Session Report

Summary:

Test run at: 2026-04-30 08:53:33 GMT
Client Prefix (v4): 88.102.242.x/24
Client AS (v4): 5610 (O2-CZECH-REPUBLIC)
IPv4 Probes: 162
Client Prefix (v6): 2a00:1028:91xx::/40
Client AS (v6): 5610 (O2-CZECH-REPUBLIC)
IPv6 Probes: 180

Outbound spoofing summary (from the client to our server)
Source address type	IPv4		IPv6
Private - RFC1918 or ULA	blocked		blocked
Routable	blocked		blocked
Largest spoofable neighbor prefix length	none		/64

Spoof status key
received		Spoofed packet was received.	✔	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 (88.102.242.x/24) can spoof 0 neighboring addresses

Spoofed source address (anon)	Prefix Length	ASN of spoofed source address	Received
88.102.242.x/24	/31	5610	natblock
88.102.242.x/24	/30	5610	natblock
88.102.242.x/24	/29	5610	natblock
88.102.242.x/24	/28	5610	natblock
88.102.242.x/24	/27	5610	natblock
88.102.242.x/24	/26	5610	natblock
88.102.242.x/24	/25	5610	natblock
88.102.242.x/24	/24	5610	natblock
88.102.243.x/24	/23	5610	natblock
88.102.240.x/24	/22	5610	natblock
88.102.246.x/24	/21	5610	natblock
88.102.250.x/24	/20	5610	natblock
88.102.226.x/24	/19	5610	natblock
88.102.210.x/24	/18	5610	natblock
88.102.178.x/24	/17	5610	natblock
88.102.114.x/24	/16	5610	natblock
88.103.242.x/24	/15	5610	natblock
88.100.242.x/24	/14	5610	natblock
88.98.242.x/24	/13	56478	natblock
88.110.242.x/24	/12	UNROUTED	natblock
88.118.242.x/24	/11	8764	natblock
88.70.242.x/24	/10	3209	natblock
88.38.242.x/24	/9	3269	natblock
88.230.242.x/24	/8	9121	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.

IPv6 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.

IPv6 probes:

