diff --git a/extras/pcapcli/setup.tracefilter b/extras/pcapcli/setup.tracefilter
index e6c86298c84..db07a0e4224 100644
--- a/extras/pcapcli/setup.tracefilter
+++ b/extras/pcapcli/setup.tracefilter
@@ -17,4 +17,6 @@ packet-generator new {
     }
 }
 
-classify filter trace mask l3 ip4 src match l3 ip4 src 192.168.1.15
+comment { Pick one, uncomment, and "pcap rx ..." or "trace add pg-input ..." }
+comment { classify filter trace mask l3 ip4 src match l3 ip4 src 192.168.1.15 }
+comment { classify filter pcap mask l3 ip4 src match l3 ip4 src 192.168.1.15 }
diff --git a/src/vnet/classify/vnet_classify.c b/src/vnet/classify/vnet_classify.c
index b02a5dc6e5e..5843c36f139 100755
--- a/src/vnet/classify/vnet_classify.c
+++ b/src/vnet/classify/vnet_classify.c
@@ -1744,6 +1744,10 @@ classify_filter_command_fn (vlib_main_t * vm,
   if (sw_if_index == ~0 && pkt_trace == 0 && pcap == 0)
     return clib_error_return (0, "Must specify trace, pcap or interface...");
 
+  if (pkt_trace && pcap)
+    return clib_error_return
+      (0, "Packet trace and pcap are mutually exclusive...");
+
   if (pkt_trace && sw_if_index != ~0)
     return clib_error_return (0, "Packet trace filter is per-system");
 
diff --git a/src/vnet/interface_cli.c b/src/vnet/interface_cli.c
index 8fb315b4846..2e5714c3c0f 100644
--- a/src/vnet/interface_cli.c
+++ b/src/vnet/interface_cli.c
@@ -1954,7 +1954,7 @@ vnet_pcap_dispatch_trace_configure (vnet_pcap_dispatch_trace_args_t * a)
 
   /* Classify filter specified, but no classify filter configured */
   if ((a->rx_enable + a->tx_enable + a->drop_enable) && a->filter &&
-      (set->table_indices[0] == ~0))
+      (set->table_indices == 0 || set->table_indices[0] == ~0))
     return VNET_API_ERROR_NO_SUCH_LABEL;
 
   if (a->rx_enable + a->tx_enable + a->drop_enable)