Just as a data point, Solaris 9 client uses initial seq. no. 2.
/fc
start gss seq no at 1; netapp doesn't accept seq no 0.
--- linux-2.5.75.0/net/sunrpc/auth_gss/auth_gss.c
+++ linux-2.5.75.1/net/sunrpc/auth_gss/auth_gss.c
@@ -236,7 +236,7 @@
goto err;
}
ctx->gc_proc = RPC_GSS_PROC_DATA;
- ctx->gc_seq = 0;
+ ctx->gc_seq = 1; /* NetApp 6.4R1 doesn't accept seq. no. 0 */
spin_lock_init(&ctx->gc_seq_lock);
atomic_set(&ctx->count,1);