Spoofed source address	Destination	Received
2001:48d0:101:501::159	2001:19f0:1000:363e:5400:4ff:fea6:6a66	no
2001:4978:1fb:6400::d2	2001:19f0:1000:363e:5400:4ff:fea6:6a66	no
2001:49aa:111:aa00::11	2001:19f0:1000:363e:5400:4ff:fea6:6a66	no
fd11:1111:1111::1111	2001:19f0:1000:363e:5400:4ff:fea6:6a66	no
2001:48d0:101:501::159	2001:19f0:5401:182d:5400:4ff:fea6:69f9	no
2001:4978:1fb:6400::d2	2001:19f0:5401:182d:5400:4ff:fea6:69f9	no
2001:49aa:111:aa00::11	2001:19f0:5401:182d:5400:4ff:fea6:69f9	no
fd11:1111:1111::1111	2001:19f0:5401:182d:5400:4ff:fea6:69f9	no
2001:48d0:101:501::159	2001:19f0:5c00:1e23:5400:4ff:fea6:6b47	no
2001:4978:1fb:6400::d2	2001:19f0:5c00:1e23:5400:4ff:fea6:6b47	no
2001:49aa:111:aa00::11	2001:19f0:5c00:1e23:5400:4ff:fea6:6b47	no
fd11:1111:1111::1111	2001:19f0:5c00:1e23:5400:4ff:fea6:6b47	no
2001:48d0:101:501::159	2001:19f0:6001:5827:5400:4ff:fea6:6ab2	no
2001:4978:1fb:6400::d2	2001:19f0:6001:5827:5400:4ff:fea6:6ab2	no
2001:49aa:111:aa00::11	2001:19f0:6001:5827:5400:4ff:fea6:6ab2	no
fd11:1111:1111::1111	2001:19f0:6001:5827:5400:4ff:fea6:6ab2	no
2001:48d0:101:501::159	2001:19f0:6402:893:5400:4ff:fea6:6a5c	no
2001:4978:1fb:6400::d2	2001:19f0:6402:893:5400:4ff:fea6:6a5c	no
2001:49aa:111:aa00::11	2001:19f0:6402:893:5400:4ff:fea6:6a5c	no
fd11:1111:1111::1111	2001:19f0:6402:893:5400:4ff:fea6:6a5c	no
2001:48d0:101:501::159	2001:19f0:6801:6b9:5400:4ff:fea6:6a34	no
2001:4978:1fb:6400::d2	2001:19f0:6801:6b9:5400:4ff:fea6:6a34	no
2001:49aa:111:aa00::11	2001:19f0:6801:6b9:5400:4ff:fea6:6a34	no
fd11:1111:1111::1111	2001:19f0:6801:6b9:5400:4ff:fea6:6a34	no
2001:48d0:101:501::159	2001:19f0:6c00:1da9:5400:4ff:fea6:6a74	no
2001:4978:1fb:6400::d2	2001:19f0:6c00:1da9:5400:4ff:fea6:6a74	no
2001:49aa:111:aa00::11	2001:19f0:6c00:1da9:5400:4ff:fea6:6a74	no
fd11:1111:1111::1111	2001:19f0:6c00:1da9:5400:4ff:fea6:6a74	no
2001:48d0:101:501::159	2001:19f0:7402:9aa:5400:4ff:fea6:6ac6	no
2001:4978:1fb:6400::d2	2001:19f0:7402:9aa:5400:4ff:fea6:6ac6	no
2001:49aa:111:aa00::11	2001:19f0:7402:9aa:5400:4ff:fea6:6ac6	no
fd11:1111:1111::1111	2001:19f0:7402:9aa:5400:4ff:fea6:6ac6	no
2001:48d0:101:501::159	2001:19f0:9003:8b9:5400:4ff:fea6:6b22	no
2001:4978:1fb:6400::d2	2001:19f0:9003:8b9:5400:4ff:fea6:6b22	no
2001:49aa:111:aa00::11	2001:19f0:9003:8b9:5400:4ff:fea6:6b22	no
fd11:1111:1111::1111	2001:19f0:9003:8b9:5400:4ff:fea6:6b22	no
2001:48d0:101:501::159	2001:19f0:ac00:3671:5400:4ff:fea6:6b71	no
2001:4978:1fb:6400::d2	2001:19f0:ac00:3671:5400:4ff:fea6:6b71	no
2001:49aa:111:aa00::11	2001:19f0:ac00:3671:5400:4ff:fea6:6b71	no
fd11:1111:1111::1111	2001:19f0:ac00:3671:5400:4ff:fea6:6b71	no
2001:48d0:101:501::159	2001:19f0:b002:1ef:5400:4ff:fea6:6be9	no
2001:4978:1fb:6400::d2	2001:19f0:b002:1ef:5400:4ff:fea6:6be9	no
2001:49aa:111:aa00::11	2001:19f0:b002:1ef:5400:4ff:fea6:6be9	no
fd11:1111:1111::1111	2001:19f0:b002:1ef:5400:4ff:fea6:6be9	no
2001:48d0:101:501::159	2001:19f0:b400:16a4:5400:4ff:fea6:6b0d	no
2001:4978:1fb:6400::d2	2001:19f0:b400:16a4:5400:4ff:fea6:6b0d	no
