- Written by Sulyab Thottungal Valapu
- Posted on December 7, 2020
- Updated on September 4, 2023
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This document describes the OSPFv2 feature that allows the setting of “Down” (DN) bit in type-5 and type-7 LSAs. The DN Bit is a loop prevention mechanism implemented when OSPF is used as CE - PE IGP protocol. Its usage in OSPF is explained by RFC4576. By default, OSPF honors the DN-bit in type-3, type-5 or type-7 LSAs in non-default VRFs.