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.
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 (121.73.13.x/24) can spoof 0 neighboring addresses
Spoofed source address (anon)
Prefix Length
ASN of spoofed source address
Received
121.73.13.x/24
/31
4768
sendto
121.73.13.x/24
/30
4768
sendto
121.73.13.x/24
/29
4768
sendto
121.73.13.x/24
/28
4768
sendto
121.73.13.x/24
/27
4768
sendto
121.73.13.x/24
/26
4768
sendto
121.73.13.x/24
/25
4768
sendto
121.73.13.x/24
/24
4768
sendto
121.73.12.x/24
/23
4768
sendto
121.73.15.x/24
/22
4768
sendto
121.73.9.x/24
/21
4768
sendto
121.73.5.x/24
/20
4768
sendto
121.73.29.x/24
/19
4768
sendto
121.73.45.x/24
/18
4768
sendto
121.73.77.x/24
/17
4768
sendto
121.73.141.x/24
/16
4768
sendto
121.72.13.x/24
/15
4768
sendto
121.75.13.x/24
/14
9500
sendto
121.77.13.x/24
/13
9812
sendto
121.65.13.x/24
/12
3786
sendto
121.89.13.x/24
/11
UNROUTED
sendto
121.105.13.x/24
/10
2516
sendto
121.9.13.x/24
/9
134764
sendto
121.201.13.x/24
/8
58543
sendto
Meaning of status in Received column:
sendto
The spoofer client was unable to send spoofed headers due to an operating system restriction.
IPv4 Outbound Filtering Depth:
The tracefilter test found your host
unable to spoof routable, non-adjacent source addresses through
even the first IP hop.
Summary:
The results from all tests are aggregated to produce a summary
"State of IP Spoofing" report.