination Unreachable, localhost->(null) [195.190.137.168], Owner: Tcpip Kernel Driver
>1,[13/Dec/2003 12:23:11] Rule 'Other ICMP': Blocked: Out ICMP [3] Destination Unreachable, localhost->(null) [195.190.137.163], Owner: Tcpip Kernel Driver
>1,[13/Dec/2003 12:23:11] Rule 'Other ICMP': Blocked: Out ICMP [3] Destination Unreachable, localhost->(null) [195.190.137.163], Owner: Tcpip Kernel Driver
>1,[13/Dec/2003 12:23:11] Rule 'Other ICMP': Blocked: Out ICMP [3] Destination Unreachable, localhost->(null) [195.190.137.166], Owner: Tcpip Kernel Driver
>1,[13/Dec/2003 12:23:11] Rule 'Other ICMP': Blocked: Out ICMP [3] Destination Unreachable, localhost->(null) [195.190.137.160], Owner: Tcpip Kernel Driver
>1,[13/Dec/2003 12:23:11] Rule 'Other ICMP': Blocked: Out ICMP [3] Destination Unreachable, localhost->(null) [195.190.137.168], Owner: Tcpip Kernel Driver
>1,[13/Dec/2003 12:23:11] Rule 'Other ICMP': Blocked: Out ICMP [3] Destination Unreachable, localhost->(null) [195.190.137.163], Owner: Tcpip Kernel Driver
>1,[13/Dec/2003 12:23:11] Rule 'Other ICMP': Blocked: Out ICMP [3] Destination Unreachable, localhost->(null) [195.190.137.163], Owner: Tcpip Kernel Driver

Ça ne cesse pas, même si je reboote l'ordinateur (WinXP + Freebox).
Mais que me veut-on?

Merci de vos lumières.