The l command displays, in hexadecimal, the link fields of the frame FID.
l fid
frmn:frmp:npcf:clnk= nncf: number of next contiguous frame(s) frmn: forward link frmp: backward link npcf: number of prior contiguous frame(s) clnk: core link
New values for the fields can then be entered, separated by commas, with an empty field to leave a field unchanged.