[FROG] IS-IS MTU in FRR

Hi all. As I've been unable to find anyone in the (NOG) community who has had any experience running IS-IS on FRR, I figured I'd set it all up and see how well it works. My first major road block is the below: 2020/03/21 03:12:36 ISIS: isis_send_pdu_bcast: sock_buff size 8192 is less than output pdu size 9014 on circuit em0 2020/03/21 03:12:36 ISIS: [EC 67108865] ISIS-Adj (1): Send L2 IIH on em0 failed I've been fiddling with all manner of MTU commands/settings both in zebra.conf and isisd.conf, but they all don't seem to be supported. Does anyone know how we can fix CLNS/IS-IS MTU on FRR? I'm running FRR 7.3 on FreeBSD-12.1. All help appreciated. Mark.