diff --git a/archetype/src/main/resources/archetype-resources/src/main/resources/default-regex-filters.txt b/archetype/src/main/resources/archetype-resources/src/main/resources/default-regex-filters.txt
index 389ef587b..36e8dfcb5 100644
--- a/archetype/src/main/resources/archetype-resources/src/main/resources/default-regex-filters.txt
+++ b/archetype/src/main/resources/archetype-resources/src/main/resources/default-regex-filters.txt
@@ -14,11 +14,23 @@
 # of services running on the crawling machine (e.g., Elasticsearch,
 # Storm)
 #
-# - exclude localhost and loop-back addresses
+# NOTE: these rules judge the bytes of the URL only. A host name which
+# resolves into one of the ranges below is not caught here; the IP
+# address filter (http.filter.ipaddress.exclude) sees the address the
+# fetcher actually connects to and is the authoritative check.
+#
+# - exclude localhost and loop-back addresses, including the abbreviated
+#   and integer IPv4 forms the resolver maps to 127.0.0.1
 #     http://localhost:8080
 #     http://127.0.0.1/ .. http://127.255.255.255/
+#     http://127.1/
+#     http://2130706433/
 #     http://[::1]/
--^https?://(?:localhost|127(?:\.(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))){3}|\[::1\])(?::\d+)?(?:/|$)
+-^https?://(?:localhost|127(?:\.(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))){0,3}|\[::1\])(?::\d+)?(?:/|$)
+#     the integer form of an IPv4 address resolves to the address it encodes
+#     (e.g. http://2130706433/ is 127.0.0.1); such URLs are blocked outright,
+#     a crawl that needs one can rewrite it to its dotted form
+-^https?://\d{1,10}(?::\d+)?(?:/|$)
 #
 # - exclude private IP address spaces
 #     10.0.0.0/8
@@ -27,6 +39,14 @@
 -^https?://(?:192\.168(?:\.(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))){2})(?::\d+)?(?:/|$)
 #     172.16.0.0/12
 -^https?://(?:172\.(?:1[6789]|2[0-9]|3[01])(?:\.(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))){2})(?::\d+)?(?:/|$)
+#     169.254.0.0/16 (link-local, e.g. cloud instance metadata services)
+-^https?://(?:169\.254(?:\.(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))){2})(?::\d+)?(?:/|$)
+#     100.64.0.0/10 (carrier-grade NAT)
+-^https?://(?:100\.(?:6[0-4]|[7-9][0-9]|1[01][0-9]|12[0-7])(?:\.(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))){2})(?::\d+)?(?:/|$)
+#     0.0.0.0/8 ("this network")
+-^https?://(?:0(?:\.(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))){1,3})(?::\d+)?(?:/|$)
+#     IPv6 unique-local (fc00::/7) and link-local (fe80::/10) addresses
+-^https?://\[(?:f[cd][0-9a-f]{2}|fe[89ab][0-9a-f]):[0-9a-f:]+\](?::\d+)?(?:/|$)
 
 # accept anything else
 +.
diff --git a/core/src/main/resources/crawler-default.yaml b/core/src/main/resources/crawler-default.yaml
index 6945b2c4c..17b49dd9a 100644
--- a/core/src/main/resources/crawler-default.yaml
+++ b/core/src/main/resources/crawler-default.yaml
@@ -161,8 +161,12 @@ config:
   #   - "linklocal" (matches InetAddress.isLinkLocalAddress())
   # Only addresses matching an include rule are fetched (empty means all are
   # allowed), addresses matching an exclude rule are always blocked.
-  # http.filter.ipaddress.include:
-  # http.filter.ipaddress.exclude: "localhost,sitelocal,linklocal"
+  # The exclude list is enabled by default: a fetched page decides which hosts
+  # the fetcher connects to, and loopback, private and link-local ranges host
+  # unauthenticated services (e.g. cloud instance metadata) which a public
+  # index must not leak into. Set http.filter.ipaddress.include to any value
+  # (e.g. "0.0.0.0/0") and leave the exclude list empty to crawl an intranet.
