* AS-Stats modifications for public release

2025-02-20 11:44:12 +08:00 · 2008-02-19 15:43:28 +00:00 · 2008-02-19 15:43:28 +00:00 · f0daa95e46
commit f0daa95e46
parent 9b65e833bd
15 changed files with 39398 additions and 72 deletions
--- a/145
+++ b/145
@ -0,0 +1,145 @@
+AS-Stats v1 (2008-02-19)
+a simple tool to generate per-AS traffic graphs from NetFlow records
+by Manuel Kasper, Monzoon Networks AG <mkasper@monzoon.net>
+--------------------------------------------------------------------
+
+How it works
+------------
+
+A Perl script (netflow-asstatd.pl) collects NetFlow v8 AS aggregation records
+from one or more routers. It caches them for about a minute (to prevent
+excessive writes to RRD files), identifies the link that each record refers
+to (by means of the SNMP in/out interface index), maps it to a corresponding
+"known link" and RRD data source, and then runs RRDtool. To avoid losing
+new NetFlow records while the RRD files are updated, the update task is
+run in a separate process.
+
+For each AS, a separate RRD file is created as needed. It contains two data
+sources for each link - one for inbound and one for outbound traffic.
+In generated per-AS traffic graphs, inbound traffic is shown as positive,
+while outbound traffic is shown as negative values.
+
+Another Perl script, rrd-extractstats.pl, is meant to run about once per hour.
+It sums up per-AS and link traffic during the last 24 hours, sorts the ASes
+by total traffic (descending) and writes the results to a text file. This
+is then used to display the "top N AS" and other stats by the provided PHP
+scripts.
+
+
+Prerequisites
+-------------
+
+- Perl 5.8
+- RRDtool 1.2 (with Perl "RRDs" library)
+- web server with PHP 5
+- one or more routers than can generate NetFlow v8 AS aggregation records
+
+
+Installation
+------------
+
+- Copy the perl scripts netflow-asstatd.pl and rrd-extractstats.pl to the
+  machine that will collect NetFlow records
+
+- Create a "known links" file with the following information about each
+  link that you want to appear in your AS stats:
+  	
+  	- IP address of router (= source IP of NetFlow datagrams)
+  	- SNMP interface index of interface (use "show snmp mib ifmib ifindex"
+  	  to find out)
+  	- a short "tag" (15 chars max., alphanumerics only) that will be used
+  	  internally (e.g. for RRD DS names)
+  	- a human-readable description (will appear in the generated graphs)
+  	- a color code for the graphs (HTML style, 6 hex digits)
+  
+  See the example file provided (netflow-knownlinks) for the format.
+
+- Create a directory to hold per-AS RRD files. For each AS, about 128 KB of
+  storage are required, and there could be (in theory) up to 64511 ASes.
+
+- Start netflow-asstatd.pl in the background (or, better yet, write a
+  startup script for your operating system to automatically start
+  netflow-asstatd.pl on boot):
+  
+  	nohup netflow-asstatd.pl /path/to/rrd/dir /path/to/knownlinks &
+
+  By default, netflow-asstatd.pl will listen on port 9000 (UDP) for NetFlow
+  datagrams. Edit $server_port in the script if you want to change that.
+  It's a good idea to make sure only UDP datagrams from your trusted routers
