Linux Scripting

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mejam
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Linux Scripting

Post by mejam »

Hy all...I am new to scripting...i need a linux script that will do both Load Balancing and Fail over for my network....I am running CentOS on my server and i have two DSL modems....Please help...!!


Regards

Abdulrehman
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Abdulrehman
LinuxFreaK
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Re: Linux Scripting

Post by LinuxFreaK »

Dear mejam,
Salam,
mejam wrote:Hy all...I am new to scripting...i need a linux script that will do both Load Balancing and Fail over for my network....I am running CentOS on my server and i have two DSL modems....Please help...!!
FYI, http://lnlb.sourceforge.net and http://blog.taragana.com/index.php/arch ... -on-linux/

Best Regards.
Farrukh Ahmed
mejam
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Post by mejam »

Dear Farrukh bhai,
Thanks for ur help but i have already gone through these links...nothing good working for me...that why i asked for a complete script.. :cry:
Regards
Abdulrehman
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Post by x2oxen »

Well that thing worked for me why its not working for you? You missing anything?
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mejam
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Post by mejam »

aaah...figured it out....thanks for help..
Regards
Abdulrehman
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Post by lambda »

please share your script so that others can use it.
Watch out for the Manners Taliban!
Isn't it amazing how so many people can type "linuxpakistan.net" into their browsers but not "google.com"?
mejam
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Post by mejam »

This scrip it for load balancing only.....mentioned link will guide about fail over
http://blog.taragana.com/index.php/arch ... -on-linux/
======================================================================
#!/bin/bash
#
# bal_local Load-balance internet connection over two local links
#
# Author: Abdulrehman <arvagabond5@gmail.com>
#

# Set devices:
DEV1=${1-eth0} # default eth0
DEV2=${2-eth1} # default eth1

# Get IP addresses of our devices:
ip1=`ifconfig $DEV1 | grep inet | awk '{ print $2 }' | awk -F: '{ print $2 }'`
ip2=`ifconfig $DEV2 | grep inet | awk '{ print $2 }' | awk -F: '{ print $2 }'`

# Get default gateway for our devices:
gw1=`route -n | grep $DEV1 | grep '^0.0.0.0' | awk '{ print $2 }'`
gw2=`route -n | grep $DEV2 | grep '^0.0.0.0' | awk '{ print $2 }'`

echo "$DEV1: IP=$ip1 GW=$gw1"
echo "$DEV2: IP=$ip2 GW=$gw2"

### Definition of routes ###

# Check if tables exists, if not -> create them:
if [ -z "`cat /etc/iproute2/rt_tables | grep '^251'`" ] ; then
echo "251 rt_dev1" >> /etc/iproute2/rt_tables
fi
if [ -z "`cat /etc/iproute2/rt_tables | grep '^252'`" ] ; then
echo "252 rt_dev2" >> /etc/iproute2/rt_tables
fi

# Define routing tables:
ip route add default via $gw1 table rt_dev1
ip route add default via $gw2 table rt_dev2

# Create rules:
ip rule add from $ip1 table rt_dev1
ip rule add from $ip2 table rt_dev2

# If we already have a 'nexthop' route, delete it:
if [ ! -z "`ip route show table main | grep 'nexthop'`" ] ; then
ip route del default scope global
fi

# Balance links based on routes:
ip route add default scope global nexthop via $gw1 dev $DEV1 weight 1 nexthop via $gw2 dev $DEV2 weight 1

# Flush cache table:
ip route flush cache

# All done...
=======================================================================
Regards
Abdulrehman
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Post by nomankhn »

mejam wrote:This scrip it for load balancing only.....mentioned link will guide about fail over
http://blog.taragana.com/index.php/arch ... -on-linux/
======================================================================
#!/bin/bash
#
# bal_local Load-balance internet connection over two local links
#
# Author: Abdulrehman <arvagabond5@gmail.com>
#

=======================================================================
Are u the author of this script? its great, tell us what problem come so u not able to use initially and how u resolve that.

Thanks,
Noman Liaquat
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Post by x2oxen »

According to your this script i think that gwping script also needed to be modified. But this above script looks like a great piece of work. Who wrote that?
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Post by mejam »

i wrote it with the help of a scripting professional....i have his CBTs of scripting...i could not have done this on my own....
Regards
Abdulrehman
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Post by mejam »

my machine was having a troubble...when it gets rebooted it shifted the LAN interfaces...eth0 became eth1 and eth1 turns to eth0....i just figured it out and fixed it....there was nothing wrong with the script at that time even
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Abdulrehman
mejam
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Post by mejam »

and thats strange that i did not get any comments from farrukh bhai......? :D
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Abdulrehman
lambda
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Post by lambda »

why is it strange?
Watch out for the Manners Taliban!
Isn't it amazing how so many people can type "linuxpakistan.net" into their browsers but not "google.com"?
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Post by shakirz1 »

to stop lan card shifting put mac addresses of lan card in /etc/sysconfig/network-scripts/ifcfg-ethx.
mejam
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Post by mejam »

Thanks for help buddy but i already have figured it out...things are just running fine... :)
Regards
Abdulrehman
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