--- httpd-2.2.18-original/modules/proxy/mod_proxy.c	2010-10-07 20:51:18.000000000 +0200
+++ httpd-2.2.18-original/modules/proxy/mod_proxy.c	2011-05-19 13:08:18.012828504 +0200
@@ -101,6 +101,15 @@ 
             return "TTL must be at least one second";
         worker->ttl = apr_time_from_sec(ival);
     }
+    else if (!strcasecmp(key, "dnsto")) {
+        /* Time in seconds that will cause a new dns lookup
+         * for the connection
+         */
+        ival = atoi(val);
+        if (ival < 1)
+            return "DNSTO must be at least one second";
+        worker->dnsto = apr_time_from_sec(ival);
+    }
     else if (!strcasecmp(key, "min")) {
         /* Initial number of connections to remote
          */
--- httpd-2.2.18-original/modules/proxy/mod_proxy.h	2010-10-07 20:51:18.000000000 +0200
+++ httpd-2.2.18-original/modules/proxy/mod_proxy.h	2011-05-19 13:09:41.758940503 +0200
@@ -358,6 +358,7 @@ 
     char            disablereuse_set;
     apr_interval_time_t conn_timeout;
     char            conn_timeout_set;
+    apr_interval_time_t dnsto;	/* Timeout for the stored ip address to be looked up again */
 };
 
 /*
--- httpd-2.2.18-original/modules/proxy/proxy_util.c	2010-08-25 16:10:14.000000000 +0200
+++ httpd-2.2.18-original/modules/proxy/proxy_util.c	2011-05-19 13:14:09.241028504 +0200
@@ -49,6 +49,7 @@ 
 static int proxy_match_domainname(struct dirconn_entry *This, request_rec *r);
 static int proxy_match_hostname(struct dirconn_entry *This, request_rec *r);
 static int proxy_match_word(struct dirconn_entry *This, request_rec *r);
+static char *get_addr(char *buf, apr_sockaddr_t *sa);
 
 APR_IMPLEMENT_OPTIONAL_HOOK_RUN_ALL(proxy, PROXY, int, create_req,
                                    (request_rec *r, request_rec *pr), (r, pr),
@@ -2026,14 +2027,62 @@ 
                                                proxy_conn_rec *conn,
                                                server_rec *s)
 {
+    char old_address[512];
+    char new_address[512];
+    int dnsto;
+
     ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s,
                  "proxy: %s: has released connection for (%s)",
                  proxy_function, conn->worker->hostname);
-    connection_cleanup(conn);
+
+    dnsto = apr_time_sec(conn->worker->dnsto);
+    if (dnsto) {
+        apr_status_t return_value;
+        const char *hostname = conn->worker->hostname;
+        const apr_port_t port = conn->worker->port;
+        apr_sockaddr_t *old_sock_addr = conn->addr;
+        apr_sockaddr_t *new_sock_addr;
+        apr_pool_t *pool;
+        return_value = apr_pool_create(&pool, conn->pool);
+        apr_sockaddr_info_get(&new_sock_addr, hostname, APR_UNSPEC, port, 0, pool);
+        get_addr(old_address, old_sock_addr);
+        get_addr(new_address, new_sock_addr);
+        ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s,
+                "proxy: ip of connection is %pI, the current resolved ip is %pI",
+                old_sock_addr, new_sock_addr);
+        if (strcmp(old_address, new_address)) {
+            ap_log_error(APLOG_MARK, APLOG_INFO, 0, s,
+                    "proxy: Invalidating the connection due to change in dns resolved address.");
+            /*
+             * If the address has changed, store the changed
+             * address in all relevant places and mark the
+             * connection as due to be closed.
+             */
+            conn->worker->cp->addr = new_sock_addr;
+            conn->addr = new_sock_addr;
+            conn->connection->remote_addr = new_sock_addr;
+            conn->close = 1;
+        }
+    }
+
+    connection_cleanup(conn, s);
 
     return OK;
 }
 
+static char *get_addr(char *p, apr_sockaddr_t *sa)
+{
+    apr_size_t sub_len;
+
+    if (apr_sockaddr_ip_getbuf(p, sa->addr_str_len, sa)) {
+        /* Should only fail if the buffer is too small, which it
+         * should not be; but fail safe anyway: */
+        strcpy(p, "?");
+    }
+
+    return (p);
+}
+
 PROXY_DECLARE(int)
 ap_proxy_determine_connection(apr_pool_t *p, request_rec *r,
                               proxy_server_conf *conf,