+  will reach the machine running netflow-asstatd.pl (firewall etc.).
+
+- Have your router(s) send NetFlow v8 AS aggregation records to your machine.
+  This is typically done with commands like the following (Cisco IOS):
+
+		ip flow-cache timeout active 5
+		
+		! enable ip flow ingress on all interfaces listed in your
+		! "known links" file
+		int Gi0/x.y
+		  ip flow ingress
+		  
+		ip flow-export source <source interface>
+		ip flow-export version 5 origin-as
+		ip flow-aggregation cache as
+		 cache timeout active 5
+		 export destination <IP address of server running AS stats> 9000
+		 enabled  
+
+  Note that the version has to be specified as 5, even though the AS
+  aggregation records will actually be v8. Also, setting the global flow
+  cache timeout to 5 minutes is necessary to get "smooth" traffic graphs
+  (default is 30 minutes), as a flow is only counted when it expires from
+  the cache. Decreasing the flow-cache timeout may result in a slight
+  increase in CPU usage (and NetFlow AS aggregation takes its fair share of
+  CPU as well, of course).
+
+- Wait 1-2 minutes. You should then see new RRD files popping up in the
+  directory that you defined/created earlier on. If not, make sure that
+  netflow-asstatd.pl is running, not spewing out any error messages, and that
+  the NetFlow datagrams are actually reaching your machine (tcpdump...).
+
+- Add a cronjob to run the following command every hour:
+
+	rrd-extractstats.pl /path/to/rrd/dir /path/to/knownlinks \
+		/path/to/asstats_day.txt
+
+  That script will go through all RRD files and collect per-link summary
+  stats for each AS, sort them by total traffic (descending), and write them
+  to a text file. The "top N AS" page uses this to determine which ASes to show.
+  
+- Copy the contents of the "www" directory to somewhere within your web server's
+  document root and change file paths in func.inc as necessary.
+
+- Wait a few hours for data to accumulate. :)
+
+- Access the provided PHP scripts via your web server and marvel at the
+  (hopefully) beautiful graphs.
+
+
+Adding a new link
+-----------------
+Adding a new link involves adding two new data sources to all RRD files.
+This is a bit of a PITA since RRDtool itself doesn't provide a command to do
+that. A simple (but slow) Perl script that is meant to be used with RRDtool's
+XML dump/restore feature is provided (add_ds_proc.pl, add_ds.sh). Note that
+netflow-asstatd.pl should be stopped while modifying RRD files, to avoid
+breaking them with concurrent modifications.
+
+
+Changing the RRAs
+-----------------
+By default, the created RRDs keep data as follows:
+
+	* 48 hours at 5 minute resolution
+	* 1 week at 1 hour resolution
+	* 1 year at 1 day resolution
+
+If you want to change that, modify the getrrdfile() function in
+netflow-asstatd.pl and delete any old RRD files.
+
+
+To do
+-----
+
+- rrd-extractstats.pl uses a lot of memory and could probably use some
+  optimization.
--- a/bin/netflow-asstatd.pl
+++ b/bin/netflow-asstatd.pl
@ -2,29 +2,29 @@
 #
 # $Id$
 #
-# (c) 2008 Monzoon Networks AG. All rights reserved.
+# written by Manuel Kasper, Monzoon Networks AG <mkasper@monzoon.net>

