Primary and Backup route selection --- Pls help

[Dipesh Patel]

Dear all experts,

Thanks in advance.

I am confused about selcting the best path from One ISP as the primary and the second ISP as the secondary.

In Topology IGP = EIGRP and EGP = BGP.

BGP routes are redistributed in EIGRP.

From CORE how can I tune the path to go for Primary link i.e. TATA as shown in Topology in attached file.

By default it select the TATA from HAZ end but AIRTEL from MAH end.

Pls help to tune the path selection.

Other question is  my Airtel bandwidth is lower.

So when TATA link is down I want to allow only specific important traffic on Airtel link.

Pls help how can i do this.

The details are show in attached file with snaps.

Regards,

[Adrian Lazar]

Hi Dipesh,

If you want to use TATA as the primary provider you can simply modify the EIGRP metric when you redistribute BGP into EIGRP. You must configure a better metric for TATA routes so the Core will always choose this path.

From your description it seems that you do not want to have all traffic go via Airtel even if TATA is down. To only allow important traffic via Airtel you should simply only advertise those important routes to the Core, the other ones should be filtered. This way when TATA is down the Core will only know about the important routes and you will have only important traffic going through.

Hope this helps.

Adrian

[rafat0426]

Hi,

you need to manipulate routes at Destination end , kindly follow below steps.

HAZ END

at HAZ end Tata CE you will recieve this MAH routes as bgp from both Tata and Airtel , this routes you need to redistribute in eigrp while redistributing you can set metric as 1 in Tata end CE router and set metric 10 in Airtel End CE Router

so that when HAZ wants to reach MAH it will take Tata Link as this routes having less metric than Airtel Link , if Tata Goes Down you will have only Airtel routes in routing table so it will switch to Airtel as Backup

MAH END

same thing you have to do in MAH end TATA CE Router and AIRTEL CE Router, you need to give metric as  1 in Tata CE end router while redistributing n eigrp and metric in Airtel CE Router while redistributing.

it will take Tata as primary and airtel as backUP

2 CASE

for specific routes redistributing when Primary Link goes DOWN ,

while redistributing eigrp into BGP in both end Airtel CE Router you need use route map , under this route map you can assign access-list in acess-list you can define which route you have to advertise  .

those routes you have to give as permit in access-list , that is it other  routes will be blocked from advertising into BGP in Airtel Link.

kindly let me know is this help you , or need more specific information .

Thanks

Raffath