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Mark Hagger

2002-Jan-22 11:31 UTC

help with config for multiple internet connections

Hi,

I have a machine with 2 internet connections (one is effectively the
backup one).

I''m having some trouble getting this to work.  What I want is to have
one
connection as the default gateway, and the other to also be live for
incoming connections.  The theory is that if the "first" connection
dies
then the "second" would work (one of the links is ADSL, hence the
unreliability....).

I''m using a Mandrake8.1 installation, with a recent kernel.  If I setup
the network cards in the "usual way" I get a "route table"
of the
following:

10.252.0.64   0.0.0.0     255.255.255.240 U  0  0 0 eth0
62.188.57.139 0.0.0.0     255.255.255.248 U  0  0 0 eth1
127.0.0.0     0.0.0.0     255.0.0.0       U  0  0 0 lo
0.0.0.0      10.252.0.65    0.0.0.0       UG 0  0 0 eth0

unfortunately this doesn''t work at all, connections to the external
address that maps to 10.252.0.64 work fine, but incoming traffic to
62.188.57.139 apparently goes nowhere, probably not surprising as return
traffic out of 62.188.57.139 should go via a gateway of .142.  If I switch
the default gateway to the .142 address then the eth1 network works and
the eth0 doesn''t.

I''m somewhat baffled as to what I''m supposed to do to have
this working,
all help and suggestions gratefully received.

Regards,

Mark Hagger

Julian Anastasov

2002-Jan-22 23:42 UTC

head link

Re: help with config for multiple internet connections

Hello,

On Tue, 22 Jan 2002, Mark Hagger wrote:
> I have a machine with 2 internet connections (one is effectively the
> backup one).
> I''m somewhat baffled as to what I''m supposed to do to
have this working,
> all help and suggestions gratefully received.
	You can start with some docs:

http://www.linuxvirtualserver.org/~julian/#routes
nano.txt, dgd-usage.txt, dgd.txt
> Regards,
>
> Mark Hagger
Regards

--
Julian Anastasov <ja@ssi.bg>

Whit Blauvelt

2002-Feb-07 03:43 UTC

head link

Perl script to adjust default routing on 2 Net connections

Using a stock implementation of Christoph''s and Julian''s setup
for
connecting to two lines (DSL from different ISPs in my case) I ran into
situations where a gateway was still up, but the ISP had systems down beyond
it. To deal with that, I''ve put together a perl script that I run from
cron.
I have this running in production, but only for a few days, so it''s not
thoroughly tested yet. Still, I''ll include it here in case either
it''s
useful to someone, or someone has suggestions on how to improve it.

It should also be adaptable to similar setups, although if you''re not
using
Julian''s patches you should search and replace "proto static"
with nothing
first (not even sure it''s doing any good in this context anyway, but
not
sure it isn''t).

Run it from the prompt to test before adding to cron.

Whit

--- cut ---
#!/usr/local/bin/perl

# checkroutes.pl version 0.04, 6 Feb. 2002, whit@transpect.com
# Extends stock Nano-Howto setup with upstream route accessibility checking
# See http://www.linuxvirtualserver.org/~julian/nano.txt and patches at
# http://www.linuxvirtualserver.org/~julian/#routes
# (if not using Julian''s patchs, remove "proto static"
occurrences below)

# Run from cron (set with "crontab -e")
# example: "0-59/2 * * * * /path/to/checkroutes.pl" runs this every 2
minutes

# Best IPs to test may be last IPs at ISP before routing out to Net

# If perl not at /usr/local/bin/perl change first line to point to it

# Before running install Net::Ping from http://freeware.roobik.com/netping/
# (untar, cd to directory, "perl Makefile.PL; make; make install")

use Net::Ping;

# User settings
# _____________

$ip	= "/usr/sbin/ip";	# Location of "ip" on system

$gw1 	= ""; # Gateway 1 IP
$dev1	= ""; # Device (e.g., eth1)
$tip1	= ""; # Upstream IP to test
$src1	= ""; # Source address for outgoing packets
$wei1	= "1"; # Weight

$gw2	= ""; # Gateway 2 IP
$dev2	= ""; # Device (e.g., eth2)
$tip2	= ""; # Upstream IP to test
$src2	= ""; # Source address for outgoing packets
$wei2	= "1"; # Weight