 use strict;
 use IO::Socket;
 use RRDs;

-my %knownlinks = (
-	# key format is "<router IP>_<SNMP ifindex>"
-	# max. alias length is 16 characters; only [a-zA-Z0-9] allowed
-	'80.254.79.250_44' => 'tix',
-	'80.254.79.250_45' => 'sunrise',
-	'80.254.79.250_47' => 'swissixzrh',
-	'80.254.79.250_65' => 'dtag',
-	'80.254.79.251_7' => 'colt',
-	'80.254.79.251_8' => 'swissixglb'
-);
+if ($#ARGV != 1) {
+	die("Usage: $0 <path to RRD file directory> <path to known links file>\n");
+}
+
+my $rrdpath = $ARGV[0];
+my $knownlinksfile = $ARGV[1];
+
+if (! -d $rrdpath) {
+	die("$rrdpath does not exist or is not a directory\n");
+}
+
+my %knownlinks;

 my $ascache = {};
 my $ascache_lastflush = 0;
 my $ascache_flush_interval = 60;

-my $rrdpath = "/var/db/netflow/rrd";
-
 my $server_port = 9000;
 my $MAXREAD = 8192;
 my $header_len = 28;
@ -47,6 +47,9 @@ sub TERM {
 	exit 0;
 }

+# read known links file
+read_knownlinks();
+
 # prepare to listen for NetFlow UDP packets
 my $server = IO::Socket::INET->new(LocalPort => $server_port, Proto => "udp")
 	  or die "Couldn't be a udp server on port $server_port : $@\n";
@ -195,9 +198,9 @@ sub getrrdfile {
 			push(@args, "DS:${alias}_in:ABSOLUTE:300:U:U");
 			push(@args, "DS:${alias}_out:ABSOLUTE:300:U:U");
 		}
-		push(@args, "RRA:AVERAGE:0:1:576");		# 48 hours at 5 minute resolution
-		push(@args, "RRA:AVERAGE:0:12:168");	# 1 week at 1 hour resolution
-		push(@args, "RRA:AVERAGE:0:288:366");	# 1 year at 1 day resolution
+		push(@args, "RRA:AVERAGE:0.99999:1:576");	# 48 hours at 5 minute resolution
+		push(@args, "RRA:AVERAGE:0.99999:12:168");	# 1 week at 1 hour resolution
+		push(@args, "RRA:AVERAGE:0.99999:288:366");	# 1 year at 1 day resolution
 		RRDs::create($rrdfile, "--start", $startts, @args);
 		
 		my $ERR = RRDs::error;
@ -209,3 +212,15 @@ sub getrrdfile {
 	
 	return $rrdfile;
 }
+
+sub read_knownlinks {
+	open(KLFILE, $knownlinksfile) or die("Cannot open $knownlinksfile!");
+	while (<KLFILE>) {
+		chomp;
+		next if (/(^\s*#)|(^\s*$)/);	# empty line or comment
+		
+		my ($routerip,$ifindex,$tag,$descr,$color) = split(/\t+/);
+		$knownlinks{"${routerip}_${ifindex}"} = $tag;
+	}
+	close(KLFILE);
+}
--- a/bin/rrd-extractstats.pl
+++ b/bin/rrd-extractstats.pl
@ -2,28 +2,24 @@
 #
 # $Id$
 #
-# (c) 2008 Monzoon Networks AG. All rights reserved.
+# written by Manuel Kasper, Monzoon Networks AG <mkasper@monzoon.net>

+use strict;
 use RRDs;

-if ($#ARGV != 0) {
-	die("Usage: $0 outfile\n");
+if ($#ARGV != 2) {
+	die("Usage: $0 <path to RRD file directory> <path to known links file> outfile\n");
 }

-my %knownlinks = (
-	# key format is "<router IP>_<SNMP ifindex>"
-	# max. alias length is 16 characters; only [a-zA-Z0-9] allowed
-	'80.254.79.250_44' => 'tix',
-	'80.254.79.250_45' => 'sunrise',
-	'80.254.79.250_47' => 'swissixzrh',
-	'80.254.79.250_65' => 'dtag',
-	'80.254.79.251_7' => 'colt',
-	'80.254.79.251_8' => 'swissixglb'
-);
-my @links = values %knownlinks;
+my $rrdpath = $ARGV[0];
+my $knownlinksfile = $ARGV[1];
+my $statsfile = $ARGV[2];

-my $rrdpath = "/var/db/netflow/rrd";
-my $statsfile = $ARGV[0];
+my %knownlinks;
+
+read_knownlinks();
+
+my @links = values %knownlinks;

 # walk through all RRD files in the given path and extract stats for all links
 # from them; write the stats to a text file, sorted by total traffic
@ -63,7 +59,7 @@ my @asorder = sort {
 	return $total_b <=> $total_a;
 } keys %$astraffic;

-open(STATSFILE, ">$statsfile");
+open(STATSFILE, ">$statsfile.tmp");

 # print header line
 print STATSFILE "as";
@ -86,6 +82,8 @@ foreach my $as (@asorder) {

 close(STATSFILE);

