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New Member

Using the same AS in multiple locations - BGP

We have an ASN and we are publishing an IP network in our hosting in Brazil, now we are adding a new hosting in USA. Although we have IP connectivity between Brazil and USA we are not able in transport traffic that is coming from Internet over our private network. So we are interested in using the same ASN in both sites publishing a different IP network each one but keeping the traffic between sites over Internet.

I know that ther will be a problem when each site tries to reach the other because BGP will drop the route that ends in the same AS. I hope to solve this issue with a static default route in each site.

Do you know a better solution? Do you think that it will work properly?

3 REPLIES
New Member

Re: Using the same AS in multiple locations - BGP

Here is a good link on setting up BGP:

http://www.cisco.com/univercd/cc/td/doc/cisintwk/ics/icsbgp4.htm

If this does not answer your question, you might want to open a TAC case so that an engineer can look through your configs.

New Member

Re: Using the same AS in multiple locations - BGP

ASN is public or Private .

If Private ISP will over-write it and Both USA and Brazil will be able to get Published prefixes.

Also you can put filter to avoid ur adv Prefixes back to ur self .

But if these are Public than using same ASN is not a good idea. Statci route will be the best option .

Regards,

New Member

Re: Using the same AS in multiple locations - BGP

If u have IP Connectivity between both sites you can use same ASN cause TCP session only needs IP connectivity even if they are using Public AS(IBGP TTL is be default 255) . They could be IBGP neighbors to each other and can advertise prefixes to each other also If you have EBGP session with ISP you make sure to Adv same routes to ISP and EBGP will be prefered over IBGP .

Any Thoughts ?

Regards,

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