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New Member

wan link redundency and load balancing

Hi, I have 3750 on each end of my location .

i have 2 wan link on ethernet one is of 45 Mb and other is of 20 Mb both from diff ISP.

Please suggest me the configuration i shoud go ahead to achive load balance and redundency on wan links.

by business requires continus connectivity this connectivity should not loose any session.

Please help me achive this.

Prasad.Patkar@rediffmail.com

8 REPLIES

Re: wan link redundency and load balancing

Hi Prasad,

Are you running any routing protocol between these two sites.

As both the WAN links are dedicated ones, the redundancy part will be taken care by the routing protocol.

As the links are unequal in bandwidth, if you are running EIGRP as your IGP, then you have the option to do unequal cost load balancing.

Revert back to us if you need more clarification.

-VJ

New Member

Re: wan link redundency and load balancing

Hi VJ,

Thanks for u r reply.

will eigrp help me in maintaining existing session.

can you give me sample configuration.

Thanks.

Prasad.Patkar@rediffmail.com

Cisco Employee

Re: wan link redundency and load balancing

Prasad,

I believe these coonects are private conections between the 2 sites.

EIGRP will work in your case.Please look at the EIGRP design guide below and should help you incase.

http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a008009437d.shtml

http://www.cisco.com/en/US/tech/tk365/technologies_white_paper09186a0080094cb7.shtml

HTH,

-amit singh

Re: wan link redundency and load balancing

Hi,

Yes. With EIGRP, you can do unequal cost load balancing.

Have a look at this URL for a theoretical background on the same.

http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a008009437d.shtml

Hope this helps. Kindly rate the post, if it was helpful.

-VJ

Re: wan link redundency and load balancing

Dear

Load balance between tow providers easy but how about your address scenario, are you have your own IP address (PI)? or you NAT your private with by the providers pools?

Best Regards,

Mounir Mohamed

New Member

Re: wan link redundency and load balancing

It is purely L-2 ( Ethernet )connectivity from both of my ISP's.

Can i use Etherchannel Bundulling for unequal BW Link .

Thaks,

Prasad Patkar.

Cisco Employee

Re: wan link redundency and load balancing

Prasad,

If your port configurations are exactly same i.e the trunk configurations,Speed,Duplex etc. then it should work for you. Practically I havent tried but it should work for you keeping in mind that ISP's has allowed PAgp or LACP control traffic end-end.

-amit singh

New Member

Re: wan link redundency and load balancing

Hi,

If you use ospf routing protocol between two sites, you can have redundancy and load balancing but max through put will be 20+20 = 40 mbps only (less than 45 mpbs!). If you have any idea about traffic pattern, you can statically route few segments separately.

Thanks

Karunakar

NIC

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