+  http.filter.ipaddress.exclude: "localhost,sitelocal,linklocal,100.64.0.0/10,fd00::/8"
 
   # Allow all if robots.txt cannot be parsed due to code 403 (Forbidden):
   http.robots.403.allow: true
diff --git a/core/src/test/java/org/apache/stormcrawler/filtering/DefaultRegexFiltersPrivateRangeTest.java b/core/src/test/java/org/apache/stormcrawler/filtering/DefaultRegexFiltersPrivateRangeTest.java
new file mode 100644
index 000000000..3ec60a43b
--- /dev/null
+++ b/core/src/test/java/org/apache/stormcrawler/filtering/DefaultRegexFiltersPrivateRangeTest.java
@@ -0,0 +1,132 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to you under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.stormcrawler.filtering;
+
+import com.fasterxml.jackson.databind.node.ArrayNode;
+import com.fasterxml.jackson.databind.node.JsonNodeFactory;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.charset.StandardCharsets;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import org.apache.stormcrawler.Metadata;
+import org.apache.stormcrawler.filtering.regex.RegexURLFilter;
+import org.apache.stormcrawler.util.URLUtil;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+/**
+ * The private-range rules shipped in the archetype default-regex-filters.txt, applied to hosts the
+ * JVM resolver maps into loopback, link-local and other non-routable space.
+ */
+class DefaultRegexFiltersPrivateRangeTest {
+
+    private static final List<String> ARCHETYPE_RULES = new ArrayList<>();
+
+    @BeforeAll
+    static void loadShippedRules() throws IOException {
+        try (InputStream in =
+                DefaultRegexFiltersPrivateRangeTest.class.getResourceAsStream(
+                        "/default-regex-filters.txt")) {
+            Assertions.assertNotNull(in, "the archetype rules file must be on the test classpath");
+            for (String line :
+                    new String(in.readAllBytes(), StandardCharsets.UTF_8).split("\\r?\\n")) {
+                String trimmed = line.trim();
+                if (!trimmed.isEmpty() && !trimmed.startsWith("#")) {
+                    ARCHETYPE_RULES.add(trimmed);
+                }
+            }
+        }
+    }
+
+    private URLFilter createFilter() {
+        ObjectNode filterParams = new ObjectNode(JsonNodeFactory.instance);
+        ArrayNode rules = filterParams.putArray("urlFilters");
+        for (String rule : ARCHETYPE_RULES) {
+            rules.add(rule);
+        }
+        RegexURLFilter filter = new RegexURLFilter();
+        Map<String, Object> conf = new HashMap<>();
+        filter.configure(conf, filterParams);
+        return filter;
+    }
+
+    private void assertRejected(URLFilter filter, String url) throws MalformedURLException {
+        URL source = URLUtil.toURL("http://www.example.com/index.html");
+        Assertions.assertNull(filter.filter(source, new Metadata(), url), url);
+    }
+
+    @Test
+    void dottedQuadFormsAreRejected() throws MalformedURLException {
+        URLFilter filter = createFilter();
+        assertRejected(filter, "http://127.0.0.1/");
+        assertRejected(filter, "http://10.0.0.5/");
+        assertRejected(filter, "http://192.168.1.1/");
+        assertRejected(filter, "http://172.16.0.1/");
+    }
+
+    @Test
+    void otherNonRoutableRangesAreRejected() throws MalformedURLException {
+        URLFilter filter = createFilter();
+        assertRejected(filter, "http://169.254.169.254/");
+        assertRejected(filter, "http://100.64.0.1/");
