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 (72.20.140.x/24) can spoof 0 neighboring addresses
Spoofed source address (anon)
Prefix Length
ASN of spoofed source address
Received
72.20.140.x/24
/31
394437
natblock
72.20.140.x/24
/30
394437
natblock
72.20.140.x/24
/29
394437
natblock
72.20.140.x/24
/28
394437
natblock
72.20.140.x/24
/27
394437
natblock
72.20.140.x/24
/26
394437
natblock
72.20.140.x/24
/25
394437
natblock
72.20.140.x/24
/24
394437
natblock
72.20.141.x/24
/23
22442
natblock
72.20.142.x/24
/22
22442
natblock
72.20.136.x/24
/21
22442
natblock
72.20.132.x/24
/20
394437
natblock
72.20.156.x/24
/19
394437
natblock
72.20.172.x/24
/18
25606
natblock
72.20.204.x/24
/17
6461
natblock
72.20.12.x/24
/16
46562
natblock
72.21.140.x/24
/15
7029
natblock
72.22.140.x/24
/14
14813
natblock
72.16.140.x/24
/13
17184
natblock
72.28.140.x/24
/12
UNROUTED
natblock
72.4.140.x/24
/11
3064
natblock
72.52.140.x/24
/10
32244
natblock
72.84.140.x/24
/9
701
natblock
72.148.140.x/24
/8
7018
natblock
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.
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.
