-.\" $OpenBSD: options.4,v 1.47 2000/03/02 10:50:28 art Exp $
+.\" $OpenBSD: options.4,v 1.48 2000/03/02 13:44:33 aaron Exp $
.\" $NetBSD: options.4,v 1.21 1997/06/25 03:13:00 thorpej Exp $
.\"
.\" Copyright (c) 1998 Theo de Raadt
.Em TCP_SACK .
.It Cd option TCP_SIGNATURE
Turns on support for the TCP MD5 Signature option (RFC 2385). This is used by
-Internet backdone routers to provide per-packet authentication for the TCP
+Internet backbone routers to provide per-packet authentication for the TCP
packets used to communicate BGP routing information. You will also need a
routing daemon that supports this option in order to actually use it.
.It Cd option IPFILTER