- Written by Sulyab Thottungal Valapu
- Posted on December 7, 2020
- Updated on September 4, 2023
- 8625 Views
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.