@@ -8,7 +8,7 @@
rpc.gssd \- RPCSEC_GSS daemon
.SH SYNOPSIS
.B rpc.gssd
-.RB [ \-DfMnlvr ]
+.RB [ \-DGfMnlvr ]
.RB [ \-k
.IR keytab ]
.RB [ \-p
@@ -20,8 +20,9 @@ rpc.gssd \- RPCSEC_GSS daemon
.RB [ \-R
.IR realm ]
.SH INTRODUCTION
-The RPCSEC_GSS protocol, defined in RFC 5403, is used to provide
-strong security for RPC-based protocols such as NFS.
+The RPCSEC_GSS version 1 protocol defined in RFC 5403, and the RPCSEC_GSS version 3 protocol defined in RFC 7861, are used to provide strong security for RPC-based protocols such as NFS.
+.P
+RPCSEC_GSS version 3 supports all of RPCSEC_GSS version 1 features, and provides support for communicating additional authorization and authentication information to a server.
.P
Before exchanging RPC requests using RPCSEC_GSS, an RPC client must
establish a GSS
@@ -218,6 +219,13 @@ can introduce a security vulnerability, so it is recommended that
not be used, and that canonical names always be used when requesting
services.
.TP
+.B \-G
+For GSS context initialization, GSS version 3 is normally tried first, and if the server reports an RPC level error, then GSS version 1 is tried. The negotiated GSS version is then passed to the kernel. This happens for each GSS context initilaization request.
+
+If the kernel does not support the GSS version downcall, the mount will fail.
+
+If .B \-G is present, the GSS version will not be passed to the kernel, and GSS version 3 will not be attempted; all calls will use GSS version 1.
+.TP
.B -f
Runs
.B rpc.gssd