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 (131.108.131.x/24) can spoof 0 neighboring addresses
Spoofed source address (anon)
Prefix Length
ASN of spoofed source address
Received
131.108.131.x/24
/31
264354
natblock
131.108.131.x/24
/30
264354
natblock
131.108.131.x/24
/29
264354
natblock
131.108.131.x/24
/28
264354
natblock
131.108.131.x/24
/27
264354
natblock
131.108.131.x/24
/26
264354
natblock
131.108.131.x/24
/25
264354
natblock
131.108.131.x/24
/24
264354
natblock
131.108.130.x/24
/23
264354
natblock
131.108.129.x/24
/22
264354
natblock
131.108.135.x/24
/21
263010
rewritten
131.108.139.x/24
/20
61674
rewritten
131.108.147.x/24
/19
61690
rewritten
131.108.163.x/24
/18
61675
rewritten
131.108.195.x/24
/17
263192
rewritten
131.108.3.x/24
/16
61487
rewritten
131.109.131.x/24
/15
14464
rewritten
131.110.131.x/24
/14
UNROUTED
rewritten
131.104.131.x/24
/13
31886
rewritten
131.100.131.x/24
/12
52866
rewritten
131.124.131.x/24
/11
UNROUTED
rewritten
131.76.131.x/24
/10
721
rewritten
131.44.131.x/24
/9
385
rewritten
131.236.131.x/24
/8
23859
rewritten
Meaning of status in Received column:
natblock
Spoofed probe packets appear to be blocked by your local NAT or firewall rather than being rewritten with a public source address.
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.