32-bit ASNs

Lathrop, Andrew 1 Reputation point
2020-09-11T16:57:56.447+00:00

I am try to get BGP working on Windows Server 2019 Datacenter

I've gotten the Routing and Remote Access role installed. But when I try to use the Add-BgpRouter command (or the Set-BgpRouter command) in PowerShell, I've found the LocalASN parameter (as well as the PeerASN parameter) only allow 16-bit ASNs. Now both of those have an unsigned 32-bit integer as the data type, so there's no reason it shouldn't be accepted

Digging further, I found that the PS_BgpRouter_v1.0.cdxml file (located in C:\Windows\System32\WindowsPowerShell\v1.0\Modules\RemoteAccess) has a validater that limits the number to be no larger than 65534.

Now it's rather concerning that Windows server doesn't seem to support 32-bit ASNs they are pretty widely used, both internally and across the internet

It's also confusing whether or not 32-bit ASNs are officially supported by Microsoft. This issue on git https://github.com/MicrosoftDocs/windows-powershell-docs/issues/962 has a user say 32-bit ASNs are not supported, then links to a commit which changes the documentation from not mentioning 32-bit ASNs to saying it does support 32-bit ASNs

So my questions are:

Are 32-bit ASNs in BGP supported by Microsoft?
If so, why doesn't the Add-BgpRouter cmdlet support it? Is that just a mistake?
Are there any additional ways to configure BGP besides PowerShell? Like a GUI, CLI, or even just a text file

Windows Server 2019
Windows Server 2019
A Microsoft server operating system that supports enterprise-level management updated to data storage.
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  1. Andy YOU 3,076 Reputation points
    2020-09-14T15:01:26.817+00:00

    HI
    "Digging further, I found that the PS_BgpRouter_v1.0.cdxml file (located in C:\Windows\System32\WindowsPowerShell\v1.0\Modules\RemoteAccess) has a validater that limits the number to be no larger than 65534"
    1."Are 32-bit ASNs in BGP supported by Microsoft?"
    No,i also think it not support now .from above your description, i think you have found the reason. The reason is that BgpRouter_v1.0.cdxml limit the number to be no larger than 65534 and this file is older than current BGP technical requirements.

    2.if we update the latest powershell version ,will the same issue happen ?
    Installing PowerShell on Windows
    https://video2.skills-academy.com/en-us/powershell/scripting/install/installing-powershell-core-on-windows?view=powershell-7
    3.I think if you use 16-bit ASNs in BGP ,it will be also compatibled with the 32-bit AS in BGP.
    BGP Implementation Using 32-bit AS Number Configuration Example
    https://www.cisco.com/c/en/us/support/docs/ip/border-gateway-protocol-bgp/113593-config-bgp-using-32bit-ASN-00.html

    4.Are there any additional ways to configure BGP besides PowerShell?
    I haven't seen other method to configure BGP in windows platform, so powershell is only way.

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