Spoofing Information for AS 8220 (COLT)

Spoofing status per IP block for last year of data

(Results for all dates also available.)
Spoof status key
receivedSpoofed packet was received.Pattern of tests from this IP block indicates a switch from allowing spoofing to blocking it.
rewrittenSpoofed packet was received, but the source address was changed en route.
blockedSpoofed packet was not received, but unspoofed packet was.
unknownNeither spoofed nor unspoofed packet was received.
IP blockLatest testSpoof
57.133.7.x/242023-11-28 14:16:21 GMTblockedblocked
157.120.255.x/242023-04-10 02:01:57 GMTblockedblocked

Customers of AS 8220 we have spoofer tests from

This is the list of directly connected customers of AS 8220 from which we have received a spoofer test, ordered by the customer's ability to send spoofed packets and the number of prefixes of an inferred ingress ACL derived from prefix announcements for the customer recorded in the latest month of public BGP data. BCP-84 describes ingress ACLs as "the most bulletproof solution when done properly" and the "best fit ... when the configuration is not too dynamic, ... if the number of used prefixes is low." Further detail about the size and dynamism of an inferred ACL is available by following the History link for each AS.

ASNCountryNumber of Prefixes
in Customer Cone
Number of ASes
in Customer Cone
22883 (CONDENAST)usa (United States)60AS 22883 testsreceived
2121 (RIPE-MEETING-AS)nld (Netherlands)20AS 2121 testsblocked
202032 (GOLINE)che (Switzerland)20AS 202032 testsblocked
20694 (NMMN-AS)deu (Germany)91AS 20694 testsblocked
15699 (AS_ADAM)esp (Spain)274AS 15699 testsblocked
51167 (CONTABO)deu (Germany)2744AS 51167 testsblocked
15576 (NTS)che (Switzerland)42889AS 15576 testsblocked
13213 (UK2NET-AS)gbr (United Kingdom)4968AS 13213 testsblocked
31898 (ORACLE-BMC-31898)bra (Brazil)86122AS 31898 testsblocked
29802 (HVC-AS)usa (United States)161892AS 29802 testsblocked

Address Space Announcement History

The customer cone for 8220 is too large for a prefix list to be useful.

Last Modified