+rename("$statsfile.tmp", $statsfile);
+
 sub gettraffic {

 	my $as = shift;
@ -132,3 +130,15 @@ sub gettraffic {
 	
 	return $retdata;
 }
+
+sub read_knownlinks {
+	open(KLFILE, $knownlinksfile) or die("Cannot open $knownlinksfile!");
+	while (<KLFILE>) {
+		chomp;
+		next if (/(^\s*#)|(^\s*$)/);	# empty line or comment
+		
+		my ($routerip,$ifindex,$tag,$descr,$color) = split(/\t+/);
+		$knownlinks{"${routerip}_${ifindex}"} = $tag;
+	}
+	close(KLFILE);
+}
--- a/conf/netflow-knownlinks
+++ b/conf/netflow-knownlinks
@ -1,8 +1,9 @@
 # Router IP		SNMP ifindex	tag				description		color
 # note: tabs must be used to separate fields (not spaces)
-80.254.79.250	45				sunrise			Sunrise			D41C0E
-80.254.79.250	65				dtag			DTAG			E45605
-80.254.79.251	7				colt			Colt			FECF12
-80.254.79.250	44				tix				TIX				0A4484
-80.254.79.250	47				swissixzrh		SwissIX zrh		0A7484
-80.254.79.251	8				swissixglb		SwissIX glb		4CB4C4
+192.0.2.1		15				uplink1			Uplink 1		D41C0E
+192.0.2.1		23				uplink2			Uplink 2		E45605
+192.0.2.2		4				uplink3			Uplink 3		FECF12
+192.0.2.3		11				uplink4			Uplink 4		5EA631
+192.0.2.2		42				peering1		IXP 1			0A4484
+192.0.2.2		45				peering2		IXP 2			0A7484
+192.0.2.3		6				peering3		IXP 3			4CB4C4
--- a/tools/add_ds.sh
+++ b/tools/add_ds.sh
@ -0,0 +1,8 @@
+#!/bin/sh
+
+for f in *.rrd; do
+	echo "file: $f"
+	mv $f $f.old
+	rrdtool dump $f.old | /path/to/add_ds_proc.pl | rrdtool restore - $f.new
+	mv $f.new $f
+done
--- a/tools/add_ds_proc.pl
+++ b/tools/add_ds_proc.pl
@ -0,0 +1,82 @@
+#!/usr/bin/perl
+
+use strict;
+
+my $ds = 2;
+
+# change the name(s) of the new data sources here
+my @dsnames = ('newlink_in', 'newlink_out');
+
+my $default_val = 'NaN';
+my $type = 'ABSOLUTE';
+my $heartbeat = '300';
+my $rrdmin = 'NaN';
+my $rrdmax = 'NaN';
+
+my $cdp_prep_end = '</cdp_prep>';
+
+my $row_end = '</row>';
+my $name = '<name>';
+my $name_end = '</name>';
+
+my $field = '<v> ' . $default_val . ' </v>';
+
+my $found_ds = 0;
+my $num_sources = 0;
+my $last;
+my $fields = " ";
+my $datasource;
+my $x;
+
+while (<STDIN>) {
+
+  if (($_ =~ s/$row_end$/$fields$row_end/) && $found_ds) {
+    # need to hit <ds> types first, if we don't, we're screwed
+    print $_; 
+
+  } elsif (/$cdp_prep_end/) {
+    for (my $j = 0; $j < $ds; $j++) {
+      print "\t\t\t<ds>\n" . 
+            "\t\t\t<primary_value> 0.0000000000e+00 </primary_value>\n" .
+            "\t\t\t<secondary_value> 0.0000000000e+00 </secondary_value>\n" .
+            "\t\t\t<value> NaN </value>\n" .
+            "\t\t\t<unknown_datapoints> 0 </unknown_datapoints>\n" .
+            "\t\t\t</ds>\n";
+    }
+    print $_;
+
+  } elsif (/$name_end$/) {
+    ($datasource) = /$name (\w+)/;
+    $found_ds++;
+    print $_;
+
+  } elsif (/Round Robin Archives/) {
+    # print out additional datasource definitions
+
+    ($num_sources) = ($datasource =~ /(\d+)/);
+    
+    for ($x = $num_sources+1; $x < $num_sources+$ds+1; $x++) {
+
+      $fields .= $field;
+      
+      print "\n\t<ds>\n";
+      print "\t\t<name> " . $dsnames[$x-1] . " <\/name>\n";
+      print "\t\t<type> $type <\/type>\n";
+      print "\t\t<minimal_heartbeat> $heartbeat <\/minimal_heartbeat>\n";
+      print "\t\t<min> $rrdmin <\/min>\n";
+      print "\t\t<max> $rrdmax <\/max>\n\n";
+      print "\t\t<!-- PDP Status-->\n";
+      print "\t\t<last_ds> U <\/last_ds>\n";
+      print "\t\t<value> NaN <\/value>\n";
+      print "\t\t<unknown_sec> 0 <\/unknown_sec>\n"; 
+      print "\t<\/ds>\n\n";
+
+    }
+
+    print $_;
+  } else {
+    print $_;
+  }
+
+  $last = $_;
+}
--- a/www/asinfo.txt
+++ b/www/asinfo.txt
--- a/www/func.inc
+++ b/www/func.inc
@ -2,28 +2,62 @@
 /*
 * $Id$
 * 
- * (c) 2008 Monzoon Networks AG. All rights reserved.
+ * written by Manuel Kasper, Monzoon Networks AG <mkasper@monzoon.net>
 */

