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New Member

Load sharing/loadbalencing ADSL links

Hi all

I have a internet router with 4 ADSL ports.Is there any method or seperate device to load balance or load share between these links.Thanks in advance.

8 REPLIES
Hall of Fame Super Silver

Re: Load sharing/loadbalencing ADSL links

Hello Anvar,

the routing part is relative easy:

four default static routes make the job

ip route 0.0.0.0 0.0.0.0 dialer1

ip route 0.0.0.0 0.0.0.0 dialer2

ip route 0.0.0.0 0.0.0.0 dialer3

ip route 0.0.0.0 0.0.0.0 dialer4

the most difficult part is to use NAT:

when accessing the internet private ip addresses need to be translated

given a 19268.10.0/24 internal lan you can use route-map based NAT

int fas0/0

ip nat inside

int dialer 1-4

ip nat outside

you can map 1/4 of hosts on each link

route-map nat-link1 permit 10

match ip address 1

set interface dialer1

route-map nat-link2 permit 10

match ip address 2

set interface dialer2

and son

where

access-list 1 permit 192.168.10.0 0.0.0.63

access-list 2 permit 192.168.10.64 0.0.0.63

access-list 3 permit 192.168.10.128 0.0.0.63

access-list 4 permit 192.168.110.192 0.0.0.63

ip nat inside source route-map nat-link1 interface dialer1 overload

ip nat inside source route-map nat-link2 interface dialer2 overload

ip nat inside source route-map nat-link3 interface dialer3 overload

ip nat inside source route-map nat-link4 interface dialer4 overload

Hope to help

Giuseppe

New Member

Re: Load sharing/loadbalencing ADSL links

Thanks very much Giuslar for the quick response.is it possible to bundle these links together and act as a single link

Hall of Fame Super Silver

Re: Load sharing/loadbalencing ADSL links

Hello Anvar,

>> is it possible to bundle these links together and act as a single link

yes with multilink PPP over ATM but all DSL links must be from a single provider and you need to work with them to make it working

see

http://www.cisco.com/en/US/docs/ios/qos/configuration/guide/mlppp_over_dial.html

Hope to help

Giuseppe

New Member

Re: Load sharing/loadbalencing ADSL links

Thanks Guiseppe for the link.

In the first case(witout multilink) is it possible to configure in such a way that even if one DSL link fails corresponding network be routed thru another ADSL link

Re: Load sharing/loadbalencing ADSL links

Hi

As you have used the interface in the 'ip route' statement, when the interface goes down, the route will disappear from the routing table giving you what you have asked for.

New Member

Re: Load sharing/loadbalencing ADSL links

Hi adamclarkuk

But each network is PATed to only one dialer interface and in the route map for this network destination is one dialer interface.In this scenario this will work?please clarify.

Re: Load sharing/loadbalencing ADSL links

Your right, I missed the route-maps in the config example. hmmmm, then I am not sure.

Hall of Fame Super Silver

Re: Load sharing/loadbalencing ADSL links

Hello Anvar,

very good note:

the solution I proposed needs to be tuned to achieve fault tolerance (if possible).

I have to think about it.

Hope to help

Giuseppe

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