From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Shashikant Mundlik" Date: Mon, 17 Apr 2006 15:52:42 +0000 Subject: RE: [LARTC] Problems in Dead Gateway Detection / Failover Message-Id: <4443b700.67aae59b.0211.45dc@mx.gmail.com> MIME-Version: 1 Content-Type: multipart/mixed; boundary="===============1696978345==" List-Id: References: <43D8CEAE.3010006@tuxspace.com> In-Reply-To: <43D8CEAE.3010006@tuxspace.com> To: lartc@vger.kernel.org This is a multi-part message in MIME format. --===============1696978345== Content-Type: multipart/alternative; boundary="----=_NextPart_000_002D_01C66263.658F1CC0" This is a multi-part message in MIME format. ------=_NextPart_000_002D_01C66263.658F1CC0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Thanks a lot Ren! That will be a great help. Thanks, Shashikant Mundlik _____ From: Alessandro Ren [mailto:alessandro.ren@opservices.com.br] Sent: Monday, April 17, 2006 8:47 PM To: smundlik@ubicsindia.com Cc: manish@tuxspace.com; lartc@mailman.ds9a.nl Subject: Re: [LARTC] Problems in Dead Gateway Detection / Failover - MultipleISP Links I bind to the interface IP and connect to 20 different sites or more, the sites are listed in a text file, using the TCP connect in perl. Off course, the ip rule tables the the marks in the firewall must be set correcly so you know that the connections are going through the right interface. I can share de script, it's a litle complex in its structus, as it depends on some external scripts, but I will try the share and problably get more and better ideas to do the fail over / multi path routing. I will prepare and sent a email with it shortly. []s. Shashikant Mundlik wrote: Hi Ren, Thanks for your help. But how do you check that you reach less than 20 of your sites. (do you mean 20 websites?). Will you able to share the script? That will be great help. Thanks and regards, Shashikant Mundlik System Administrator UBICS, Pune Phone: 91 20 2729 1004 x 138 Mobile : 91 9372 044015 www.ubics.com The UB Group DISCLAIMER AND PRIVILEGE NOTICE: This e-mail message contains confidential, copyright, proprietary and legally privileged information. It should not be used by anyone who is not the original intended recipient. If you have erroneously received this message, please delete it immediately and notify the sender. The recipient must note and understand that any views expressed in this message are those of the individual sender and no binding nature of the message shall be implied or assumed unless the sender does so expressly with due authority of UBICS, Inc. _____ From: Alessandro Ren [mailto:alessandro.ren@opservices.com.br] Sent: Monday, April 17, 2006 7:31 PM To: smundlik@ubicsindia.com Cc: manish@tuxspace.com; lartc@mailman.ds9a.nl Subject: Re: [LARTC] Problems in Dead Gateway Detection / Failover - MultipleISP Links I have a script that connects to 20 diferent sites on the port 80 coming from each link interface a have on my linux router. If I reach less than 20% of my sites, I assume the link is down and do all the routing and firewall adjustments to make the traffic goes to other routes, removing the problematic link out, setting ip rules, routes in tables and the main multipath default route and commenting in the firewall the MARKs the would go via the link thats down and it also sets QoS and tries to bring the link that is down back UP. Althought I've tested with only 3 links, it supports any number of them. It's works very nice so far. []s. Shashikant Mundlik wrote: Hi There, I am also trying to do the same for my network. I have two links from different ISPs and I want to configure a failover and load balancing Linux router. I am facing same problem here, that how to detect link failure and let Linux box switch the gateway. I know it works when the first gateway is physically down and not reachable. But what to do if my link is up but there is problem at nexthop level and its not routing packets to destination. Please tell me if this can be overcome by setting multipath routing. Another way I can think of doing this is to use a script which will check if the default route is alive every 15 mins and if not it will make changes in routing table and route the packets through different link. I don't know if this is the best way to do this. If any one know how to do this better please share. If you guys thinks this can work, lets help each other to write such scrip. I am new to LARTC and just now started learning it to solve my network problems. Please help me to achieve this. Thanks in advance. Regards, Shashikant Mundlik Pune, India. _____ _______________________________________________ LARTC mailing list LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc -- __________________________________________________ Alessandro Ren OpServices Luciana de Abreu, 471 - Sala 403 Porto Alegre, RS - CEP 90570-060 * phone 55(51)3061-3588 * fax 55(51)3061-3588 * mobile 55(51)8151-8212 * email alessandro.ren@opservices.com.br __________________________________________________ -- __________________________________________________ Alessandro Ren OpServices Luciana de Abreu, 471 - Sala 403 Porto Alegre, RS - CEP 90570-060 * phone 55(51)3061-3588 * fax 55(51)3061-3588 * mobile 55(51)8151-8212 * email alessandro.ren@opservices.com.br __________________________________________________ ------=_NextPart_000_002D_01C66263.658F1CC0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable
Thanks a lot Ren!
That will be a great help. =
 
Thanks,
 

Shashikant Mundlik

 

