From mboxrd@z Thu Jan 1 00:00:00 1970 From: Esteban Ribicic Date: Mon, 03 Mar 2003 15:55:18 +0000 Subject: Re: [LARTC] further than dead gateway detection MIME-Version: 1 Content-Type: multipart/mixed; boundary="=-dTj+pwNuZGF+N5iSjsOY" Message-Id: List-Id: References: In-Reply-To: To: lartc@vger.kernel.org --=-dTj+pwNuZGF+N5iSjsOY Content-Type: text/plain; charset=koi8-r Content-Transfer-Encoding: quoted-printable when interface goes down you must flush the cache to generate a new routing table. this perl script cheks and fix this. have you done masquerading from an internal network?=20 cause that does not work for mi..you may help me :) On Mon, 2003-03-03 at 10:43, =EE=C9=CB=C9=D4=C1 =F7=C9=CE=CF=CB=D5=D2=CF=D7= wrote: > Hi all! >=20 > I have a set up of router with two ISP providers. Each on ADSL modem and= with public IP address. I've the patch from Julian Anastasov applied (rout= ed-2.4.20-9.diff). > External interfaces are: eth1 and eth2, internal is: eth0. The modems ser= ve as gateways to my router, so, I simply set them as gateways on correspon= dent interfaces. >=20 > Multipath routing is implemented as two nexthop's: >=20 > ip route add default table 222 proto static \ > nexthop via $GATEWAY1 dev eth1 weight 1 \ > nexthop via $GATEWAY2 dev eth2 weight 10 >=20 > so when I plug-off the eth1 link to first modem, all the traffic moves to= go through the eth2 and vice-versa. It works successfully. >=20 > The problem is that the most probably situation is not when one of my gat= eways is down (because it's really a modem and I have full access to it), b= ut when the modem link to one of providers is down. So almost always I have= the routes to be present in the system (I think because of the gateways ar= e really up) and cached while one of my provider is down. The point is that= the packets passed through the eth2 keep the same route even after my seco= nd provider fails (but gateway remains reachable) and they dont want to swi= tch to the eth1. So any connection seems not working. >=20 > Please, help. How to detect that the link _behind_ a gateway is break? Al= l the time gateways are reachable. _______________________ >=20 > -- > Nikita________________ > _______________________________________________ > LARTC mailing list / LARTC@mailman.ds9a.nl > http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/ >=20 --=20 Esteban Ribicic Network Operation Center UOL-Sinectis S.A. Florida 537 Piso 6, Buenos Aires, Argentina=20 +54-11-4321-9110 Ext 2503 +54-11-4321-9107 Directo=20 eribicic@uolsinectis.com www.uolsinectis.com --=-dTj+pwNuZGF+N5iSjsOY Content-Disposition: attachment; filename=ClearRoutingCache.pl Content-Transfer-Encoding: quoted-printable Content-Type: text/x-perl; name=ClearRoutingCache.pl; charset=ANSI_X3.4-1968 #!/usr/bin/perl # # Limpia el routing cache de ser necesario # $PATH_IP=3D"/bin/ip"; my @routels=3D`$PATH_IP route ls`; for (@routels) { chop($_); if ( $_=3D~/dead/ ) { system("$PATH_IP route flush cache"); print "done\n"; } } --=-dTj+pwNuZGF+N5iSjsOY-- _______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/