Hi all. I posted the below in 2020 about IS-IS in FRR (7.3, at the time): https://seclists.org/nanog/2020/Apr/226 I gave up and moved back to Quagga with OSPF. I decided to try again today, with FRR 8.5, on FreeBSD-13.1-RELEASE-p6. Things seem to have taken a major step back since then. I can't even get an adjacency going with a Cisco IOS XE router: 2023/03/31 07:12:01 ISIS: [WDVAD-TY6HY] ISIS-LFA: failed to unregister RLFA with LDP 2023/03/31 07:12:01 ISIS: [WDVAD-TY6HY] ISIS-LFA: failed to unregister RLFA with LDP 2023/03/31 07:12:01 ISIS: [WDVAD-TY6HY] ISIS-LFA: failed to unregister RLFA with LDP 2023/03/31 07:12:01 ISIS: [YDRGH-0DJ94] Opened BPF device /dev/bpf0 2023/03/31 07:12:01 ISIS: [QJWNQ-3FFKM] BPF buffer len = 4096 2023/03/31 07:12:01 ISIS: [V3AHD-XE2Z5] failed to set BPF buffer len (4096 to 9000) 2023/03/31 07:12:01 ISIS: [W02G1-H56T1] IS-IS bpf: could not transmit packet on em0: Input/output error 2023/03/31 07:12:01 ISIS: [G7ZA5-AT06A][EC 67108865] ISIS-Adj (1): Send L2 IIH on em0 failed 2023/03/31 07:12:04 ISIS: [W02G1-H56T1] IS-IS bpf: could not transmit packet on em0: Input/output error 2023/03/31 07:12:04 ISIS: [G7ZA5-AT06A][EC 67108865] ISIS-Adj (1): Send L2 IIH on em0 failed 2023/03/31 07:12:07 ISIS: [W02G1-H56T1] IS-IS bpf: could not transmit packet on em0: Input/output error 2023/03/31 07:12:07 ISIS: [G7ZA5-AT06A][EC 67108865] ISIS-Adj (1): Send L2 IIH on em0 failed Thoughts? Mark.