+        assertRejected(filter, "http://100.127.255.254/");
+        assertRejected(filter, "http://0.0.0.0/");
+        assertRejected(filter, "http://[fd00::1]/");
+        assertRejected(filter, "http://[fe80::1]/");
+    }
+
+    /** Both host forms are resolved to 127.0.0.1 by InetAddress.getByName. */
+    @Test
+    void abbreviatedAndIntegerLoopbackFormsAreRejected() throws MalformedURLException {
+        URLFilter filter = createFilter();
+        assertRejected(filter, "http://127.1/");
+        assertRejected(filter, "http://2130706433/");
+    }
+
+    /** The fetcher must not reach private space at all: the shipped IP filter default. */
+    @Test
+    void ipFilterExcludeListIsShippedEnabled() throws Exception {
+        Map<String, Object> defaults =
+                org.apache.storm.utils.Utils.findAndReadConfigFile("crawler-default.yaml", false);
+        Map<String, Object> conf = org.apache.stormcrawler.util.ConfUtils.extractConfigElement(defaults);
+        String exclude =
+                org.apache.stormcrawler.util.ConfUtils.getString(
+                        conf, "http.filter.ipaddress.exclude", null);
+        Assertions.assertNotNull(
+                exclude, "http.filter.ipaddress.exclude must be enabled in crawler-default.yaml");
+        org.apache.stormcrawler.protocol.IPFilterRules ipFilter =
+                new org.apache.stormcrawler.protocol.IPFilterRules(conf);
+        Assertions.assertFalse(ipFilter.isEmpty());
+        Assertions.assertFalse(
+                ipFilter.accept(java.net.InetAddress.getByName("169.254.169.254")),
+                "link-local must be excluded by the shipped default");
+        Assertions.assertFalse(
+                ipFilter.accept(java.net.InetAddress.getByName("127.0.0.1")),
+                "loopback must be excluded by the shipped default");
+        Assertions.assertTrue(
+                ipFilter.accept(java.net.InetAddress.getByName("140.211.11.131")),
+                "public addresses must still be accepted");
+    }
+}
diff --git a/core/src/test/resources/default-regex-filters.txt b/core/src/test/resources/default-regex-filters.txt
index cfd2979e7..36e8dfcb5 100644
--- a/core/src/test/resources/default-regex-filters.txt
+++ b/core/src/test/resources/default-regex-filters.txt
@@ -3,11 +3,50 @@
 
 # skip image and other suffixes we can't parse or are not likely to be relevant
 # if you want to crawl images or videos or archives then you should comment out this line
--(?i)\.(gif|jpg|png|ico|css|sit|eps|wmf|zip|gz|rpm|tgz|mov|exe|jpeg|bmp|js|mpg|mp3|mp4)(\?|&|$)
+-(?i)\.(apk|deb|cab|iso|gif|jpg|png|svg|ico|css|sit|eps|wmf|rar|tar|jar|zip|gz|bz2|rpm|tgz|mov|exe|jpeg|jpe|bmp|js|mpg|mp3|mp4|m4a|ogv|kml|wmv|swf|flv|mkv|m4v|webm|ra|wma|wav|avi|xspf|m3u)(\?|&|$)
 
 # skip URLs with slash-delimited segment that repeats 3+ times, to break loops
-# very time-consuming : use only if necessary
+# very time-consuming : use BasicURLFilter instead
 # -.*(/[^/]+)/[^/]+\1/[^/]+\1/
 
+# exclude localhost and equivalents to avoid that information
+# can be leaked by placing faked links pointing to web interfaces
+# of services running on the crawling machine (e.g., Elasticsearch,
+# Storm)
+#
+# NOTE: these rules judge the bytes of the URL only. A host name which
+# resolves into one of the ranges below is not caught here; the IP
+# address filter (http.filter.ipaddress.exclude) sees the address the
+# fetcher actually connects to and is the authoritative check.
