[yang-doctors] How to restrict to have single control-plane-protocol instance

["Reshad Rahman (rrahman)" <[e-mail]>]

Hi YDs,

MSDP YANG authors want to enforce single-instance of MSDP control-plane protocol. The when “rt:type = ‘msdp’“ allows multiple control-pane-protocol instances as long as they have different rt:name. The only workaround I thought of is to have a when statement on the name in the top level container. This would still multiple control-plane-protocol instance of type msdp but restricts the name to a fixed name (msdp-protocol  in this case) for the top level msdp container to exist. Any suggestions on how to do this better?

Regards,
Reshad.

  augment "/rt:routing/rt:control-plane-protocols/"
        + "rt:control-plane-protocol" {
     when "rt:type = ‘msdp’"  {
      description
        "….”;
    }
    description "….";

    container msdp {
      when "../rt:name = ‘msdp-protocol’"  {
        description
          "….";
      }
      description "MSDP top level container.";


From: "Reshad Rahman (rrahman)" <[e-mail]>
Date: Monday, February 5, 2018 at 6:25 PM
To: Xufeng Liu <[e-mail]>, "[e-mail]" <[e-mail]>
Cc: "[e-mail]" <[e-mail]>, "Mahesh Sivakumar (masivaku)" <[e-mail]>, "[e-mail]" <[e-mail]>, "[e-mail]" <[e-mail]>, "[e-mail]" <[e-mail]>, "[e-mail]" <[e-mail]>, "[e-mail]" <[e-mail]>, "[e-mail]" <[e-mail]>, "Acee Lindem (acee)" <[e-mail]>
Subject: Re: Hi all, about the modification of MSDP YANG

Hi Sandy and Xufeng,

I understand that you want only 1 MSDP instance but I don’t think that justifies /rt:routing/rt:control-plane-protocols. If we do that we will end up with all single-instance protocols under /rt:routing/rt:control-plane-protocols and all the multi-instance ones under /rt:routing/rt:control-plane-protocols/rt:control-plane-protocol.

I am not sure what’s the best way to enforce single-instance, I can check with the other YDs on this topic. One way it can be done is as follows (I’ve added the when statement in bold to existing BFD model), it enforces that the protocol name is ‘bfdv1’. So multiple instances with rt:type=bfd-types:bfdv1 could be created, but only one of these instances can have the bfd container. This is probably not the best way but the point is that IMO protocols have to go under /rt:routing/rt:control-plane-protocols/rt:control-plane-protocol.

Regards,
Reshad.

  augment "/rt:routing/rt:control-plane-protocols/"
        + "rt:control-plane-protocol" {
     when "rt:type = 'bfd-types:bfdv1'"  {
      description
        "This augmentation is only valid for a control-plane protocol
         instance of BFD (type 'bfdv1').";
    }
    description "BFD augmentation.";

    container bfd {
      when "../rt:name = 'bfdv1'"  {
        description
          "This augmentation is only valid for a control-plane protocol
           instance of BFD (type 'bfdv1').";
      }
      description "BFD top level container.";

From: Xufeng Liu <[e-mail]>
Date: Monday, February 5, 2018 at 9:38 AM
To: "[e-mail]" <[e-mail]>
Cc: "Reshad Rahman (rrahman)" <[e-mail]>, "[e-mail]" <[e-mail]>, "Mahesh Sivakumar (masivaku)" <[e-mail]>, "[e-mail]" <[e-mail]>, "[e-mail]" <[e-mail]>, "[e-mail]" <[e-mail]>, "[e-mail]" <[e-mail]>, "[e-mail]" <[e-mail]>, "[e-mail]" <[e-mail]>
Subject: RE: Hi all, about the modification of MSDP YANG

Hi Sandy,

Thanks for the updates.

In RFC8022bis, the rt:type is defined under /rt:routing/rt:control-plane-protocols/rt:control-plane-protocol. If we augment /rt:routing/rt:control-plane-protocols, the “when” statement will not be valid, because it cannot find the rt:type. I don’t think that we need the “when” statement. The container with “presence” will serve the purpose of the identity. We can simply take out the “when” statement and the definition of the MSDP identity.

Thanks,
- Xufeng

From: [e-mail] [mailto:[e-mail]]
Sent: Monday, February 5, 2018 3:36 AM
To: Xufeng Liu <[e-mail]>
Cc: [e-mail]; [e-mail]; [e-mail]; [e-mail]; [e-mail]; [e-mail]; [e-mail]; [e-mail]; [e-mail]
Subject: RE: Hi all, about the modification of MSDP YANG


Hi Xufeng and Reshad,



I am sorry for forgetting the point. I updated the YANG model.

