BGP dynamic routing in neutron - No Info about capability to receiv/learn dynamic routes

[Marc Luethi]

This bug tracker is for errors with the documentation, use the following as a template and remove or add fields as you see fit. Convert [ ] into [x] to check boxes:

- [x] This is a doc addition request.

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Release: 15.1.0.dev508 on 2019-06-19 22:16:58
SHA: 0c4c33b420ec98cb72adab09b87da0b62696a2ba
Source: https://opendev.org/openstack/neutron/src/doc/source/admin/config-bgp-dynamic-routing.rst
URL: https://docs.openstack.org/neutron/latest/admin/config-bgp-dynamic-routing.html

Hi all

(Network admin speaking) Our Openstack architect directed me here (https://docs.openstack.org/neutron/latest/admin/config-bgp-dynamic-routing.html), because he didn't know it for sure.

I was looking for information about the capabilities of the given BGP speaker in neutron. First assumption was that the BGP speaker would be offer a full BGP implementation.

However, I come to notice that while the documentation states clearly that advertising floating IPs and tenant networks is possible, it appears to neglect to state if receiving/learning routes from upstream BGP neighbors (in extenso: provider routers) is a) possible at all, b) partially possible, or c) only if using a particular or additional BGP capable software module that might have to be added to all nodes of relevance, and d) if possible, how to configure or activate this capability.

Not being capable to receive/learn dynamic routing information is a considerable limitation of functionality for a "BGP speaker"; it might be worthwhile to mention this expressedly.

Thank you for considering to add a small section to the documentation that clarifies this.

Marc

[Yusuf Güngör (yusuf2)]

+1 for this documentation request. Does anybody know the answer for that question?

Receiving/Learning routes from upstream BGP neighbors (in extenso: provider routers) is

a) possible at all
b) partially possible
c) only if using a particular or additional BGP capable software module that might have to be added

and if possible, how to configure or activate this capability?

[Yusuf Güngör (yusuf2)]

Source code has a comment on file ./neutron-dynamic-routing/neutron_dynamic_routing/services/bgp/agent/driver/os_ken/driver.py

        # Notify os-ken about BGP Speaker addition.
        # Please note: Since, only the route-advertisement support is
        # implemented we are explicitly setting the bgp_server_port
        # attribute to 0 which disables listening on port 179.

Also "OpenInfra Foundation" youtube video about "Neutron and BGP Dynamic Routing" has Q&A section ans developers states that bgp learning is not implemented yet: https://youtu.be/njSwWckX7xI?t=1883