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New Member

MPLS L3VPN BGP AS Number

Hi,

I use "Cisco IOS Cookbook" from O'Reilly.

In its MPLS L3VPN example, it assigns "BGP 100" (a public AS number) to routers in MPLS cloud, and private AS numbers to CE routers.

I want to follow this example for readability in a real project, but was wondering if I should use a private AS number instead. (for PE routers.)

Our organization doesn't have a public AS number yet. Even if we have, I think we will get a new router dedicated for public internet AS exchange. 

So will I be fine if I use "BGP 100" on our PE routers?

 

Thanks,

-Andrew

 

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New Member

Andrew,I am curious as to

Andrew,

I am curious as to which example you are following, but I can say this, BGP sessions to the same ASN will be considered iBGP connections, BGP connections to another BGP ASN will be considered eBGP connection.  So if you have a "real" ASN assigned You will most likely have to re-configure you iBGP connections.  There may be a workaround like the "local-as".

ASN100 does really exist on the internet, so I would advise against using 100.

 

--Tim

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New Member

Andrew,I am curious as to

Andrew,

I am curious as to which example you are following, but I can say this, BGP sessions to the same ASN will be considered iBGP connections, BGP connections to another BGP ASN will be considered eBGP connection.  So if you have a "real" ASN assigned You will most likely have to re-configure you iBGP connections.  There may be a workaround like the "local-as".

ASN100 does really exist on the internet, so I would advise against using 100.

 

--Tim

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