https://www.pistack.xyz/tags/bier/ Recent content in Bier on Pi Stack Hugo en-us Thu, 21 May 2026 00:00:00 +0000 https://www.pistack.xyz/posts/2026-05-21-self-hosted-bier-forwarding-frr-vpp-linux-kernel-guide/ Thu, 21 May 2026 00:00:00 +0000 https://www.pistack.xyz/posts/2026-05-21-self-hosted-bier-forwarding-frr-vpp-linux-kernel-guide/ <p>Bit Indexed Explicit Replication (BIER) is an IETF-standard multicast forwarding architecture that eliminates the need for explicit tree-building protocols like PIM. Instead of maintaining per-flow state in every router along a distribution tree, BIER encodes the set of destinations directly in the packet header using a compact bitstring. Each bit represents a specific egress router (BFER), and intermediate routers (BFRs) forward packets based solely on the bitstring — dramatically reducing state overhead and improving scalability.</p>