BGP
Day 65 — Route-Leak and Prefix-Hijack Incident Containment
1. Opening A sudden path change can look like a hijack even when the real problem is a customer's accidental transit leak, a stale ROA,...
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Practical network engineering
Learn Cisco, BGP and network security the way it works in production.
Step-by-step guides, labs and troubleshooting notes for CCNA, CCNP, routing, firewalls and automation. Written for engineers who want to understand the why, not just paste commands.
Latest guides
BGP
Day 64 — BGP BLACKHOLE Community and Remote Triggered Black Holing
1. Opening During a volumetric attack, preserving the rest of the network can require intentionally discarding traffic to the attacked dest...
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Bogon
Day 63 — Bogon, Special-Purpose and Source-Address Filtering at the Internet Edge
1. Opening 'Bogon filtering' is often taught as a static list of prefixes that should never appear. That model ages badly. IPv4 all...
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Prefix Ownership Reconciliation: IRR
Day 62 — Prefix Ownership Reconciliation: IRR, RPKI and Customer Authorization
1. Opening Customer onboarding often produces three different prefix lists: what the customer says it owns, what an IRR says it will announ...
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IRR
Day 61 — IRR, RPSL, Route Objects and AS-SET Based Filtering
1. Opening Internet Routing Registries exist so operators can publish routing-policy information in a structured form. That information can...
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