# BGP AS Numbers for a Private MPLS/VPN Backbone

DevFeed: [BGP AS Numbers for a Private MPLS/VPN Backbone](<https://devfeed.tech/articles/bgp-as-numbers-for-a-private-mpls-vpn-backbone-10955.md>)

Original publisher: [Read original article](<https://blog.ipspace.net/2024/03/asn-private-mpls-backbone/>)

Published: 2024-03-13T07:30:00Z

Content type: article

Language: en

Sources: [ipSpace.net blog](<https://devfeed.tech/sources/ipspace-net-blog.md>)

Topics: [BGP](<https://devfeed.tech/topics/bgp.md>), [MPLS VPN](<https://devfeed.tech/topics/mpls-vpn.md>), [Virtual Private Network](<https://devfeed.tech/topics/vpn.md>), [Firewall](<https://devfeed.tech/topics/firewall.md>), [Internet](<https://devfeed.tech/topics/internet.md>)

Tags: [bgp](<https://devfeed.tech/tags/bgp.md>), [design](<https://devfeed.tech/tags/design.md>), [firewall](<https://devfeed.tech/tags/firewall.md>), [internet](<https://devfeed.tech/tags/internet.md>), [mpls-vpn](<https://devfeed.tech/tags/mpls-vpn.md>), [vpn](<https://devfeed.tech/tags/vpn.md>)

## AI overview

The article explains how to choose public or private AS numbers for a private MPLS/VPN backbone. It recommends using a private ASN when edge eBGP sessions connect the backbone to external ISPs, removing the private ASN from the public AS path, and assigning unique private ASNs to sites rather than VPNs.

## Source excerpt

One of my readers was building a private MPLS/VPN backbone and wondered whether they should use their public AS number or a private AS number for the backbone. Usually, it doesn't matter; the deciding point was the way they want to connect to the public Internet: We also plan to peer with multiple external ISPs to advertise our public IP space not directly from our PE routers but from dedicated Internet Routers, adding a firewall between our PEs and external Internet routers. They could either run BGP between the PE routers, firewall, and WAN routers (see BGP as High-Availability Protocol for more details) or run BGP across a bump-in-the-wire firewall: Read more ...