Session Report
Test run at: 2026-01-28 08:53:10 GMT
Client Prefix (v4): 51.191.138.x/24
Client AS (v4): 5607 (BSKYB-BROADBAND-AS)
IPv4 Probes: 162
Outbound spoofing summary (from the client to our server) Source address type IPv4 Private - RFC1918 rewritten Routable rewritten Largest spoofable neighbor prefix length none
Spoof status key received Spoofed packet was received. ✔ Pattern of tests from this IP block indicates a switch from allowing spoofing to blocking it. rewritten Spoofed packet was received, but the source address was changed en route. blocked Spoofed packet was not received, but unspoofed packet was. unknown Neither spoofed nor unspoofed packet was received.
Warnings:
- ⚠️ Your host is behind a Network Address Translation (NAT) router or firewall which rewrites the source addresses of the test traffic. To test your provider's network further, you must remove the NAT/firewall/router and connect directly.
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 (51.191.138.x/24) can spoof 0 neighboring addresses
Spoofed source address (anon) Prefix
LengthASN of spoofed
source addressReceived 51.191.138.x/24 /31 5607 rewritten 51.191.138.x/24 /30 5607 rewritten 51.191.138.x/24 /29 5607 rewritten 51.191.138.x/24 /28 5607 rewritten 51.191.138.x/24 /27 5607 rewritten 51.191.138.x/24 /26 5607 rewritten 51.191.138.x/24 /25 5607 rewritten 51.191.138.x/24 /24 5607 rewritten 51.191.139.x/24 /23 5607 rewritten 51.191.136.x/24 /22 5607 rewritten 51.191.142.x/24 /21 5607 rewritten 51.191.130.x/24 /20 5607 rewritten 51.191.154.x/24 /19 5607 rewritten 51.191.170.x/24 /18 5607 rewritten 51.191.202.x/24 /17 5607 rewritten 51.191.10.x/24 /16 5607 rewritten 51.190.138.x/24 /15 5607 rewritten 51.189.138.x/24 /14 16509 rewritten 51.187.138.x/24 /13 5607 rewritten 51.183.138.x/24 /12 5607 rewritten 51.175.138.x/24 /11 29695 rewritten 51.159.138.x/24 /10 12876 rewritten 51.255.138.x/24 /9 16276 rewritten 51.63.138.x/24 /8 UNROUTED rewritten Meaning of status in Received column:
rewritten The source address of the probe packets we received differs from the spoofed address. It appears that an intermediate device is rewriting your packet headers.
IPv4 Outbound Filtering Depth:
The tracefilter test found your host able to spoof routable, non-adjacent source addresses through the first 1 IP hop(s).Summary:
The results from all tests are aggregated to produce a summary "State of IP Spoofing" report.Feedback:
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