If no one has comments on it I'd like to submit the new version. :-)



Thanks,

Sandy
原始邮件
发件人： <[e-mail]<mailto:[e-mail]>>;
收件人： <[e-mail]<mailto:[e-mail]>>;张征00007940; <[e-mail]<mailto:[e-mail]>>; <[e-mail]<mailto:[e-mail]>>; <[e-mail]<mailto:[e-mail]>>; <[e-mail]<mailto:[e-mail]>>; <[e-mail]<mailto:[e-mail]>>;徐本崇10065053; <[e-mail]<mailto:[e-mail]>>; <[e-mail]<mailto:[e-mail]>>;
日 期 ：2018年02月03日 01:21
主 题 ：RE: Hi all, about the modification of MSDP YANG
Hi Sandy and Reshad,

The reason that we used to augment /rt:routing/rt:control-plane-protocols, instead of /rt:routing/rt:control-plane-protocols/rt:control-plane-protocol, is that we do not allow multiple instances of MSDP.

Thanks,
- Xufeng

From: Reshad Rahman (rrahman) [mailto:[e-mail]]
Sent: Friday, February 2, 2018 12:08 PM
To: [e-mail]<mailto:[e-mail]>; Xufeng Liu <[e-mail]<mailto:[e-mail]>>; [e-mail]<mailto:[e-mail]>; Mahesh Sivakumar (masivaku) <[e-mail]<mailto:[e-mail]>>; [e-mail]<mailto:[e-mail]>; [e-mail]<mailto:[e-mail]>; [e-mail]<mailto:[e-mail]>; [e-mail]<mailto:[e-mail]>; [e-mail]<mailto:[e-mail]>;  [e-mail]<mailto:[e-mail]>
Subject: Re: Hi all, about the modification of MSDP YANG

Hi Sandy,

I don’t know what warning you are getting now but from a quick look at the revision you sent I see couple of issues.

     identity msdp {
       base "rt:routing-protocol";  <== should be rt:control-plane-protocol
       description "MSDP";
     }
<snip>
     /*
      * Data nodes
      */
     augment "/rt:routing/rt:control-plane-protocols/rt:control-plane-protocol" {
        when "rt:type = 'MSDP'" { <== should be "rt:type = 'msdp:msdp'"


HTH,
Reshad.

From: "[e-mail]<mailto:[e-mail]>" <[e-mail]<mailto:[e-mail]>>
Date: Friday, February 2, 2018 at 4:37 AM
To: "[e-mail]<mailto:[e-mail]>" <[e-mail]<mailto:[e-mail]>>, "[e-mail]<mailto:[e-mail]>" <[e-mail]<mailto:[e-mail]>>,  "Mahesh Sivakumar (masivaku)" <[e-mail]<mailto:[e-mail]>>, "[e-mail]<mailto:[e-mail]>" <[e-mail]<mailto:[e-mail]>>, "[e-mail]<mailto:[e-mail]>"  <[e-mail]<mailto:[e-mail]>>, "[e-mail]<mailto:[e-mail]>" <[e-mail]<mailto:[e-mail]>>, "[e-mail]<mailto:[e-mail]>"  <[e-mail]<mailto:[e-mail]>>, "[e-mail]<mailto:[e-mail]>" <[e-mail]<mailto:[e-mail]>>, "[e-mail]<mailto:[e-mail]>"  <[e-mail]<mailto:[e-mail]>>
Cc: "Reshad Rahman (rrahman)" <[e-mail]<mailto:[e-mail]>>
Subject: FW: Hi all, about the modification of MSDP YANG


Hi all,



I deleted some groupings and make the model more clear.

And I updated the decription of (peer-as, up-time, expire).  Please review it.



A warning is still existing about rt:type:

5, - augment of control-plane-protocols is incorrect. There should be an identity msdp with

base "rt:routing-protocol" and then augment

"/rt:routing/rt:control-plane-protocols/rt:control-plane-protocol" with a when

statement. Take a look at OSPF YANG for an example.

[Sandy]: Added the identity and modify the augmentation, but it seems like there is no MSDP register in rt:type.

How can we register it?



Thanks,

Sandy
原始邮件
发件人：张征00007940
收件人： <[e-mail]<mailto:[e-mail]>>; <[e-mail]<mailto:[e-mail]>>;  <[e-mail]<mailto:[e-mail]>>; <[e-mail]<mailto:[e-mail]>>; <[e-mail]<mailto:[e-mail]>>; <[e-mail]<mailto:[e-mail]>>;徐本崇10065053;  <[e-mail]<mailto:[e-mail]>>; <[e-mail]<mailto:[e-mail]>>;
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日 期 ：2018年01月29日  17:04
主 题 ：Hi all, about the modification of MSDP YANG

Hi all,



YANG doctor Reshad had finished the early review about MSDP YANG.

I finished the preliminary modification version, please review it.

I think some advices from Reshad should be discussed:



1, - Not sure why peer-as is needed. Don't see it in RFC3618.

2, - leaf up-time, what's meant by "up time" in the description? Is it time it's

been created?

3, - description for leaf expire seems wrong.

[Sandy]: These items (peer-as, up-time, expire) doesn't existed in RFC3618, are these unnecessary? Please write down your

description if you insist on it. If nobody insist on it, should we delete them?



