Webtagr - Technology News Summarizer

Strange Traffic on IXPs: An Admin's Observations

2025-09-25

The author, operating one of the largest IXP networks on the internet, uses bgp.tools to monitor and reveal a surprising amount of unexpected traffic on IXPs. This includes various routing protocols (OSPF, IS-IS, RIP), auto-addressing protocols (DHCP, IPv6 RA), and vendor-specific protocols (LLDP, CDP, MNDP), all posing security risks like information disclosure and traffic hijacking, even causing outages. The author also highlights bizarre traffic like home networking protocols (UPnP), printer discovery protocols (MDNS), and erroneous broadcast DNS queries stemming from misconfigurations. The author calls for increased traffic monitoring and access controls on IXPs to enhance network security.

(blog.benjojo.co.uk)

Tech traffic monitoring

Widespread Internet Instability Caused by BGP Bug

2025-05-27

On May 20th, 2025, a malformed BGP message containing a corrupt BGP Prefix-SID attribute triggered routing instability and brief outages across the internet. Juniper's JunOS, failing to filter the erroneous message, propagated it to peers, while Arista's EOS reset sessions upon receiving it. The incident impacted numerous networks, including major internet exchanges, as the Bird routing software lacks BGP SID support, resulting in widespread dissemination of the faulty message. Investigation points to AS9304, AS135338, AS151326, and AS138077 as potential sources, with Starcloud (AS135338) or Hutchison (AS9304) considered more likely culprits. This highlights severe flaws in BGP error handling and the need for improved error tolerance in network devices.

(blog.benjojo.co.uk)

Tech Internet Routing

Imaging Mounted Disks Under Duress: A blktrace-Based Solution

2025-01-15

This post details a clever method for backing up system disks when point-in-time snapshots aren't available. The author faced the challenge of needing to back up a system nearing failure that lacked snapshot capabilities, while rebooting or reconfiguring storage was undesirable. The solution leverages Linux's blktrace API to track block device activity in real-time, allowing for complete disk imaging even while data is being written. The author shares their Go-based tool, hot-clone, which tracks modified blocks, ensuring no data loss during imaging. This provides a reliable solution for backing up critical systems in emergency situations.

(blog.benjojo.co.uk)

Development system backup disk imaging

140km TOSLINK: Extending Audio Over Insane Distances

2025-01-07

A hacker successfully transmitted a TOSLINK audio signal over 140km using SFP optical modules, far exceeding its 10-meter design limit. By creatively employing inexpensive TOSLINK ADCs/DACs, an SFP experimenter board, and DWDM fiber channels, he overcame signal attenuation and rate mismatch challenges, achieving inter-city audio transmission. While lacking practical applications, this experiment showcases deep understanding and innovative use of optical transmission technology, prompting reflection on the inner workings of optical components.

(blog.benjojo.co.uk)

Tech optical transmission