title: Measuring the effectiveness of routing defenses through the lens of DROP

authors: Oliver-Dowling, Leo

subjects: Computer networking

abstract: This work analyzes the properties of 712 prefixes that appeared in Spamhaus’ “Don’t Route Or Peer” (DROP) list over a nearly three-year period from June 2019 to March 2022. The 712 known abused prefixes are used as a lens to assess the current threat landscape and evaluate several of the leading rout- ing defense mechanisms. A thorough characterization of these 712 prefixes is performed and it is found that a larger fraction of the hijacked prefixes were from Regional Internet Registries (RIRs) with restrictive policies regarding Resource Public Key Infrastructure (RPKI) eligibility. It is also found that attackers were predominately targeting address space that was unrouted and not RPKI-signed. The work reveals that attackers were subverting multiple defenses against malicious use of address space, including creating fraudu- lent Internet Routing Registry records for prefixes shortly before using them. Other attackers disguised their activities by announcing routes with origin Autonomous Systems (ASes) consistent with historic route announcements, and in one case, with the Autonomous System Number (ASN) in a RPKI Route Origin Authorization. Finally, the work quantifies the substantial and actively-exploited surface in unrouted space, which warrants reconsideration of RPKI eligibility and policies by both operators and RIRs.

text: Measuring the effectiveness of routing defenses through the lens of DROP This work analyzes the properties of 712 prefixes that appeared in Spamhaus’ “Don’t Route Or Peer” (DROP) list over a nearly three-year period from June 2019 to March 2022. The 712 known abused prefixes are used as a lens to assess the current threat landscape and evaluate several of the leading rout- ing defense mechanisms. A thorough characterization of these 712 prefixes is performed and it is found that a larger fraction of the hijacked prefixes were from Regional Internet Registries (RIRs) with restrictive policies regarding Resource Public Key Infrastructure (RPKI) eligibility. It is also found that attackers were predominately targeting address space that was unrouted and not RPKI-signed. The work reveals that attackers were subverting multiple defenses against malicious use of address space, including creating fraudu- lent Internet Routing Registry records for prefixes shortly before using them. Other attackers disguised their activities by announcing routes with origin Autonomous Systems (ASes) consistent with historic route announcements, and in one case, with the Autonomous System Number (ASN) in a RPKI Route Origin Authorization. Finally, the work quantifies the substantial and actively-exploited surface in unrouted space, which warrants reconsideration of RPKI eligibility and policies by both operators and RIRs.

year: 2022

title: Comparison of injuries to New Zealand rock lobsters (Jasus edwardsii) caused by hand versus snare collection

authors: Powrie, Warrick

subjects: autotomy

abstract: Following the prohibition in New Zealand of lobster snares in late 2005, we undertook research to compare the frequency and extent of injuries to rock lobsters (Jasus edwardsii) (Hutton) caused by recreational SCUBA divers using lobster snares compared with hand collection. Rock lobsters were sampled between January 2006 and October 2006 from multiple dive sites around the North Island of New Zealand. Of the 124 rock lobsters caught, 20.9% were in a soft shell state. Female rock lobsters constituted 43.5% of the catch, but only one was carrying eggs. Female mean tail width was 72.2 mm; male mean tail width was 71.9 mm. We found that hand collection caused significantly more injuries than snare collection, to both soft shell and hard shell animals. Hand collection also resulted in more major injuries, with 18% of hard shell animals and 31% of soft shell animals losing two or more limbs. We recommend that the prohibition on the use of rock lobster snares be lifted, as their use appears to significantly reduce injury and stress to rock lobsters in recreational dive areas, and increase the survival of undersized individuals released after capture.

text: Comparison of injuries to New Zealand rock lobsters (Jasus edwardsii) caused by hand versus snare collection Following the prohibition in New Zealand of lobster snares in late 2005, we undertook research to compare the frequency and extent of injuries to rock lobsters (Jasus edwardsii) (Hutton) caused by recreational SCUBA divers using lobster snares compared with hand collection. Rock lobsters were sampled between January 2006 and October 2006 from multiple dive sites around the North Island of New Zealand. Of the 124 rock lobsters caught, 20.9% were in a soft shell state. Female rock lobsters constituted 43.5% of the catch, but only one was carrying eggs. Female mean tail width was 72.2 mm; male mean tail width was 71.9 mm. We found that hand collection caused significantly more injuries than snare collection, to both soft shell and hard shell animals. Hand collection also resulted in more major injuries, with 18% of hard shell animals and 31% of soft shell animals losing two or more limbs. We recommend that the prohibition on the use of rock lobster snares be lifted, as their use appears to significantly reduce injury and stress to rock lobsters in recreational dive areas, and increase the survival of undersized individuals released after capture.

year: 2009

title: He pao

authors: Roa, Tom

subjects: Pao

abstract: Ko Te Whare Wānanga O Waikato" te ingoa o tētehi pao nāku i tito hei waiata mā Te Whare Wānanga O Waikato, i te tau 2004.

text: He pao Ko Te Whare Wānanga O Waikato" te ingoa o tētehi pao nāku i tito hei waiata mā Te Whare Wānanga O Waikato, i te tau 2004.

year: 2012-05