Draining an IS-IS router: three vendors, three LSPs, and a bug in FRR
In the previous post, one LSP with both the attached bit and the overload bit gave a default route on Junos and FRR, and none on SR OS. I left two questions open: does every vendor keep the attached bit when overload is set, and what happens when the access router has several exits, which is the real use of a drain? And the first post tested only one sender, SR OS.
