BGP.guru

BGP.guru

A Nerd blog.

25 Nov 2014

Phased Service Moves

Multi-phase migration to BGP-announced IP space: AS62758 turnup, moving LMS and external services from provider IPs, pre-change testing with reduced DNS TTLs, 1:1 NAT configs, and phased rollout strategy.
21 Nov 2014

Service Status via SaltStack 2014.7 with Nagios

Exploring SaltStack 2014.7's nagios module: remote execution of nagios-plugins on minions, pillar-defined check lists with Jinja templating, distributed monitoring ideas, and contributing documentation fixes to SaltStack.
08 Nov 2014

New and Removed ASNs

Automating Canadian ASN discovery using Blockfinder: daily diff emails tracking ARIN assignments, patching TTY progress bar issues for cron jobs, and proposing ARIN's arin-issued list for AS numbers (later implemented).
23 Oct 2014

Troubleshooting ICMPv6 with tcpdump

Fixing OpenBSD PF firewall ICMPv6 rules by using tcpdump to identify required neighbor discovery types (133-137): isolating NDP traffic with packet filters and properly allowing router/neighbor solicitation/advertisement messages.
16 Oct 2014

Internet Connection Sharing

Tracking down rogue DHCP server on corporate network: using arpwatch to identify Mac sharing causing 192.168.137.x leases, correlating MAC to CDP/switch port, and why DHCP snooping prevents these issues.