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 (192.40.240.x/24) can spoof 4194303 neighboring addresses (within your /10 prefix)
Spoofed source address (anon)
Prefix Length
ASN of spoofed source address
Received
192.40.240.x/24
/31
33044
natblock
192.40.240.x/24
/30
33044
natblock
192.40.240.x/24
/29
33044
yes
192.40.240.x/24
/28
33044
yes
192.40.240.x/24
/27
33044
yes
192.40.240.x/24
/26
33044
yes
192.40.240.x/24
/25
33044
yes
192.40.240.x/24
/24
33044
yes
192.40.241.x/24
/23
33044
yes
192.40.242.x/24
/22
33044
yes
192.40.244.x/24
/21
395317
yes
192.40.248.x/24
/20
UNROUTED
natblock
192.40.224.x/24
/19
25222
yes
192.40.208.x/24
/18
UNROUTED
natblock
192.40.176.x/24
/17
36351
yes
192.40.112.x/24
/16
33494
yes
192.41.240.x/24
/15
UNROUTED
natblock
192.42.240.x/24
/14
3549
yes
192.44.240.x/24
/13
19399
yes
192.32.240.x/24
/12
UNROUTED
natblock
192.56.240.x/24
/11
UNROUTED
natblock
192.8.240.x/24
/10
24084
yes
192.104.240.x/24
/9
UNROUTED
natblock
192.168.240.x/24
/8
UNROUTED
rewritten
Meaning of status in Received column:
yes
Packets spoofed from adjacent netblock were received
yes
Packets spoofed from adjacent netblock were received (but that netblock is within the source AS)
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 5 IP hop(s).
Summary:
The results from all tests are aggregated to produce a summary
"State of IP Spoofing" report.
