diff --git a/filter/filter.c b/filter/filter.c
index ed0b21bc..d9c98872 100644
--- a/filter/filter.c
+++ b/filter/filter.c
@@ -482,3 +482,41 @@ filter_commit(struct config *new, struct config *old)
 	break;
     }
 }
+
+void filters_dump_all(void)
+{
+  struct symbol *sym;
+  WALK_LIST(sym, config->symbols) {
+    switch (sym->class) {
+      case SYM_FILTER:
+	debug("Named filter %s:\n", sym->name);
+	f_dump_line(sym->filter->root, 1);
+	break;
+      case SYM_FUNCTION:
+	debug("Function %s:\n", sym->name);
+	f_dump_line(sym->function, 1);
+	break;
+      case SYM_PROTO:
+	{
+	  debug("Protocol %s:\n", sym->name);
+	  struct channel *c;
+	  WALK_LIST(c, sym->proto->proto->channels) {
+	    debug(" Channel %s (%s) IMPORT", c->name, net_label[c->net_type]);
+	    if (c->in_filter == FILTER_ACCEPT)
+	      debug(" ALL\n");
+	    else if (c->in_filter == FILTER_REJECT)
+	      debug(" NONE\n");
+	    else if (c->in_filter == FILTER_UNDEF)
+	      debug(" UNDEF\n");
+	    else if (c->in_filter->sym) {
+	      ASSERT(c->in_filter->sym->filter == c->in_filter);
+	      debug(" named filter %s\n", c->in_filter->sym->name);
+	    } else {
+	      debug("\n");
+	      f_dump_line(c->in_filter->root, 2);
+	    }
+	  }
+	}
+    }
+  }
+}
diff --git a/filter/filter.h b/filter/filter.h
index 36b63e7c..9d997efb 100644
--- a/filter/filter.h
+++ b/filter/filter.h
@@ -64,9 +64,11 @@ int f_same(const struct f_line *f1, const struct f_line *f2);
 
 void filter_commit(struct config *new, struct config *old);
 
+void filters_dump_all(void);
+
 #define FILTER_ACCEPT NULL
-#define FILTER_REJECT ((void *) 1)
-#define FILTER_UNDEF  ((void *) 2)	/* Used in BGP */
+#define FILTER_REJECT ((struct filter *) 1)
+#define FILTER_UNDEF  ((struct filter *) 2)	/* Used in BGP */
 
 #define FF_SILENT 2			/* Silent filter execution */
 
diff --git a/nest/config.Y b/nest/config.Y
index 430c9f29..e97b8fb3 100644
--- a/nest/config.Y
+++ b/nest/config.Y
@@ -731,6 +731,8 @@ CF_CLI(DUMP ROUTES,,, [[Dump routing table]])
 { rt_dump_all(); cli_msg(0, ""); } ;
 CF_CLI(DUMP PROTOCOLS,,, [[Dump protocol information]])
 { protos_dump_all(); cli_msg(0, ""); } ;
+CF_CLI(DUMP FILTER ALL,,, [[Dump all filters in linearized form]])
+{ filters_dump_all(); cli_msg(0, ""); } ;
 
 CF_CLI(EVAL, term, <expr>, [[Evaluate an expression]])
 { cmd_eval(f_linearize($2)); } ;