$tab	= "222"; # Table to set routes in

$logfile = "/var/log/checkroutes.log"; # File to log messages to 

# create timestamp for log
# ________________________

sub TimeStamp {

	# subroutine to create a "nice" looking timestamp
	# that doesn''t rely on the system''s ''date''
command

	my @days =
(''Sun'',''Mon'',''Tue'',''Wed'',''Thu'',''Fri'',''Sat'');
	my @months =
(''Jan'',''Feb'',''Mar'',''Apr'',''May'',''Jun'',''Jul'',''Aug'',''Sep'',
		''Oct'',''Nov'',''Dec'');

	my ($sec,$min,$hour,$dom,$mon,$year,$wday,$yday,$isd) = localtime(time);
	my $timestamp = sprintf("%3s %3s %02d %4d  %02d:%02d:%02d",
$days[$wday],
		$months[$mon], $dom, $year+1900, $hour, $min, $sec);

	return $timestamp;
} 

# be sure routes are set via appropriate gateways to test IPs 
# ___________________________________________________________

$checkro = `$ip ro ls`;
if (!($checkro =~ /$tip1/)) {
	system ("$ip ro add to $tip1 via $gw1 src $src1 proto static")
		|| die ("failure adding route\n");
}
if (!($checkro =~ /$tip2/)) {
	system ("$ip ro add to $tip2 via $gw2 src $src2 proto static")
		|| die ("failure adding route\n");
}

# test if $gw1 and/or $gw2 currently in table $tab
# ________________________________________________

$checkgw = qx/$ip ro ls tab $tab/;

if ($checkgw =~ /$gw1/) {
	$check1 = 1;
} else {
	$check1 = 0;
}

if ($checkgw =~ /$gw2/) {
	$check2 = 1;
} else {
	$check2 = 0;
}

# ping the test IPs $tip1 and $tip2
# _________________________________

$p = Net::Ping->new("icmp");
if ($p->ping($tip1)) {
	$live1 = 1;
} else {
	$live1 = 0;
}
$p->close();
$p = Net::Ping->new("icmp");
if ($p->ping($tip2)) {
	$live2 = 1;
} else {
	$live2 = 0;
}
$p->close();

# If the current default in table $tab does not match the ping results then
# if only one route''s test IP is pingable change the default to that
route
# or if both test IPs are pingable change the default to use both
# or if neither test IPs are pingable change the default to use both 
# (might as well continue to try them, if we''re not going anywhere
anyway)
# _________________________________________________________________________

if (($check1 != $live1)||($check2 != $live2)) {
	if ((($live1 == 1)&&($live2 == 1))||(($live1 == 0)&&($live2 ==
0))) {
		system ("$ip ro ap default tab $tab proto static nexthop via $gw1 dev
$dev1 weight $wei1 nexthop via $gw2 dev $dev2 weight $wei2")
			|| die ("failure appending route\n");
	} elsif (($live1 == 1)&&($live2 == 0)) {
		system ("$ip ro ap default tab $tab proto static via $gw1 dev
$dev1")
			|| die ("failure appending route\n");
	} elsif (($live1 == 0)&&($live2 == 1)) {
		system ("$ip ro ap default tab $tab proto static via $gw2 dev
$dev2")
			|| die ("failure appending route\n");
	} else {
		die ("value out of bounds\n");
	}
	system ("$ip ro del default tab $tab")
		|| die ("failure deleting default route\n");
	system ("$ip ro flush cache")
		|| die ("failure flushing cache\n");
}

# log
# ___

if (($live1 == 1)&&($live2 == 1)) {
	$log = "both UP";
} elsif (($live1 == 0)&&($live2 == 0)) {
	$log = "both DOWN (set UP)";
} elsif (($live1 == 1)&&($live2 == 0)) {
	$log = "$gw1 up, $gw2 DOWN";
} elsif (($live1 == 0)&&($live2 == 1)) {
	$log = "$gw2 up, $gw1 DOWN";
}

open(LOG, ">>$logfile");
print LOG &TimeStamp . " - $log\n";
close(LOG);

Whit Blauvelt

2002-Feb-20 02:25 UTC

head link

Re: Perl script to adjust default routing on 2 Net connections

Slightly updated - the "die" error catchers didn''t always do
what I
expected, so gone for now. Otherwise this has been behaving well.

