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 32767 neighboring addresses (within your /17 prefix)
Spoofed source address (anon)
Prefix Length
ASN of spoofed source address
Received
121.73.13.x/24
/31
4768
yes
121.73.13.x/24
/30
4768
natblock
121.73.13.x/24
/29
4768
natblock
121.73.13.x/24
/28
4768
natblock
121.73.13.x/24
/27
4768
yes
121.73.13.x/24
/26
4768
yes
121.73.13.x/24
/25
4768
yes
121.73.13.x/24
/24
4768
yes
121.73.12.x/24
/23
4768
yes
121.73.15.x/24
/22
4768
yes
121.73.9.x/24
/21
4768
natblock
121.73.5.x/24
/20
4768
natblock
121.73.29.x/24
/19
4768
yes
121.73.45.x/24
/18
4768
natblock
121.73.77.x/24
/17
4768
yes
121.73.141.x/24
/16
4768
natblock
121.72.13.x/24
/15
4768
natblock
121.75.13.x/24
/14
9500
natblock
121.77.13.x/24
/13
9812
natblock
121.65.13.x/24
/12
3786
natblock
121.89.13.x/24
/11
UNROUTED
natblock
121.105.13.x/24
/10
2516
natblock
121.9.13.x/24
/9
134764
natblock
121.201.13.x/24
/8
38372
natblock
Meaning of status in Received column:
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.
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.
