We help IT Professionals succeed at work.

We've partnered with Certified Experts, Carl Webster and Richard Faulkner, to bring you a podcast all about Citrix Workspace, moving to the cloud, and analytics & intelligence. Episode 2 coming soon!Listen Now


Linux Networking question

ericho asked
Medium Priority
Last Modified: 2010-03-18

I have been trying to setup EQL (load balancing) on my Slackware 3.3 machine, and I have read the NET3-HOW-TO and
followed the procedures, but it seems like that HOW-TO is
too outdated that I couldn't get anything to work.

Can someone give me some detail instructions or point me to
a web page or a good HOW-TO ?

Best Regards,
Eric Ho
Watch Question

I am going to attempt to answer this, with one thing in mind, over here in Australia at least you will be hard pressed to find too many service providers which will use EQL.
      Do you understand what it is?  I shall explain just in case.
EQL is a way of using two links from your computer to your Internet Service Provider, (it must support the feature)  essentially it is like having one modem receiving from one computer and the other transmitting to the other computer, and vice versa on the other end.
So you effectively you double your data throughput speed.
But unless you have the two links, etc. you will not be able to connect, because your modem will be trying to be just a transmit or just a receive, because it has not been configured for it's proper mode, of duplexing.  SO you should not enable this feature when you recompile the kernel.

If your question is along the lines of, YES you do need the EQL and you want to therefore know how to set it up , well what you have to do is compile a kernel with EQL support in it.  You should read up on compiling a new kernel, and the option for the EQL is in the Network device support section.
If you require instructions on how to compile the kernel, then I shall post that when you respond, otherwise I hope that kind of covers what you were after, if not, sorry...



- I know what load balancing with multiple serial lines is, I have done it before with Win95.
- I have compiled the kernel with EQL support
- I can establish 2 PPP links with 2 modems (ppp0, ppp1) using ttyS0 and ttyS1
- I have also added a static route (eql) after the 2 ppp connections have established

Hum....I guess I will do everything over again tonight to see if I did anything stupid :(
Thanks for trying to help anyway.

Best Regards,
Eric Ho

Do you possibly have to have two static routes, or instead of adding a default gateway or net with  route add net  x.x.x.x
howabout route add host x.x.x.x
or instead of route add gw default
use route add gw x.x.x.x  using the ip addr of one modem or two lots of the same statement with two seperate devices.

Sorry I couldn't offer more than that since I have nevet atually used EQL so I do not know how the routing table is organised.

there is my setup for 4 modems, i use cyclades card, then you have to relace cubX by ttySX, and have to modify the phone number, and parameter, mtl1 mtl2 etc, and execute script the number of the time you need to :-), then for 2 modems, you have to execute it like this twice : ppp-on.4line mtl1 and ppp-on.4line mtl2, will ethablish 2 connection over the net on load balancing
there is my script

#       ppp-on
#       Set up a PPP link
if [ "$1" = "mtl1" ] ; then
elif [ "$1" = "mtl2" ] ; then
elif [ "$1" = "mtl3" ] ; then

elif [ "$1" = "mtl4" ] ; then

        echo mtl1 or mtl2 or mtl3 or  mtl4
OPTIONS='lcp-echo-interval 15 lcp-echo-failure 2'

/usr/lib/ppp/fix-cua $DEVICE
echo ppp-on: `date` call in 30 seconds... >>/var/adm/messages
sleep 30

if /usr/lib/ppp/pppd $OPTIONS \
        asyncmap 0 -detach modem crtscts mru 296 $OUR_IP_ADDR: \
        connect "/usr/lib/ppp/chat-ppp $PHONE $USER $PASSWORD" \
        /dev/$DEVICE $BAUD
        echo Connection Lost >>/var/adm/syslog
        echo !!!!!!!!!!!! connection Fail !!!!!!!!!!! >>/var/adm/syslog
in regard
good luck

Not the solution you were looking for? Getting a personalized solution is easy.

Ask the Experts

oups i forgot the file  chat-ppp...
there is the file
/usr/lib/ppp/chat -v ABORT "NO CARRIER" ABORT BUSY  "" ATZ0 OK ATD$PHONE CONNECT "" ogin:--ogin: $USER ssword: \\q$PASSWORD
if you dont have this file, the load balancing will not work
in regard
Access more of Experts Exchange with a free account
Thanks for using Experts Exchange.

Create a free account to continue.

Limited access with a free account allows you to:

  • View three pieces of content (articles, solutions, posts, and videos)
  • Ask the experts questions (counted toward content limit)
  • Customize your dashboard and profile

*This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.


Please enter a first name

Please enter a last name

8+ characters (letters, numbers, and a symbol)

By clicking, you agree to the Terms of Use and Privacy Policy.