-$dbpath = "/var/db/netflow";
-$rrdpath = "$dbpath/rrd";
+$rrdpath = "/var/db/netflow/rrd";
+$daystatsfile = "/var/db/netflow/asstats_day.txt";
 $rrdtool = "/usr/local/bin/rrdtool";

-$knownlinksfile = "/monzoon/conf/netflow-knownlinks";
-$topasdayfile = "$dbpath/top50_day.txt";
-
-$link = mysql_connect("localhost", "netflow", "ycCeDm71ck");
-mysql_select_db("netflow", $link);
+$asinfofile = "asinfo.txt";
+$knownlinksfile = "/etc/netflow-knownlinks";

+/* note: you might want to put the data from asinfo.txt into an SQL
+   database to avoid having to read the whole file all the time */
 function getASInfo($asnum) {
-	$row = mysql_fetch_array(mysql_query("select * from asnums where asn='" . addslashes($asnum) . "'"));
+	global $asinfodb;
+	
+	if (!isset($asinfodb))
+		$asinfodb = readasinfodb();
+	
+	if ($asinfodb[$asnum])
+		return $asinfodb[$asnum];
+	else
+		return array(name => "AS$asnum", descr => "AS $asnum");
+	
+	/*$row = mysql_fetch_array(mysql_query("select * from asnums where asn='" . addslashes($asnum) . "'"));
 	
 	if ($row) {
 		return array(name => $row['asname'], descr => $row['descr'], country => $row['country']);
 	} else {
-		/* not found */
 		return array(name => "AS$asnum", descr => "AS $asnum");
+	}*/
+}
+
+function readasinfodb() {
+	global $asinfofile;
+	
+	if (!file_exists($asinfofile))
+		return array();
+	
+	$fd = fopen($asinfofile, "r");
+	$asinfodb = array();
+	while (!feof($fd)) {
+		$line = trim(fgets($fd));
+		if (preg_match("/(^\\s*#)|(^\\s*$)/", $line))
+			continue;	/* empty line or comment */
+		
+		list($asn,$asname,$descr,$country) = explode("\t", $line);
+		
+		$asinfodb[$asn] = array(
+			name => $asname,
+			descr => $descr,
+			country => $country
+		);
 	}
+	fclose($fd);
+	
+	return $asinfodb;
 }

 function getknownlinks() {
@ -52,10 +86,10 @@ function getknownlinks() {
 }

 function getasstats_top($ntop) {
-	global $dbpath;
+	global $daystatsfile;
 	
