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Can 32-bit ASN be dangerous/tricky in any way? We are currently implanting BGP in our network. One of the uplinks has emphasized that their ASN is 32-bit. Ours is 32-bits as well. What is it I should be paying attention to when dealing with 32-bit ASNs? I've already checked that our router's software supports it. Is there anything else to be checked?

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up vote 4 down vote accepted

32-bit ASNs are backwards compatible with 16-bit ASNs, and if you have a proper BGP implementation on your router 32-bit ASNs will be transported silently across your network. So 16-bit ASN routers do work with 32-bit routers and vice versa.

Where this would be tricky is a good question actually, since most of BGP just forwards stuff if there are new flags etc. that were introduced. The obvious issue would be broken implementations or non-standards behavior.

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