+#
+# - exclude localhost and loop-back addresses, including the abbreviated
+#   and integer IPv4 forms the resolver maps to 127.0.0.1
+#     http://localhost:8080
+#     http://127.0.0.1/ .. http://127.255.255.255/
+#     http://127.1/
+#     http://2130706433/
+#     http://[::1]/
+-^https?://(?:localhost|127(?:\.(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))){0,3}|\[::1\])(?::\d+)?(?:/|$)
+#     the integer form of an IPv4 address resolves to the address it encodes
+#     (e.g. http://2130706433/ is 127.0.0.1); such URLs are blocked outright,
+#     a crawl that needs one can rewrite it to its dotted form
+-^https?://\d{1,10}(?::\d+)?(?:/|$)
+#
+# - exclude private IP address spaces
+#     10.0.0.0/8
+-^https?://(?:10(?:\.(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))){3})(?::\d+)?(?:/|$)
+#     192.168.0.0/16
+-^https?://(?:192\.168(?:\.(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))){2})(?::\d+)?(?:/|$)
+#     172.16.0.0/12
+-^https?://(?:172\.(?:1[6789]|2[0-9]|3[01])(?:\.(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))){2})(?::\d+)?(?:/|$)
+#     169.254.0.0/16 (link-local, e.g. cloud instance metadata services)
+-^https?://(?:169\.254(?:\.(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))){2})(?::\d+)?(?:/|$)
+#     100.64.0.0/10 (carrier-grade NAT)
+-^https?://(?:100\.(?:6[0-4]|[7-9][0-9]|1[01][0-9]|12[0-7])(?:\.(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))){2})(?::\d+)?(?:/|$)
+#     0.0.0.0/8 ("this network")
+-^https?://(?:0(?:\.(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))){1,3})(?::\d+)?(?:/|$)
+#     IPv6 unique-local (fc00::/7) and link-local (fe80::/10) addresses
+-^https?://\[(?:f[cd][0-9a-f]{2}|fe[89ab][0-9a-f]):[0-9a-f:]+\](?::\d+)?(?:/|$)
+
 # accept anything else
 +.
diff --git a/external/opensearch/archetype/src/main/resources/archetype-resources/src/main/resources/default-regex-filters.txt b/external/opensearch/archetype/src/main/resources/archetype-resources/src/main/resources/default-regex-filters.txt
index 389ef587b..36e8dfcb5 100644
--- a/external/opensearch/archetype/src/main/resources/archetype-resources/src/main/resources/default-regex-filters.txt
+++ b/external/opensearch/archetype/src/main/resources/archetype-resources/src/main/resources/default-regex-filters.txt
@@ -14,11 +14,23 @@
 # of services running on the crawling machine (e.g., Elasticsearch,
 # Storm)
 #
-# - exclude localhost and loop-back addresses
+# NOTE: these rules judge the bytes of the URL only. A host name which
+# resolves into one of the ranges below is not caught here; the IP
+# address filter (http.filter.ipaddress.exclude) sees the address the
+# fetcher actually connects to and is the authoritative check.
+#
+# - exclude localhost and loop-back addresses, including the abbreviated
+#   and integer IPv4 forms the resolver maps to 127.0.0.1
 #     http://localhost:8080
 #     http://127.0.0.1/ .. http://127.255.255.255/
+#     http://127.1/
+#     http://2130706433/
 #     http://[::1]/
--^https?://(?:localhost|127(?:\.(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))){3}|\[::1\])(?::\d+)?(?:/|$)
+-^https?://(?:localhost|127(?:\.(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))){0,3}|\[::1\])(?::\d+)?(?:/|$)
+#     the integer form of an IPv4 address resolves to the address it encodes
+#     (e.g. http://2130706433/ is 127.0.0.1); such URLs are blocked outright,
+#     a crawl that needs one can rewrite it to its dotted form
+-^https?://\d{1,10}(?::\d+)?(?:/|$)
 #
 # - exclude private IP address spaces
 #     10.0.0.0/8
@@ -27,6 +39,14 @@
 -^https?://(?:192\.168(?:\.(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))){2})(?::\d+)?(?:/|$)
 #     172.16.0.0/12
 -^https?://(?:172\.(?:1[6789]|2[0-9]|3[01])(?:\.(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))){2})(?::\d+)?(?:/|$)
+#     169.254.0.0/16 (link-local, e.g. cloud instance metadata services)
+-^https?://(?:169\.254(?:\.(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))){2})(?::\d+)?(?:/|$)
+#     100.64.0.0/10 (carrier-grade NAT)
+-^https?://(?:100\.(?:6[0-4]|[7-9][0-9]|1[01][0-9]|12[0-7])(?:\.(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))){2})(?::\d+)?(?:/|$)
+#     0.0.0.0/8 ("this network")
+-^https?://(?:0(?:\.(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))){1,3})(?::\d+)?(?:/|$)
+#     IPv6 unique-local (fc00::/7) and link-local (fe80::/10) addresses
+-^https?://\[(?:f[cd][0-9a-f]{2}|fe[89ab][0-9a-f]):[0-9a-f:]+\](?::\d+)?(?:/|$)
 
 # accept anything else
 +.
