diff --git a/client/d4.c b/client/d4.c
index 05dc56c..9df584b 100644
--- a/client/d4.c
+++ b/client/d4.c
@@ -10,6 +10,35 @@
 #include <errno.h>
 
 #include "d4.h"
+//
+int d4_check_config(d4_t* d4)
+{
+    // TODO implement other sources, file, fifo, unix_socket ...
+    if (strlen(d4->conf[SOURCE]) > strlen(STDIN)) {
+        if (!strncmp(d4->conf[SOURCE],STDIN, strlen(STDIN))) {
+            d4->source.fd = STDIN_FILENO;
+        }
+    }
+
+    //TODO implement other destinations file, fifo unix_socket ...
+    if (strlen(d4->conf[DESTINATION]) > strlen(STDOUT)) {
+        if (!strncmp(d4->conf[DESTINATION],STDOUT, strlen(STDOUT))) {
+            d4->destination.fd = STDOUT_FILENO;
+        }
+    }
+    d4->snaplen  = atoi(d4->conf[SNAPLEN]);
+    if ((d4->snaplen < 0)  || (d4->snaplen > MAXSNAPLEN)) {
+        d4->snaplen = 0;
+    }
+
+    printf("TEST snaplen %d stdin %d stdout %d\n", d4->snaplen, STDIN_FILENO, STDOUT_FILENO);
+    //FIXME Check other parameters
+    if (( d4->destination.fd > 0 ) && ( d4->snaplen >0 )) {
+        return 1;
+    }
+    return -1;
+}
+
 //Returns -1 on error, 0 otherwise
 int d4_load_config(d4_t* d4)
 {
@@ -30,7 +59,7 @@ int d4_load_config(d4_t* d4)
             }
         }
     }
-    return -1;
+    return d4_check_config(d4);
 }
 
 void usage(void)
diff --git a/client/d4.h b/client/d4.h
index 3ede9e2..cc33295 100644
--- a/client/d4.h
+++ b/client/d4.h
@@ -6,6 +6,10 @@
 #define SZCONFVALUE 1024
 #define SZERRVALUE 1024
 
+#define STDIN "stdin"
+#define STDOUT "stdout"
+#define MAXSNAPLEN 65535
+
 #define INSERT_ERROR(...) do { \
     if (d4->err_idx < NERRORS) \
         snprintf(d4->errors[d4->err_idx],SZERRVALUE,__VA_ARGS__); \