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New Member

Load Balance


I have 2 routers, one 3640 with IOS (tm) 3600 Software (C3640-I-M), Version 12.0(5)XK1 and a 2501 with IOS (tm) 2500 Software (C2500-I-L), Version 12.0(14), both are connected with 2 ppp links with 64K , how can I make a load balance between this 2 links?



New Member

Re: Load Balance


interface loopback0

ip address

interface serial0

ip unnumbered loopback0

no ip route-cache


ip load-sharing per-packet

interface serial1

ip unnumbered loopback0


And the same at other end with different ip host address for loopback address.

New Member

Re: Load Balance


I have just a few questions :

Need I put command enc ppp at serial 0 and serial 1 configuration ?

How I will write the route command for this configuration, for example, the ethernet address for the other end is and the address for loopback will be OK?

The router command will be ip route, that is right ?

Thanks for your attention,


New Member

Re: Load Balance

1)First learn two sets of same routes over the two interfaces. If both routes are learned via IGP (OSPF, ISIS, etc) then both routes will be installed automatically in your routing and forwarding table. If you are using BGP then some other tricks you have to use which I can discuss if need be

2)If both interfaces are unnumbered (as suggested by other reply) on both sides then have two static routes for each other loopbacks.

After the two entries are created then forwarding mechanism should load-share

based on default setting.

If CEF is being used then per packet or per soure-destination pair load balancing

can be done.

If route caching is used then per destination sharing will be done.

Search on CCO for exactly what kind of load-sharing you are desiring based on your


Hope this helps


New Member

Re: Load Balance


Now I have some questions :

1)I don't use IGP or BGP, I am using RIP, is there any problem ?

2)What is CEF ?

3)What kind of load-sharing I must use to connect the 2501 and 3640, the IOS of 2501 is IOS (tm) 2500 Software (C2500-I-L), Version 12.0(14), RELEASE SOFTWARE (fc1), the IOS of 3640 is IOS (tm) 3600 Software (C3640-I-M), Version 12.0(5)XK1, EARLY DEPLOYMENT RELEASE


4)I tried put the command ip load-sharing per-packet into serial 1 of 2501 but the command was unrecognized, what is wrong ?

5)If I undestood, I wil not use enc ppp into serial, that is right ?



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