 	/* first step: walk the data for all ASes to determine the top 5 for the given link */
-	$fd = fopen("$dbpath/asstats_day.txt", "r");
+	$fd = fopen($daystatsfile, "r");
 	if (!$fd)
 		return array();
 	$cols = explode("\t", trim(fgets($fd)));
@ -74,7 +108,7 @@ function getasstats_top($ntop) {
 		$tot_out = 0;
 		
 		for ($i = 1; $i < count($els); $i++) {
-			if (strpos($cols[$i], "in") !== false)
+			if (strpos($cols[$i], "_in") !== false)
 				$tot_in += $els[$i];
 			else
 				$tot_out += $els[$i];
@ -101,5 +135,4 @@ function format_bytes($bytes) {
 		return "$bytes bytes";
 }

-
 ?>
--- a/www/gengraph.php
+++ b/www/gengraph.php
@ -2,7 +2,7 @@
 /*
 * $Id$
 * 
- * (c) 2008 Monzoon Networks AG. All rights reserved.
+ * written by Manuel Kasper, Monzoon Networks AG <mkasper@monzoon.net>
 */

 require_once('func.inc');
--- a/www/history.php
+++ b/www/history.php
@ -2,7 +2,7 @@
 /*
 * $Id$
 * 
- * (c) 2008 Monzoon Networks AG. All rights reserved.
+ * written by Manuel Kasper, Monzoon Networks AG <mkasper@monzoon.net>
 */

 require_once('func.inc');
@ -12,10 +12,12 @@ if ($as)
 	$asinfo = getASInfo($as);

 ?>
-<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
+        "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
 <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
 <head>
 	<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
+	<meta http-equiv="Refresh" content="300" />
 	<title>History for AS<?php echo $as; ?>: <?php echo $asinfo['descr']; ?></title>
 	<link rel="stylesheet" type="text/css" href="style.css" />
 </head>
@ -28,7 +30,7 @@ if ($as)
 <div class="pgtitle">History for AS<?php echo $as; ?>: <?php echo $asinfo['descr']; ?></div>

 <?php if (!file_exists("$rrdpath/$as.rrd")): ?>
-No data found for AS <?php echo $as; ?>
+<p>No data found for AS <?php echo $as; ?></p>
 <?php else: ?>
 <div class="title">Daily</div>
 <img class="detailgraph" src="gengraph.php?as=<?php echo $as; ?>" alt="daily graph" />
@ -46,14 +48,14 @@ No data found for AS <?php echo $as; ?>

 <div class="pgtitle">View history for an AS</div>

-<form action="" method="GET">
-AS: <input type="text" name="as" size="6">
-<input type="submit" value="Go">
+<form action="" method="get">
+AS: <input type="text" name="as" size="6" />
+<input type="submit" value="Go" />
 </form>
 <?php endif; ?>

 <div id="footer">
-&copy; 2008 Monzoon Networks AG. All rights reserved.
+AS-Stats v1 written by Manuel Kasper, Monzoon Networks AG.
 </div>

 </body>
--- a/www/images/spacer.gif
+++ b/www/images/spacer.gif
--- a/www/index.php
+++ b/www/index.php
@ -2,7 +2,7 @@
 /*
 * $Id$
 * 
- * (c) 2008 Monzoon Networks AG. All rights reserved.
+ * written by Manuel Kasper, Monzoon Networks AG <mkasper@monzoon.net>
 */

 header("Location: top.php");
--- a/www/linkgraph.php
+++ b/www/linkgraph.php
@ -2,12 +2,15 @@
 /*
 * $Id$
 * 
- * (c) 2008 Monzoon Networks AG. All rights reserved.
+ * written by Manuel Kasper, Monzoon Networks AG <mkasper@monzoon.net>
 */

 require_once('func.inc');

