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 (121.200.4.x/24) can spoof 0 neighboring addresses
Spoofed source address (anon)
Prefix Length
ASN of spoofed source address
Received
121.200.4.x/24
/31
4764
natblock
121.200.4.x/24
/30
4764
natblock
121.200.4.x/24
/29
4764
natblock
121.200.4.x/24
/28
4764
natblock
121.200.4.x/24
/27
4764
natblock
121.200.4.x/24
/26
4764
natblock
121.200.4.x/24
/25
4764
natblock
121.200.4.x/24
/24
4764
natblock
121.200.5.x/24
/23
4764
natblock
121.200.6.x/24
/22
4764
natblock
121.200.0.x/24
/21
136943
natblock
121.200.12.x/24
/20
4764
natblock
121.200.20.x/24
/19
4764
natblock
121.200.36.x/24
/18
10214
natblock
121.200.68.x/24
/17
17849
natblock
121.200.132.x/24
/16
18144
natblock
121.201.4.x/24
/15
58543
natblock
121.202.4.x/24
/14
17924
natblock
121.204.4.x/24
/13
4134
natblock
121.192.4.x/24
/12
4538
natblock
121.216.4.x/24
/11
1221
natblock
121.232.4.x/24
/10
4134
natblock
121.136.4.x/24
/9
4766
natblock
121.72.4.x/24
/8
4768
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.
