New set-as-path BGP action, and support last AS for for setting AS path. #1148
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No major YANG version changes in commit bffc29b |
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Removed the extra comma and rebased against master. |
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| @@ -229,6 +236,19 @@ module openconfig-bgp-policy { | |||
| the IGP cost using the enum (predefined value)."; | |||
| } | |||
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| typedef bgp-as-mode-type { | |||
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We use the term 'builtin' in other parts of OC to refer to special values or logic that is defined by the device.
| typedef bgp-as-mode-type { | |
| typedef bgp-as-builtin-type { |
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| typedef bgp-set-as-path-option-type { | ||
| type enumeration { | ||
| // TODO(xqm): maybe use prepend instead? | ||
| enum ADD { |
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I am not so sure about certain behaviors after thinking about this a little more. Unlike communities, as-path is ordered and therefore could be a bit tricky.
- I wonder what would the expected behavior for
add as-path "1 2 3". Do we prepend "1 2 3" to the AS path? How about `delete as-path "1 2 3"? Do we delete 1) every AS1, AS2 and AS3 from the path 2) all "1 2 3" sub-paths from the as-path? - Using as-path-set reference as input might complicate things further. For instance, an as-path-set can have multiple members such as
["1 2", "3 4 5"]. Afterreplace as-path-set, will the AS path become"1 2 3 4 5"? If there are regex in as-path-set, maybe it works for delete, but it's more like invalid input for add/replace.
Would like to have your thoughts to better define the semantics in these cases. Thanks Darren!
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Regarding precedence, I am aware of as path prepending 'n' times, adding the "last-asn" to the list and replacing the originating asn with one's own asn (as-override) .
I'm not aware of existing implementations that allow arbitrary add/remove operations from an asn path.
Regarding "editing" an as-path set, practically in gNMI (although OC isn't gnmi only, netconf is also used), there is no 'list editing / insert' operation. To change an 'ordered-by-user' list in gnmi, the whole list must be replaced.
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Makes sense. Maybe we can remove the set-as-path-option and set-as-path-method altogether, since only replacing the whole list is supported. I also updated set-as-path to be a leaf-list under bgp-actions as it does not require other input now. Let me know if this looks better (or worse).
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| set-as-path action"; | ||
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| leaf-list as-paths { | ||
| type union { |
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I think this need to be ordered-by-user .
Is there precedence for this in existing implementations or is this intended to be a new feature request?
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Good call. Updated type with ordered-by user.
IIUC, only Arista support replacing the entire AS path with [set as-path match all replacement] (https://www.arista.com/en/um-eos/eos-acls-and-route-maps#xx1313923). This is the recommended Arista implementation for the existing as-path-expand in Juniper, which is also vendor specific unefortunately. I am not sure which one fits the model better (neither is ideal due to single-vendor support). set-as-path might be slightly more generic based on our past discussions. Kindly share your thoughts please.
| typedef bgp-set-as-path-option-type { | ||
| type enumeration { | ||
| // TODO(xqm): maybe use prepend instead? | ||
| enum ADD { |
There was a problem hiding this comment.
Regarding precedence, I am aware of as path prepending 'n' times, adding the "last-asn" to the list and replacing the originating asn with one's own asn (as-override) .
I'm not aware of existing implementations that allow arbitrary add/remove operations from an asn path.
Regarding "editing" an as-path set, practically in gNMI (although OC isn't gnmi only, netconf is also used), there is no 'list editing / insert' operation. To change an 'ordered-by-user' list in gnmi, the whole list must be replaced.
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| @@ -28,7 +28,14 @@ module openconfig-bgp-policy { | |||
| It augments the base routing-policy module with BGP-specific | |||
| options for conditions and actions."; | |||
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| oc-ext:openconfig-version "8.0.0"; | |||
| oc-ext:openconfig-version "8.2.0"; | |||
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Split the change for last-as support to #1221 as discussed offline, which takes version 8.1.0. This change is expected to merge after that PR, so we use version 8.2.0 after that.
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Change Scope
/routing-policy/policy-definitions/policy-definition/statements/statement/actions/bgp-actions/set-as-path(a list of ASNs or last-as)oc-bgp-polinstead ofoc-bgp-types.New paths after the model update:
Platform Implementations