2001:49aa:111:aa00::11	2001:19f0:b400:16a4:5400:4ff:fea6:6b0d	no
fd11:1111:1111::1111	2001:19f0:b400:16a4:5400:4ff:fea6:6b0d	no
2001:48d0:101:501::159	2001:19f0:b800:1b21:5400:4ff:fea5:cd5a	no
2001:4978:1fb:6400::d2	2001:19f0:b800:1b21:5400:4ff:fea5:cd5a	no
2001:49aa:111:aa00::11	2001:19f0:b800:1b21:5400:4ff:fea5:cd5a	no
fd11:1111:1111::1111	2001:19f0:b800:1b21:5400:4ff:fea5:cd5a	no
2001:48d0:101:501::159	2001:19f0:c000:d254:5400:4ff:fea5:cd47	no
2001:4978:1fb:6400::d2	2001:19f0:c000:d254:5400:4ff:fea5:cd47	no
2001:49aa:111:aa00::11	2001:19f0:c000:d254:5400:4ff:fea5:cd47	no
fd11:1111:1111::1111	2001:19f0:c000:d254:5400:4ff:fea5:cd47	no
2001:48d0:101:501::159	2001:19f0:c800:2f95:5400:4ff:fea6:6b55	no
2001:4978:1fb:6400::d2	2001:19f0:c800:2f95:5400:4ff:fea6:6b55	no
2001:49aa:111:aa00::11	2001:19f0:c800:2f95:5400:4ff:fea6:6b55	no
fd11:1111:1111::1111	2001:19f0:c800:2f95:5400:4ff:fea6:6b55	no
2001:48d0:101:501::159	2001:48d0:101:501::242	no
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
2001:48d0:101:501::159	2401:c080:1000:4fdc:5400:4ff:fea6:6b3a	no
2001:4978:1fb:6400::d2	2401:c080:1000:4fdc:5400:4ff:fea6:6b3a	no
2001:49aa:111:aa00::11	2401:c080:1000:4fdc:5400:4ff:fea6:6b3a	no
fd11:1111:1111::1111	2401:c080:1000:4fdc:5400:4ff:fea6:6b3a	no
2001:48d0:101:501::159	2401:c080:1400:763f:5400:4ff:fea6:6b65	no
2001:4978:1fb:6400::d2	2401:c080:1400:763f:5400:4ff:fea6:6b65	no
2001:49aa:111:aa00::11	2401:c080:1400:763f:5400:4ff:fea6:6b65	no
fd11:1111:1111::1111	2401:c080:1400:763f:5400:4ff:fea6:6b65	no
2001:48d0:101:501::159	2401:c080:1800:4f38:5400:4ff:fea6:6ba4	no
2001:4978:1fb:6400::d2	2401:c080:1800:4f38:5400:4ff:fea6:6ba4	no
2001:49aa:111:aa00::11	2401:c080:1800:4f38:5400:4ff:fea6:6ba4	no
fd11:1111:1111::1111	2401:c080:1800:4f38:5400:4ff:fea6:6ba4	no
2001:48d0:101:501::159	2401:c080:1c00:2303:5400:4ff:fea6:6a7e	no
2001:4978:1fb:6400::d2	2401:c080:1c00:2303:5400:4ff:fea6:6a7e	no
2001:49aa:111:aa00::11	2401:c080:1c00:2303:5400:4ff:fea6:6a7e	no
fd11:1111:1111::1111	2401:c080:1c00:2303:5400:4ff:fea6:6a7e	no
2001:48d0:101:501::159	2401:c080:2000:1929:5400:4ff:fea6:6b07	no
2001:4978:1fb:6400::d2	2401:c080:2000:1929:5400:4ff:fea6:6b07	no
2001:49aa:111:aa00::11	2401:c080:2000:1929:5400:4ff:fea6:6b07	no
fd11:1111:1111::1111	2401:c080:2000:1929:5400:4ff:fea6:6b07	no
2001:48d0:101:501::159	2401:c080:2400:167d:5400:4ff:fea6:6a20	no
2001:4978:1fb:6400::d2	2401:c080:2400:167d:5400:4ff:fea6:6a20	no
2001:49aa:111:aa00::11	2401:c080:2400:167d:5400:4ff:fea6:6a20	no
fd11:1111:1111::1111	2401:c080:2400:167d:5400:4ff:fea6:6a20	no
2001:48d0:101:501::159	2401:c080:3000:27ce:5400:4ff:fea6:6a0b	no
2001:4978:1fb:6400::d2	2401:c080:3000:27ce:5400:4ff:fea6:6a0b	no
2001:49aa:111:aa00::11	2401:c080:3000:27ce:5400:4ff:fea6:6a0b	no
fd11:1111:1111::1111	2401:c080:3000:27ce:5400:4ff:fea6:6a0b	no
2001:48d0:101:501::159	2401:c080:3400:2851:5400:4ff:fea6:6a4d	no
2001:4978:1fb:6400::d2	2401:c080:3400:2851:5400:4ff:fea6:6a4d	no