 $numtop = 10;
+if ($_GET['numtop'] && $_GET['numtop'] <= 50)
+	$numtop = $_GET['numtop'];
+
 $ascolors = array("D41C0E", "E45605", "FECF12", "2FA11C", "19BB7C", "0A4484", "0A7484", "4CB4C4", "971928", "1f348c");

 $link = $_GET['link'];
@ -15,7 +18,7 @@ if (!preg_match("/^[a-z0-9]+$/", $link))
 	die("Invalid link");

 /* first step: walk the data for all ASes to determine the top 5 for the given link */
-$fd = fopen("$dbpath/asstats_day.txt", "r");
+$fd = fopen($daystatsfile, "r");
 $cols = explode("\t", trim(fgets($fd)));
 $asstats = array();

--- a/www/linkusage.php
+++ b/www/linkusage.php
@ -2,7 +2,7 @@
 /*
 * $Id$
 * 
- * (c) 2008 Monzoon Networks AG. All rights reserved.
+ * written by Manuel Kasper, Monzoon Networks AG <mkasper@monzoon.net>
 */

 require_once('func.inc');
@ -10,10 +10,12 @@ require_once('func.inc');
 $knownlinks = getknownlinks();

 ?>
-<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
+        "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
 <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
 <head>
 	<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
+	<meta http-equiv="Refresh" content="300" />
 	<title>Link usage</title>
 	<link rel="stylesheet" type="text/css" href="style.css" />
 </head>
@ -35,7 +37,7 @@ $class = (($i % 2) == 0) ? "even" : "odd";
 		</div>
 	</th>
 	<td>
-		<img src="linkgraph.php?link=<?php echo $link['tag']; ?>&width=500&height=300" width="581" height="494" border="0">
+		<img alt="link graph" src="linkgraph.php?link=<?php echo $link['tag']; ?>&width=500&height=300" width="581" height="494" border="0" />
 	</td>
 </tr>
 <?php $i++; endforeach; ?>
@ -43,7 +45,7 @@ $class = (($i % 2) == 0) ? "even" : "odd";
 </table>

 <div id="footer">
-&copy; 2008 Monzoon Networks AG. All rights reserved.
+AS-Stats v1 written by Manuel Kasper, Monzoon Networks AG.
 </div>

 </body>
--- a/www/top.php
+++ b/www/top.php
@ -17,10 +17,12 @@ if ($ntop > 200)
 $topas = getasstats_top($ntop);

 ?>
-<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
+        "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
 <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
 <head>
 	<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
+	<meta http-equiv="Refresh" content="300" />
 	<title>Top <?php echo $ntop; ?> AS</title>
 	<link rel="stylesheet" type="text/css" href="style.css" />
 </head>
@ -28,7 +30,7 @@ $topas = getasstats_top($ntop);
 <body>

 <div id="nav">
-<form action="" method="GET">
+<form action="" method="get">
 Number of AS: 
 <input type="text" name="n" size="4" value="<?php echo $ntop; ?>" />
 <input type="submit" value="Go" style="margin-right: 2em" />
@ -62,7 +64,7 @@ $class = (($i % 2) == 0) ? "even" : "odd";
 		</div>
 	</th>
 	<td>
-		<a href="history.php?as=<?php echo $as; ?>" target="_blank"><img src="gengraph.php?as=<?php echo $as; ?>&width=500&height=150&nolegend=1" width="581" height="204" border="0"></a>
+		<a href="history.php?as=<?php echo $as; ?>" target="_blank"><img alt="AS graph" src="gengraph.php?as=<?php echo $as; ?>&width=500&height=150&nolegend=1" width="581" height="204" border="0" /></a>
 	</td>
 </tr>
 <?php $i++; endforeach; ?>
@ -88,7 +90,7 @@ foreach ($knownlinks as $link) {
 </div>

 <div id="footer">
-&copy; 2008 Monzoon Networks AG. All rights reserved.
+AS-Stats v1 written by Manuel Kasper, Monzoon Networks AG.
 </div>

 </body>