Two Internet ADSL lines and load balancing.

[muaiqel]

Hi,

I am a beginner in the world of routing and router commands. So, please I need your help as much as u can.

I have two 256 Kbps ADSL lines to provide internet connection to my organization. They are connected to our Cisco 3640 router via e0/0 and e0/1. Also, there is a load balancing between them equally.

But the problem is that the internet connection is too slow. When I try to ping our ISP from the router, it seems like one line is drop. I checked the two interfaces by using "show interface e0/0" and "show interface e0/1" and I found that one has all the traffic while other is not (I checked the 5 min input rate and 5 min outpt rate from the previous command). The strange thing is that sometimes the stopped one (which has 0 traffic) is begining to send again. and sometime it will take all the traffic. and the other one will take 0 traffic.

I checked also with our ISP to see if all line is up and running, and they say yes.

How to troublshoot my case? How to check wheather loadbalancing work or not? How to find where is the problem?

Please make your answer clear as much as u can. And I appretiate your help.

Thanks in advance.

[jeffrey.zhou]

you can check your routing table(show ip route) to check if there are two equal cost default route that pointed to these two ADSL lins. And the load balance in Cisco Routers is per-destination by defaul(fast switching) and not per-packet(process switching). And you can use trace to check if the packet had been distributed to these two lines because the trace packet generated by the router is proccessed switching and use per-packet load balance.