2001:49aa:111:aa00::11	2401:c080:3400:2851:5400:4ff:fea6:6a4d	no
fd11:1111:1111::1111	2401:c080:3400:2851:5400:4ff:fea6:6a4d	no
2001:48d0:101:501::159	2401:c080:3800:3731:5400:4ff:fea6:6a90	no
2001:4978:1fb:6400::d2	2401:c080:3800:3731:5400:4ff:fea6:6a90	no
2001:49aa:111:aa00::11	2401:c080:3800:3731:5400:4ff:fea6:6a90	no
fd11:1111:1111::1111	2401:c080:3800:3731:5400:4ff:fea6:6a90	no
2001:48d0:101:501::159	2a05:f480:1400:28fc:5400:4ff:fea6:69e9	no
2001:4978:1fb:6400::d2	2a05:f480:1400:28fc:5400:4ff:fea6:69e9	no
2001:49aa:111:aa00::11	2a05:f480:1400:28fc:5400:4ff:fea6:69e9	no
fd11:1111:1111::1111	2a05:f480:1400:28fc:5400:4ff:fea6:69e9	no
2001:48d0:101:501::159	2a05:f480:2000:1f7b:5400:4ff:fea6:6b85	no
2001:4978:1fb:6400::d2	2a05:f480:2000:1f7b:5400:4ff:fea6:6b85	no
2001:49aa:111:aa00::11	2a05:f480:2000:1f7b:5400:4ff:fea6:6b85	no
fd11:1111:1111::1111	2a05:f480:2000:1f7b:5400:4ff:fea6:6b85	no
2001:48d0:101:501::159	2a05:f480:2400:1f3f:5400:4ff:fea6:6bdb	no
2001:4978:1fb:6400::d2	2a05:f480:2400:1f3f:5400:4ff:fea6:6bdb	no
2001:49aa:111:aa00::11	2a05:f480:2400:1f3f:5400:4ff:fea6:6bdb	no
fd11:1111:1111::1111	2a05:f480:2400:1f3f:5400:4ff:fea6:6bdb	no
2001:48d0:101:501::159	2a05:f480:2800:16b7:5400:4ff:fea6:6adf	no
2001:4978:1fb:6400::d2	2a05:f480:2800:16b7:5400:4ff:fea6:6adf	no
2001:49aa:111:aa00::11	2a05:f480:2800:16b7:5400:4ff:fea6:6adf	no
fd11:1111:1111::1111	2a05:f480:2800:16b7:5400:4ff:fea6:6adf	no
2001:48d0:101:501::159	2a05:f480:2c00:15ba:5400:4ff:fea6:6bcc	no
2001:4978:1fb:6400::d2	2a05:f480:2c00:15ba:5400:4ff:fea6:6bcc	no
2001:49aa:111:aa00::11	2a05:f480:2c00:15ba:5400:4ff:fea6:6bcc	no
fd11:1111:1111::1111	2a05:f480:2c00:15ba:5400:4ff:fea6:6bcc	no
2001:48d0:101:501::159	2a05:f480:3000:22ab:5400:4ff:fea6:6aa6	no
2001:4978:1fb:6400::d2	2a05:f480:3000:22ab:5400:4ff:fea6:6aa6	no
2001:49aa:111:aa00::11	2a05:f480:3000:22ab:5400:4ff:fea6:6aa6	no
fd11:1111:1111::1111	2a05:f480:3000:22ab:5400:4ff:fea6:6aa6	no
2001:48d0:101:501::159	2a05:f480:3400:294b:5400:4ff:fea6:6af1	no
2001:4978:1fb:6400::d2	2a05:f480:3400:294b:5400:4ff:fea6:6af1	no
2001:49aa:111:aa00::11	2a05:f480:3400:294b:5400:4ff:fea6:6af1	no
fd11:1111:1111::1111	2a05:f480:3400:294b:5400:4ff:fea6:6af1	no

IPv6 Adjacent Netblock Testing:

Spoofed source address (anon)	Prefix Length	ASN of spoofed source address	Received
2a00:1028:91xx::/40	/120	5610	yes
2a00:1028:91xx::/40	/112	5610	yes
2a00:1028:91xx::/40	/104	5610	yes
2a00:1028:91xx::/40	/96	5610	yes
2a00:1028:91xx::/40	/88	5610	yes
2a00:1028:91xx::/40	/80	5610	yes
2a00:1028:91xx::/40	/72	5610	yes
2a00:1028:91xx::/40	/64	5610	yes
2a00:1028:91xx::/40	/56	5610	no
2a00:1028:91xx::/40	/48	5610	no
2a00:1028:91xx::/40	/40	5610	no
2a00:1028:11xx::/40	/32	5610	no
2a00:10a8:91xx::/40	/24	UNROUTED	no
2a00:9028:91xx::/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.

Feedback:

We welcome questions and feedback to the Spoofer Information Mailing List and invite users to join the Spoofer Users Mailing List for discussion and announcements.