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.
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 (208.81.1.x/24) can spoof 0 neighboring addresses
Spoofed source address (anon)
Prefix Length
ASN of spoofed source address
Received
208.81.1.x/24
/31
18451
rewritten
208.81.1.x/24
/30
18451
sendto
208.81.1.x/24
/29
18451
natblock
208.81.1.x/24
/28
18451
rewritten
208.81.1.x/24
/27
18451
rewritten
208.81.1.x/24
/26
18451
rewritten
208.81.1.x/24
/25
18451
rewritten
208.81.1.x/24
/24
18451
rewritten
208.81.0.x/24
/23
18451
rewritten
208.81.3.x/24
/22
18451
rewritten
208.81.5.x/24
/21
18451
rewritten
208.81.9.x/24
/20
30400
rewritten
208.81.17.x/24
/19
UNROUTED
rewritten
208.81.33.x/24
/18
19240
rewritten
208.81.65.x/24
/17
14600
rewritten
208.81.129.x/24
/16
23052
rewritten
208.80.1.x/24
/15
33302
rewritten
208.83.1.x/24
/14
18905
rewritten
208.85.1.x/24
/13
40244
rewritten
208.89.1.x/24
/12
16908
rewritten
208.65.1.x/24
/11
36143
rewritten
208.113.1.x/24
/10
21570
rewritten
208.17.1.x/24
/9
1239
rewritten
208.209.1.x/24
/8
701
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.
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
able to spoof routable, non-adjacent source addresses through the
first 1 IP hop(s).
IPv6 probes:
Spoofed source address
Destination
Received
2001:4978:1fb:6400::d2
2001:48d0:101:501::242
no
2001:49aa:111:aa00::11
2001:48d0:101:501::242
no
fd11:1111:1111::1111
2001:48d0:101:501::242
no
IPv6 Adjacent Netblock Testing:
Spoofed source address (anon)
Prefix Length
ASN of spoofed source address
Received
2605:e200:xx::/40
/120
18451
yes
2605:e200:xx::/40
/112
18451
yes
2605:e200:xx::/40
/104
18451
yes
2605:e200:xx::/40
/96
18451
yes
2605:e200:xx::/40
/88
18451
yes
2605:e200:xx::/40
/80
18451
yes
2605:e200:xx::/40
/72
18451
yes
2605:e200:xx::/40
/64
18451
yes
2605:e200:xx::/40
/56
18451
no
2605:e200:xx::/40
/48
18451
no
2605:e200:xx::/40
/40
18451
no
2605:e200:80xx::/40
/32
18451
no
2605:e280:xx::/40
/24
UNROUTED
no
2605:6200:xx::/40
/16
UNROUTED
no
Meaning of status in Received column:
no
Packets spoofed from adjacent netblock were not received, probably due to blocking
yes
Packets spoofed from adjacent netblock were received (but that netblock is within the source AS)
Summary:
The results from all tests are aggregated to produce a summary
"State of IP Spoofing" report.