Whit

--- cut --- 

#!/usr/local/bin/perl

# checkroutes.pl version 0.05, 18 Feb. 2002, whit@transpect.com
# changed from 0.04: (1) removed disfunctional "die" statements
#                    (2) added double check that for extra "default"

# Extends stock Nano-Howto setup with upstream route accessibility checking
# See http://www.linuxvirtualserver.org/~julian/nano.txt and patches at
# http://www.linuxvirtualserver.org/~julian/#routes
# (if not using Julian''s patchs, remove "proto static"
occurrences below)

# Run from cron (set with "crontab -e")
# example: "0-59/2 * * * * /path/to/checkroutes.pl" runs this every 2
minutes

# Best IPs to test may be last IPs at ISP before routing out to Net

# If perl not at /usr/local/bin/perl change first line to point to it

# Before running install Net::Ping from http://freeware.roobik.com/netping/
# (untar, cd to directory, "perl Makefile.PL; make; make install")

use Net::Ping;

# User settings
# _____________

$ip	= "/usr/sbin/ip";	# Location of "ip" on system

$gw1 	= "";	# Gateway 1 IP
$dev1	= "";		# Device (e.g., eth1)
$tip1	= "";	# Upstream IP to test
$src1	= "";	# Source address for outgoing packets
$wei1	= "";			# Weight

$gw2	= "";	# Gateway 2 IP
$dev2	= "";		# Device (e.g., eth2)
$tip2	= "";	# Upstream IP to test
$src2	= "";	# Source address for outgoing packets
$wei2	= "";			# Weight

$tab	= "222";		# Table to set routes in

$logfile = "/var/log/checkroutes.log"; # File to log messages to 

# create timestamp for log
# ________________________

sub TimeStamp {

	# subroutine to create a "nice" looking timestamp
	# that doesn''t rely on the system''s ''date''
command

	my @days =
(''Sun'',''Mon'',''Tue'',''Wed'',''Thu'',''Fri'',''Sat'');
	my @months =
(''Jan'',''Feb'',''Mar'',''Apr'',''May'',''Jun'',''Jul'',''Aug'',''Sep'',
		''Oct'',''Nov'',''Dec'');

	my ($sec,$min,$hour,$dom,$mon,$year,$wday,$yday,$isd) = localtime(time);
	my $timestamp = sprintf("%3s %3s %02d %4d  %02d:%02d:%02d",
$days[$wday],
		$months[$mon], $dom, $year+1900, $hour, $min, $sec);

	return $timestamp;
} 

# be sure routes are set via appropriate gateways to test IPs 
# ___________________________________________________________

$checkro = `$ip ro ls`;
if (!($checkro =~ /$tip1/)) {
	system ("$ip ro add to $tip1 via $gw1 src $src1 proto static");
}
if (!($checkro =~ /$tip2/)) {
	system ("$ip ro add to $tip2 via $gw2 src $src2 proto static");
}

# test if $gw1 and/or $gw2 currently in table $tab
# ________________________________________________

$checkgw = qx/$ip ro ls tab $tab/;

if ($checkgw =~ /$gw1/) {
	$check1 = 1;
} else {
	$check1 = 0;
}

if ($checkgw =~ /$gw2/) {
	$check2 = 1;
} else {
	$check2 = 0;
}

# ping the test IPs $tip1 and $tip2
# _________________________________

$p = Net::Ping->new("icmp");
if ($p->ping($tip1)) {
	$live1 = 1;
} else {
	$live1 = 0;
}
$p->close();
$p = Net::Ping->new("icmp");
if ($p->ping($tip2)) {
	$live2 = 1;
} else {
	$live2 = 0;
}
$p->close();

