diff --git a/src/addrdb.h b/src/addrdb.h
--- a/src/addrdb.h
+++ b/src/addrdb.h
@@ -10,10 +10,10 @@
 #include <net_types.h> // For banmap_t
 #include <serialize.h>
 
-#include <map>
 #include <string>
+#include <vector>
 
-class CSubNet;
+class CAddress;
 class CAddrMan;
 class CDataStream;
 class CChainParams;
@@ -70,4 +70,14 @@
     bool Read(banmap_t &banSet);
 };
 
+/**
+ * Dump the anchor IP address database (anchors.dat)
+ *
+ * Anchors are last known outgoing block-relay-only peers that are
+ * tried to re-connect to on startup.
+ */
+void DumpAnchors(const CChainParams &chainParams,
+                 const fs::path &anchors_db_path,
+                 const std::vector<CAddress> &anchors);
+
 #endif // BITCOIN_ADDRDB_H
diff --git a/src/addrdb.cpp b/src/addrdb.cpp
--- a/src/addrdb.cpp
+++ b/src/addrdb.cpp
@@ -9,6 +9,7 @@
 #include <chainparams.h>
 #include <clientversion.h>
 #include <hash.h>
+#include <logging/timer.h>
 #include <random.h>
 #include <streams.h>
 #include <tinyformat.h>
@@ -153,3 +154,12 @@
     }
     return ret;
 }
+
+void DumpAnchors(const CChainParams &chainParams,
+                 const fs::path &anchors_db_path,
+                 const std::vector<CAddress> &anchors) {
+    LOG_TIME_SECONDS(strprintf(
+        "Flush %d outbound block-relay-only peer addresses to anchors.dat",
+        anchors.size()));
+    SerializeFileDB(chainParams, "anchors", anchors_db_path, anchors);
+}