From: Alessandro Ren=20 [mailto:alessandro.ren@opservices.com.br]
Sent: Monday, April = 17,=20 2006 8:47 PM
To: smundlik@ubicsindia.com
Cc:=20 manish@tuxspace.com; lartc@mailman.ds9a.nl
Subject: Re: = [LARTC]=20 Problems in Dead Gateway Detection / Failover - MultipleISP=20 Links


    I bind to the interface IP and connect = to 20=20 different sites or more, the sites are listed in a text file, using the = TCP=20 connect in perl.
    Off course, the ip rule tables = the the=20 marks in the firewall must be set correcly so you know that the = connections are=20 going through the right interface.
    I can share de = script,=20 it's a litle complex in its structus, as it depends on some external = scripts,=20 but I will try the share and problably get more and better ideas to do = the fail=20 over / multi path routing.
    I will prepare and sent = a email=20 with it shortly.

    []s.

Shashikant = Mundlik wrote:=20
Hi Ren,
 
Thanks for your help. But how do you check = that you=20 reach less than 20 of your sites. (do you mean 20=20 websites?).
Will you able to share the script?=20
That will be great help. =
 
Thanks and regards,
 

Shashikant Mundlik

System=20 Administrator

UBICS, = Pune        = ;            =             &= nbsp;       
Phone:  91 20=20 2729 1004  x = 138  
Mobile= : 91 9372=20 044015

www.ubics.com

The UB=20 Group

DISCLAIMER=20 AND PRIVILEGE NOTICE:
This e-mail = message contains=20 confidential, copyright, proprietary and legally privileged = information. It=20 should not be used by anyone who is not the original intended = recipient. If=20 you have erroneously received this message, please delete it = immediately and=20 notify the sender. The recipient must note and understand that any = views=20 expressed in this message are those of the individual sender and no = binding=20 nature of the message shall be implied or assumed unless the sender = does so=20 expressly with due authority of UBICS, Inc.

 

From: Alessandro Ren [mailto:alessandro.ren@op= services.com.br]=20
Sent: Monday, April 17, 2006 7:31 PM
To: smundlik@ubicsindia.com
Cc:=20 manish@tuxspace.com; lartc@mailman.ds9a.nl
Sub= ject:=20 Re: [LARTC] Problems in Dead Gateway Detection / Failover - = MultipleISP=20 Links


    I have a script that = connects=20 to 20 diferent sites on the port 80 coming from each link interface a = have on=20 my linux router.
    If I reach less than 20% of my = sites, I=20 assume the link is down and do all the routing and firewall = adjustments to=20 make the traffic goes to other routes, removing the problematic link = out,=20 setting ip rules, routes in tables and the main multipath default = route and=20 commenting in the firewall the MARKs the would go via the link thats = down and=20 it also sets QoS and tries to bring the link that is down back=20 UP.
    Althought I've tested with only 3 links, it = supports=20 any number of them.
    It's works very nice so=20 far.

    []s.


Shashikant Mundlik = wrote:=20
Hi = There,
 
I = am also trying=20 to do the same for my network.
I have two links from different = ISPs and=20 I want to configure a failover and load balancing Linux=20 router.
 
I = am facing same=20 problem here, that how to detect link failure and let Linux box = switch the=20 gateway.
 
I = know it works=20 when the first gateway is physically down and not reachable. But = what to do=20 if my link is up but there is problem at nexthop level and its = not=20 routing packets to destination.
 
Please tell me=20 if this can be overcome by setting multipath routing. =
 
Another way I=20 can think of doing this is to use a script which will check if the = default=20 route is alive every 15 mins and if not it will make changes in = routing=20 table and route the packets through different = link.
 
I = don't know if=20 this is the best way to do this. If any one know how to do this = better=20 please share.
 
If = you guys=20 thinks this can work, lets help each other to write such=20 scrip.
 
I = am new to=20 LARTC and just now started learning it to solve my network=20 problems.
 
Please help me=20 to achieve this.
 
Thanks in=20 advance.
 
Regards,
 

Shashikant=20 Mundlik

Pune, = India.


_______________________________________________
LARTC mailing list
LARTC@mailman.ds9a.nl
http://mai=
lman.ds9a.nl/cgi-bin/mailman/listinfo/lartc

--
__________________________________________________=
Alessandro Ren
 OpServices
Luciana de Abreu, 471 - Sala&nbs= p;403
Porto Alegre, RS - CEP 90570-060=
(   phone 55(51)3061-3588
4    fax 55(51)3061-3588
Q   mobile 55(51)8151-8212
:   email alessandro.ren@ops= ervices.com.br
__________________________________________________=

--
__________________________________________________=
Alessandro Ren
 OpServices
Luciana de Abreu, 471 - Sala&nbs= p;403
Porto Alegre, RS - CEP 90570-060=
(   phone 55(51)3061-3588
4    fax 55(51)3061-3588
Q   mobile 55(51)8151-8212
:   email alessandro.ren@ops= ervices.com.br
__________________________________________________=
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