# If the current default in table $tab does not match the ping results then
# if only one route''s test IP is pingable change the default to that
route
# or if both test IPs are pingable change the default to use both
# or if neither test IPs are pingable change the default to use both 
# (might as well continue to try them, if we''re not going anywhere
anyway)
# _________________________________________________________________________

if (($check1 != $live1)||($check2 != $live2)) {
	if ((($live1 == 1)&&($live2 == 1))||(($live1 == 0)&&($live2 ==
0))) {
		system ("$ip ro ap default tab $tab proto static nexthop via $gw1 dev
$dev1 weight $wei1 nexthop via $gw2 dev $dev2 weight $wei2");
	} elsif (($live1 == 1)&&($live2 == 0)) {
		system ("$ip ro ap default tab $tab proto static via $gw1 dev
$dev1");
	} elsif (($live1 == 0)&&($live2 == 1)) {
		system ("$ip ro ap default tab $tab proto static via $gw2 dev
$dev2");
	} else {
		die ("value out of bounds\n");
	}
	system ("$ip ro del default tab $tab");
	system ("$ip ro flush cache");
}

# log
# ___

if (($live1 == 1)&&($live2 == 1)) {
	$log = "both UP";
} elsif (($live1 == 0)&&($live2 == 0)) {
	$log = "both DOWN (set UP)";
} elsif (($live1 == 1)&&($live2 == 0)) {
	$log = "$gw1 up, $gw2 DOWN";
} elsif (($live1 == 0)&&($live2 == 1)) {
	$log = "$gw2 up, $gw1 DOWN";
}

open(LOG, ">>$logfile");
print LOG &TimeStamp . " - $log\n";
close(LOG);

# double check that only one default is set
# _________________________________________

$checkdup = qx/$ip ro ls tab $tab/;
if ($checkdup =~ /default.*default/s) {
	system ("$ip ro del default tab $tab");
}

Whit Blauvelt

2002-Feb-20 04:58 UTC

head link

Re: Perl script to adjust default routing on 2 Net connections

More fixed. Simpler logic on appending. Deletes only if append has worked.
An allows setting the number of pings to try and the number of those that
must be good.

Whit

--- cut ---
#!/usr/local/bin/perl

# checkroutes.pl version 0.06, 18 Feb. 2002, whit@transpect.com
# Extends stock Nano-Howto setup with upstream route accessibility checking
# See http://www.linuxvirtualserver.org/~julian/nano.txt and patches at
# http://www.linuxvirtualserver.org/~julian/#routes
# (if not using Julian''s patchs, remove "proto static"
occurrences below)

# Run from cron (set with "crontab -e")
# example: "0-59/2 * * * * /path/to/checkroutes.pl" runs this every 2
minutes

# Best IPs to test for general use may be last IPs at ISPs before routing out to
Net
# Best IP to test if a single remote site is most important is that
site''s

# If perl not at /usr/local/bin/perl change first line to point to it

# Before running install Net::Ping from http://freeware.roobik.com/netping/
# (untar, cd to directory, "perl Makefile.PL; make; make install")

use Net::Ping;

# User settings
# _____________

$ip	= "/usr/sbin/ip";	# Location of "ip" on system

$gw1 	= "";	# Gateway 1 IP
$dev1	= "";		# Device (e.g., eth1)
$tip1	= "";	# Upstream IP to test
$src1	= "";	# Source address for outgoing packets
$wei1	= "1";			# Weight

$gw2	= "";	# Gateway 2 IP
$dev2	= "";		# Device (e.g., eth2)
$tip2	= "";	# Upstream IP to test
$src2	= "";	# Source address for outgoing packets
$wei2	= "1";			# Weight

$pings	= "1";			# Number of pings to send
$good	= "1";			# Number of pings that must be good

$tab	= "222";		# Table to set routes in

$logfile = "/var/log/checkroutes.log"; # File to log messages to 

# create timestamp for log
# ________________________

sub TimeStamp {

	# subroutine to create a "nice" looking timestamp
	# that doesn''t rely on the system''s ''date''
command

	my @days =
(''Sun'',''Mon'',''Tue'',''Wed'',''Thu'',''Fri'',''Sat'');
	my @months =
(''Jan'',''Feb'',''Mar'',''Apr'',''May'',''Jun'',''Jul'',''Aug'',''Sep'',
		''Oct'',''Nov'',''Dec'');

	my ($sec,$min,$hour,$dom,$mon,$year,$wday,$yday,$isd) = localtime(time);
	my $timestamp = sprintf("%3s %3s %02d %4d  %02d:%02d:%02d",
$days[$wday],
		$months[$mon], $dom, $year+1900, $hour, $min, $sec);

	return $timestamp;
} 

# be sure routes are set via appropriate gateways to test IPs 
# ___________________________________________________________

