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Session Report

Summary:
Test run at: 2026-04-16 11:33:44 GMT
Client Prefix (v4): 41.66.119.x/24
Client AS (v4): 51265 (MASSRESPONSE-AS2)
IPv4 Probes: 162
Client Prefix (v6): 2a04:9546:1fxx::/40
Client AS (v6): 51265 (MASSRESPONSE-AS2)
IPv6 Probes: 180
Outbound spoofing summary (from the client to our server)
Source address type IPv4IPv6
Private - RFC1918 or ULA blockedunknown
Routable blockedunknown
Largest spoofable neighbor prefix length nonenone
Spoof status key
receivedSpoofed packet was received.Pattern of tests from this IP block indicates a switch from allowing spoofing to blocking it.
rewrittenSpoofed packet was received, but the source address was changed en route.
blockedSpoofed packet was not received, but unspoofed packet was.
unknownNeither spoofed nor unspoofed packet was received.
IPv4 AS Route:
This test run probed the following paths in order to infer your ability to send different spoofed source packets. Each node in the graph corresponds to an autonomous system, i.e. different Internet service providers. NOTE: This graph does NOT show if an AS blocks spoofed packets, only the path taken by received spoofed packets. The IP Path Details are available for this run. If non-spoofed packets weren't received at a destination, the traceroute to that destination is not included in this graph and may even cause a totally empty graph.

  

  

IPv4 Adjacent Netblock Testing:

Your host (41.66.119.x/24) can spoof 0 neighboring addresses


Spoofed source address (anon)Prefix
Length
ASN of spoofed
source address
Received
41.66.119.x/24/3151265natblock
41.66.119.x/24/3051265natblock
41.66.119.x/24/2951265natblock
41.66.119.x/24/2851265natblock
41.66.119.x/24/2751265natblock
41.66.119.x/24/2651265natblock
41.66.119.x/24/2551265natblock
41.66.119.x/24/2451265natblock
41.66.118.x/24/2351265natblock
41.66.117.x/24/2251265natblock
41.66.115.x/24/2151265natblock
41.66.127.x/24/2051265natblock
41.66.103.x/24/1951265natblock
41.66.87.x/24/1851265natblock
41.66.55.x/24/1729571natblock
41.66.247.x/24/1629614natblock
41.67.119.x/24/1536974natblock
41.64.119.x/24/1436992natblock
41.70.119.x/24/1337215natblock
41.74.119.x/24/12327771natblock
41.82.119.x/24/118346natblock
41.98.119.x/24/1036947natblock
41.2.119.x/24/9UNROUTEDnatblock
41.194.119.x/24/822351natblock

Meaning of status in Received column:

natblockSpoofed probe packets appear to be blocked by your local NAT or firewall rather than being rewritten with a public source address.

IPv4 Outbound Filtering Depth:

The tracefilter test found your host unable to spoof routable, non-adjacent source addresses through even the first IP hop.
IPv6 AS Route:
This test run probed the following paths in order to infer your ability to send different spoofed source packets. Each node in the graph corresponds to an autonomous system, i.e. different Internet service providers. NOTE: This graph does NOT show if an AS blocks spoofed packets, only the path taken by received spoofed packets. The IP Path Details are available for this run. If non-spoofed packets weren't received at a destination, the traceroute to that destination is not included in this graph and may even cause a totally empty graph.

  

  
IPv6 Adjacent Netblock Testing:
Spoofed source address (anon)Prefix
Length
ASN of spoofed
source address
Received
2a04:9546:1fxx::/40/12051265no
2a04:9546:1fxx::/40/11251265no
2a04:9546:1fxx::/40/10451265no
2a04:9546:1fxx::/40/9651265no
2a04:9546:1fxx::/40/8851265no
2a04:9546:1fxx::/40/8051265no
2a04:9546:1fxx::/40/7251265no
2a04:9546:1fxx::/40/6451265no
2a04:9546:1fxx::/40/5651265no
2a04:9546:1fxx::/40/4851265no
2a04:9546:1fxx::/40/4051265no
2a04:9546:9fxx::/40/3251265no
2a04:95c6:1fxx::/40/2429611no
2a04:1546:1fxx::/40/16UNROUTEDno

Meaning of status in Received column:

noPackets spoofed from adjacent netblock were not received, probably due to blocking
Summary:
The results from all tests are aggregated to produce a summary "State of IP Spoofing" report.
Feedback:
We welcome questions and feedback to the Spoofer Information Mailing List and invite users to join the Spoofer Users Mailing List for discussion and announcements.
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