Index: src/java/org/apache/nutch/crawl/LinkDb.java
===================================================================
--- src/java/org/apache/nutch/crawl/LinkDb.java	(revision 2764)
+++ src/java/org/apache/nutch/crawl/LinkDb.java	(working copy)
@@ -48,6 +48,7 @@
   public static final Logger LOG = LoggerFactory.getLogger(LinkDb.class);
 
   public static final String IGNORE_INTERNAL_LINKS = "db.ignore.internal.links";
+  public static final String IGNORE_EXTERNAL_LINKS = "db.ignore.external.links";
 
   public static final String CURRENT_NAME = "current";
   public static final String LOCK_NAME = ".locked";
@@ -54,6 +55,7 @@
 
   private int maxAnchorLength;
   private boolean ignoreInternalLinks;
+  private boolean ignoreExternalLinks;
   private URLFilters urlFilters;
   private URLNormalizers urlNormalizers;
   
@@ -66,6 +68,8 @@
   public void configure(JobConf job) {
     maxAnchorLength = job.getInt("db.max.anchor.length", 100);
     ignoreInternalLinks = job.getBoolean(IGNORE_INTERNAL_LINKS, true);
+    ignoreExternalLinks = job.getBoolean(IGNORE_EXTERNAL_LINKS, false);
+
     if (job.getBoolean(LinkDbFilter.URL_FILTERING, false)) {
       urlFilters = new URLFilters(job);
     }
@@ -110,6 +114,12 @@
           continue;                               // skip it
         }
       }
+      if (ignoreExternalLinks) {
+        String toHost = getHost(toUrl);
+        if (toHost == null || !toHost.equals(fromHost)) { // external link
+          continue;                               // skip it
+        }
+      }
       if (urlNormalizers != null) {
         try {
           toUrl = urlNormalizers.normalize(toUrl, URLNormalizers.SCOPE_LINKDB); // normalize the url