$checkro = `$ip ro ls`;
if (!($checkro =~ /$tip1/)) {
	system ("$ip ro add to $tip1 via $gw1 src $src1 proto static");
}
if (!($checkro =~ /$tip2/)) {
	system ("$ip ro add to $tip2 via $gw2 src $src2 proto static");
}

# test if $gw1 and/or $gw2 currently in table $tab
# ________________________________________________

$checkgw = qx/$ip ro ls tab $tab/;

if ($checkgw =~ /$gw1/) {
	$check1 = 1;
} else {
	$check1 = 0;
}

if ($checkgw =~ /$gw2/) {
	$check2 = 1;
} else {
	$check2 = 0;
}

# ping the test IPs $tip1 and $tip2
# _________________________________

$i=0;
$p = Net::Ping->new("icmp");
while ($i < $pings) {
	if ($p->ping($tip1)) {
		$ping1++;
	}
	$i++;
}
$p->close();

if ($ping1 >= $good) {
	$live1 = 1;
} else {
	$live1 = 0;
}

$i=0;
$p = Net::Ping->new("icmp");
while ($i < $pings) {
	if ($p->ping($tip2)) {
		$ping2++;
	}
	$i++;
}
$p->close();

if ($ping2 >= $good) {
	$live2 = 1;
} else {
	$live2 = 0;
}

# If the current default in table $tab does not match the ping results then
# if only one route''s test IP is pingable change the default to that
route
# or if both test IPs are pingable change the default to use both
# or if neither test IPs are pingable change the default to use both 
# (might as well continue to try them, if we''re not going anywhere
anyway)
# _________________________________________________________________________

# append new default route
# ________________________

if (($check1 != $live1)||($check2 != $live2)) {
	if (($live1 == 1)&&($live2 == 0)) {
		system ("$ip ro ap default tab $tab proto static via $gw1 dev
$dev1");
	} elsif (($live1 == 0)&&($live2 == 1)) {
		system ("$ip ro ap default tab $tab proto static via $gw2 dev
$dev2");
	} else {
		system ("$ip ro ap default tab $tab proto static nexthop via $gw1 dev
$dev1 weight $wei1 nexthop via $gw2 dev $dev2 weight $wei2");
	}
}

# delete and flush old default route if second has been appended
# ______________________________________________________________

$checkdup = qx/$ip ro ls tab $tab/;
if ($checkdup =~ /default.*default/s) {
	system ("$ip ro del default tab $tab");
	system ("$ip ro flush cache");
}

# log
# ___

if (($live1 == 1)&&($live2 == 1)) {
	$log = "both UP";
} elsif (($live1 == 0)&&($live2 == 0)) {
	$log = "both DOWN (set UP)";
} elsif (($live1 == 1)&&($live2 == 0)) {
	$log = "$gw1 up, $gw2 DOWN";
} elsif (($live1 == 0)&&($live2 == 1)) {
	$log = "$gw2 up, $gw1 DOWN";
}

open(LOG, ">>$logfile");
print LOG &TimeStamp . " - $log\n";
close(LOG);

bert hubert

2002-Feb-24 10:10 UTC

head link

Re: Perl script to adjust default routing on 2 Net connections

On Tue, Feb 19, 2002 at 11:58:46PM -0500, Whit Blauvelt
wrote:> More fixed. Simpler logic on appending. Deletes only if append has worked.
> An allows setting the number of pings to try and the number of those that
> must be good.
Do you have a URL for this script? I want to add it to the HOWTO but want to
retain your ability to edit it without going through me.

Regards,

bert

-- 
http://www.PowerDNS.com          Versatile DNS Software & Services
http://www.tk                              the dot in .tk
http://lartc.org           Linux Advanced Routing & Traffic Control HOWTO

LARTC - Jan 2002 - help with config for multiple internet connections

help with config for multiple internet connections

Re: help with config for multiple internet connections

Perl script to adjust default routing on 2 Net connections

Re: Perl script to adjust default routing on 2 Net connections

Re: Perl script to adjust default routing on 2 Net connections

Re: Perl script to adjust default routing on 2 Net connections