This article details the ASNs reserved and used by Pureport and the cloud providers we connect to. It also provides guidance on what ASNs you may want to use, including:



ASNs Reserved and Used by Pureport and the Cloud Providers

The following table lists the ASNs used by Pureport and the cloud providers we connect to. 


Do not use any of these ASNs in networks that will peer with Pureport via BGP. If you already use one of the private ASNs listed below, check to see if your gateway router/firewall allows you to change or translate your ASN for the peering connection with Pureport.


ProviderASNNotes
Pureport394351Pureport uses the 4-byte public ASN 394351 for all BGP peering. You cannot change this ASN.
Azure8074, 8075, 12076Azure uses the public ASN 12076 for ExpressRoute peering, both private and Microsoft (public). You cannot change this ASN.
Azure (reserved)65515-65520Azure has reserved ASNs from 65515 to 65520 for internal use. Do not use any ASNs in this range for peering with Pureport if you plan to connect to Azure via ExpressRoute.
AWS (prior to June 30, 2018)17493, 10124, 9059, 7224AWS previously used the public ASNs 17493 (APAC/Singapore), 10124 (APAC/Tokyo), 9059 (EU/Ireland), and 7224 (everywhere else) for all DirectConnect peering.

Any VGW created before June 30, 2018 will use this ASN,.
AWS64512AWS defaults to the private ASN 64512 for DirectConnect peering to a Direct Connect Gateway or to a VGW created after June 30, 2018.

Although you can change this ASN when creating the VGW or Direct Connect Gateway and use any private ASN for the AWS side, we recommend leaving it set to the default.
Google Cloud Platform16550Google uses the ASN 16550 for all Google Cloud Interconnect peering. You cannot change this ASN.
Oracle Cloud64555Oracle Cloud reserved the private ASN 64555.
IBM Cloud (customer side)64999IBM defaults to the private ASN 64999 for the Customer-Side for DirectLink peering. You must change this ASN via ticket to the Pureport ASN: 394351.
IBM Cloud 13884IBM Cloud uses the public ASN 13884 for all peering via Direct Link.
Reserved by IANA
23456, 64496-64511, 65535-65551 and 429496729
These ASNs are reserved by IANA and should be avoided for use as a customer-side ASN.




Selecting an ASN for peering with Pureport

If you have a public ASN, we recommend that using it for all peering with Pureport. 


If not, select an ASN from the 2-byte private ASN range of 64512 and 65534, but do not use any of the reserved ASNs listed in the table above.



Multi-site Considerations

If you are connecting multiple sites to Pureport and configuring BGP peering for each, you can use the same ASN for each location. However, if you need the sites to communicate directly with one another on their native IP addressing (not using Cloud Grade NAT), you must confirm that your gateway device will accept BGP announcements containing the "local" AS number as part of the AS path. 


For example, on a Cisco router, the command used is the BGP sub-command: 

neighbor <IP ADDRESS> allowas-in


Note: Setting this command may disable part of the built-in BGP route loop prevention built into your gateway. To avoid this, use a different ASN for each location.



2-Byte vs. 4-Byte ASNs

The Pureport public ASN, used for all BGP peering with Pureport, is a 4-byte ASN and cannot be changed at this time. 


If your firewall or router does not support 4-byte ASNs (older firewalls and routers may only support 2-byte ASNs), we recommend using static routing with Pureport.