Help in eBGP when Two WAN IP from Same ISP dual Bandwidth 50MB and 25 MB in 3845 router

[csawest.dc]

Dear Experts,

Help in eBGP when Two WAN IP from Same ISP  dual Bandwidth 50MB and 25 MB in 3845 router.

i am confuse now please clearify it .

I have Two WAN ip from SAME ISP

WAN-1  1.1.1.1 255.255.255.252 ( 50 MB Bandwith)

WAN-2 2.2.2.2 255.255.255.252 ( 25 MB bandwidth)

ASN- 13101

My ASN : 123456
My Network : 101.145.125.0/22

I need to use both the bandwidth at a time and also if when any one WAN link goes down my all the traffic
work anather WAN autometic visa-versa (i not use one WAN is primary and one is secondery) both the primary but when
any one WAN bandwidth down my all the traffic up autometic working WAN link.

I am using Cisco 3845 Router.

Please help me and my bit request to clear my confution.

Thanks in ADV,

[Dan-Ciprian Cicioiu · Accepted solution]

Hello ,

Both wan links are into one router ?

I suppose that the ISP is sending same routes on both links. Then you can configure under the router bgp

maximum-paths 2 - equal cost.

But this way you will loadbalance only the traffic leaving from you.

Dan

[Mahesh Gohil · Accepted solution]

Hello,

When you are with BGP think about incoming and outgoing traffic

I assume that at both end links are terminating in same router if so

> Incoming: Two option

    1- You should advt. your /22 ip to both the link and ask your provide to configure maximum-path 2 option under global bgp

    2- You can create one BGP session on loopback and advt. /22 on that single bgp session.

       In both above case load will be shared and also if one goes down the traffic will be shifted to next link

> Outgoing:Two option

    1- Same as above you need to configure maximum-path 2 at your end bgp

    2- Same as above.

Now lets assume provider has two different router than second option will not be useful and you should divide /22 into two /23 pool and advt.

one /23 on one bgp session and other on next bgp session. In addition also advt. supernet of /22 on both the bgp so that if one link goes down you will have secondary path

Hope this helps

Regards

Mahesh

[csawest.dc]

Dear Mahesh,

Thanks to both of you for great help

i am using only 1 router in dual WAN ip from single ISP

So please mahesh as per my require and i already mention my all the details as above so please give me the to make BGP configure templates

it is very very help full me.

Thanks in ADV,

[Mahesh Gohil]

Hello,

If both end is having single router then it is very simple

router bgp 123456
neighbor 1.1.1.2 remote-as 13101
neighbor 2.2.2.1 remote-as 13101
network 101.145.125.0 mask 255.255.252.0
maximum-path 2

ip route 101.145.125.0 255.255.252.0 null0 220 >>>> Not required if above route (/22) is already in your routing table

also confirm from your ISP that they have same router at their end else config will be different

Hope this helps

Regards

Mahesh

[csawest.dc]

Dear Mahesh,

I Think most prob they have provide both the link from Different location two diffrent router  to in my single  Cisco 3845 router.

if suppose in this situation what configuration i need to config in my router as per my require and what i have to tell them for  they have to changes and required in their router as per my require.

Thanks in ADV,