In response to feedback from operational security communities, CAIDA's source address validation measurement project (https://spoofer.caida.org) is automatically generating monthly reports of ASes originating prefixes in BGP for systems from which we received packets with a spoofed source address. We are publishing these reports to network and security operations lists in order to ensure this information reaches operational contacts in these ASes. This report summarises tests conducted within nld. Inferred improvements during Dec 2020: ASN Name Fixed-By 34373 XXLnet 2020-12-15 Further information for the inferred remediation is available at: https://spoofer.caida.org/remedy.php Source Address Validation issues inferred during Dec 2020: ASN Name First-Spoofed Last-Spoofed 33915 TNF 2019-01-28 2020-12-04 8587 Infracom 2019-10-28 2020-12-18 213268 2020-12-07 2020-12-28 Further information for these tests where we received spoofed packets is available at: https://spoofer.caida.org/recent_tests.php?country_include=nld&no_block=1 Source Address Validation issues inferred during Dec 2020 using open resolver tests: ASN Name Last-Detected 45040 EXTRAIP 2020-12-04 1136 KPN 2020-12-04 14061 DIGITALOCEAN-ASN 2020-12-03 9009 M247 2020-12-03 61044 SIT 2020-12-03 Further information for these tests is available at: https://spoofer.caida.org/ornog.php?country_include=nld Please send any feedback or suggestions to spoofer-info@caida.org