diff --git a/external/solr/archetype/src/main/resources/archetype-resources/src/main/resources/default-regex-filters.txt b/external/solr/archetype/src/main/resources/archetype-resources/src/main/resources/default-regex-filters.txt
index 389ef587b..36e8dfcb5 100644
--- a/external/solr/archetype/src/main/resources/archetype-resources/src/main/resources/default-regex-filters.txt
+++ b/external/solr/archetype/src/main/resources/archetype-resources/src/main/resources/default-regex-filters.txt
@@ -14,11 +14,23 @@
 # of services running on the crawling machine (e.g., Elasticsearch,
 # Storm)
 #
-# - exclude localhost and loop-back addresses
+# NOTE: these rules judge the bytes of the URL only. A host name which
+# resolves into one of the ranges below is not caught here; the IP
+# address filter (http.filter.ipaddress.exclude) sees the address the
+# fetcher actually connects to and is the authoritative check.
+#
+# - exclude localhost and loop-back addresses, including the abbreviated
+#   and integer IPv4 forms the resolver maps to 127.0.0.1
 #     http://localhost:8080
 #     http://127.0.0.1/ .. http://127.255.255.255/
+#     http://127.1/
+#     http://2130706433/
 #     http://[::1]/
--^https?://(?:localhost|127(?:\.(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))){3}|\[::1\])(?::\d+)?(?:/|$)
+-^https?://(?:localhost|127(?:\.(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))){0,3}|\[::1\])(?::\d+)?(?:/|$)
+#     the integer form of an IPv4 address resolves to the address it encodes
+#     (e.g. http://2130706433/ is 127.0.0.1); such URLs are blocked outright,
+#     a crawl that needs one can rewrite it to its dotted form
+-^https?://\d{1,10}(?::\d+)?(?:/|$)
 #
 # - exclude private IP address spaces
 #     10.0.0.0/8
@@ -27,6 +39,14 @@
 -^https?://(?:192\.168(?:\.(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))){2})(?::\d+)?(?:/|$)
 #     172.16.0.0/12
 -^https?://(?:172\.(?:1[6789]|2[0-9]|3[01])(?:\.(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))){2})(?::\d+)?(?:/|$)
+#     169.254.0.0/16 (link-local, e.g. cloud instance metadata services)
+-^https?://(?:169\.254(?:\.(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))){2})(?::\d+)?(?:/|$)
+#     100.64.0.0/10 (carrier-grade NAT)
+-^https?://(?:100\.(?:6[0-4]|[7-9][0-9]|1[01][0-9]|12[0-7])(?:\.(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))){2})(?::\d+)?(?:/|$)
+#     0.0.0.0/8 ("this network")
+-^https?://(?:0(?:\.(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))){1,3})(?::\d+)?(?:/|$)
+#     IPv6 unique-local (fc00::/7) and link-local (fe80::/10) addresses
+-^https?://\[(?:f[cd][0-9a-f]{2}|fe[89ab][0-9a-f]):[0-9a-f:]+\](?::\d+)?(?:/|$)
 
 # accept anything else
 +.