4, - Groupings are used for data which is used only once. Is this done on purpose or

was the intention to use those groupings more than once?

[Sandy]: These eight groupings are used only once, should we change them to container?

authentication-container;

global-config-attributes;

peer-config-attributes;

peer-state-attributes;

sa-cache-state-attributes;

statistics-container

statistics-error

statistics-queue



5, - augment of control-plane-protocols is incorrect. There should be an identity msdp with

base "rt:routing-protocol" and then augment

"/rt:routing/rt:control-plane-protocols/rt:control-plane-protocol" with a when

statement. Take a look at OSPF YANG for an example.

[Sandy]: Added the identity and modify the augmentation, but it seems like there is no MSDP register in rt:type.

How can we register it?





Most of the suggestion is adopted. The modification detail pls see below:



- Too many features (17)! Every piece of config has an if-feature statement.

Some of the configs (timers?) should be part of most/basic implementations, for

other config (e.g. authentication) I can see why a feature would be used.

[Sandy]: Modified the three timers (connect-retry, hold, keepalive) to fixed format.



-“import ietf-yang-types” should have a reference to RFC6991 (see section 4.7 of

rfc6087bis-15)

- “import ietf-inet-types” should have a reference to RFC6991

- “import ietf-routing” should have a reference to RFC8022

- “import ietf-interfaces” should have a reference to RFC7223

- "import ietf-ip" should have a reference to RFC7277

- "import ietf-key-chain" should have a reference to RFC8177

[Sandy]: Added all the references above.



- organization s/"...PIM( Protocols for IP Multicast ) Working

Group"/"...PIM (Protocols for IP Multicast) Working Group"?

- Remove WG Chairs from contact information as per Appendix C of rfc6087bis-15

- No copyright in the module description, see Appendix of 6087bis-15 for a module description

example

- Module description must contain reference to RFC, see Appendix C of

rfc6087bis-15

[Sandy]: Removed WG chairs and add copyright from Appendix of rfc6087bis. Added reference to RFC3618.



- grouping authentication-container. key-chain and password both

use if-feature peer-key-chain.

[Sandy]: Removed the if-feature peer-key-chain from password.



- grouping connect-source. The name is not very

descriptive. Should this be something along the lines of tcp-connection-source?

[Sandy]: Changed the name "connect-source" to "tcp-connection-source".



- grouping global-state-attributes has nothing

[Sandy]: Deleted the grouping.



- Some of the descriptions are

pretty terse. e.g. for rpf-peer it says "RPF peer.". In a case like this

consider adding more descriptive text or a reference to the proper section in

RFC3618

[Sandy]: Added more description.



- peer-as (Autonomous System Number) is defined as type string, should

be of type as-number in ietf-inet-types?

[Sandy]: Modified to inet types.



- keepalive-interval depends on holdtime-interval.

There should be "if-feature peer-timer-holdtime" under leaf keepalive-interval

or change the must statement to (assuming we keep the 2 features):

  must "(not ../holdtime-interval) or (. > 1 and . < ../holdtime-interval)".

[Sandy]: Modified the features to fixed format.



- leaf up-time: s/sa cache/SA cache/

- leaf peer-learned-from, change description from "The address of peer that we learned

this SA from ." to "The address of the peer that we learned this SA from."

[Sandy]: Modified.



- RPC leaf group, I thought we had a type for IP multicast address? If not, it should be done?

[Sandy]: Yes. Added the rt-type reference to RFC8294.



- s/msdp/MSDP/

- In rpc msdp-clear-peer, s/Clears the session to the peer./Clears

the TCP connection to the peer./

- In rpc msdp-clear-sa-cache, why have the enum '*' for source-addr. Can't the same technique as for peer-address be



used?

- msdp prefix not needed in rpc names

[Sandy]: Done.



- MSDP peers are configured in a mesh-group, did the authors consider adding state per mesh-group, e.g. all the

peers in a particular mesh-group?

[Sandy]: IMO it is unnecessary because the states of peers is not unified in a mesh-group.



General:

- Per Appendix B of rfc6087bis-15: "that all YANG modules containing

imported items are cited as normative reference". So RFCs 6991, 7223,

7277, 8022 and 8177 should be included in the normative reference

section.

[Sandy]: Added.



- Section 3 "the irrelevant information", add a reference/explanation for what

the irrelevant information is. s/the irrelevant information/irrelevant

information/?

[Sandy]: Changed the description.



- Section 5 should give a brief description of what the RPCs do.

[Sandy]: Added some description.



- Section 6 any plans for notifications? If not, just say so.

[Sandy]: Done.



- Need Security

Considerations, see sections 3.7 and 6 of rfc6087bis-15

[Sandy]: Added security consideration section.



- Need IANA Considerations, see section 3.8 of rfc6087bis-15

[Sandy]: Added IANA considerations.



- Need license in YANG module,

see appendix B of rfc6087bis-15

[Sandy]: Added the YANG module description.



Thanks,

Sandy