topic Issue configuring multispeed interfaces via NETCONF in Tools

Issue configuring multispeed interfaces via NETCONF

julienclaerhout — Thu, 10 Jul 2025 12:16:44 GMT

Hi all,

I’m running into an issue when trying to configure multispeed interfaces (10/25/50G) via NETCONF on Catalyst 9600 (C9600-LC-40YL4CD / IOS-XE 17.12).

Context:

I need to configure interfaces like FiftyGigE2/0/10 or TwentyFiveGigE1/1/1 via NETCONF (e.g., no switchport, mtu, channel-group, etc.).
These interfaces do not appear in the XML schema of the device (get-config on /native/interface/... doesn’t return them).
When I attempt to create or modify them (using either Cisco-IOS-XE-native or ietf-interfaces), I get errors like:

inconsistent value: Device refused one or more commands
/if:interfaces/interface[name='FiftyGigE2/0/10']/type is not configured

In CLI, the exact same configuration works perfectly.

Hypothesis:
Could this be because these ports are multigig/multispeed and require the speed to be fixed in order to instantiate the interface in YANG?
(I tried forcing speed in CLI and disabling auto-negotiation, but it didn’t change NETCONF behavior.)
Or is this a known limitation of Cisco-IOS-XE-native YANG models with multispeed linecards?

Already tried:

Creating the interface via ietf-interfaces with <type>ianaift:ethernetCsmacd</type> → same error.
Preconfiguring in CLI (speed 25000, no negotiation auto, no shutdown), then using NETCONF → still rejected.
Searched for relevant bugs or caveats (found CSCwk61990 on FiftyGigE not visible via NETCONF but not sure it applies).

Question:
How can I configure multispeed interfaces via NETCONF?
Is there a required sequence (e.g., activate ports in CLI first, then use NETCONF)?
Or is a newer IOS-XE version required for full YANG support?
Any alternative approaches (different YANG model)?

Thanks in advance for any insights.

Re: Issue configuring multispeed interfaces via NETCONF

bigevilbeard — Thu, 10 Jul 2025 12:26:53 GMT

Digging into very grey matter in my mind here, but think this is a limitation in XE, as (and i am happy to be wrong here) the get-config does not pull these back because they are considered "virtual" or "dormant" state until they're explicitly configured with a specific speed. The YANG models can't see or manipulate interfaces that haven't been "instantiated" with a fixed speed configuration.

I think (guess here) and read this was better in later versions of XE. In the mean time, you could use CLI for initial speed configuration, then NETCONF after?

Re: Issue configuring multispeed interfaces via NETCONF

julienclaerhout — Thu, 10 Jul 2025 13:48:21 GMT

I went ahead and tried your suggestion: I fixed the speed on one of the multispeed interfaces via CLI (speed 25000, speed nonegotiate, no shutdown).

Unfortunately:

The interface still does not appear in the YANG model when doing a get-config.
Attempts to configure it via NETCONF still return same errors

So even after instantiating the interface with a fixed speed, NETCONF does not seem to have visibility or write access to it.

This makes me wonder:
-> Are these multispeed interfaces simply not configurable via NETCONF at all on IOS-XE 17.12 (even after being initialized)?
-> Or is there a workaround (other than falling back to CLI for those ports)?

I’d really prefer to avoid mixing CLI and NETCONF in my playbooks if possible.

Re: Issue configuring multispeed interfaces via NETCONF

bigevilbeard — Thu, 10 Jul 2025 14:51:32 GMT

Thanks for testing this, i would agree this appears to be a platform limitation and hopefully if you upgradee addressed in later release/version.

Re: Issue configuring multispeed interfaces via NETCONF

rogaglia — Tue, 22 Jul 2025 14:46:24 GMT

First, I did not test it in XE but for OpenConfig in XR I tried the following NSO template:

```

<config-template xmlns="http://tail-f.com/ns/config/1.0">

<?set MTU={/mtu}?>

<?foreach {/device}?>

<?foreach {interfaces}?>

<type xmlns:ianaift="urn:ietf:params:xml:ns:yang:iana-if-type">ianaift:ethernetCsmacd</type>

</config>

<hold-time>

</config>

</hold-time>

</interface>

<?end?>

</interfaces>

</config>

</device>

<?end?>

</devices>

</config-template>

```

So, from my experience and looking at the YANG model, the "type" leaf is mandatory but you need to add the correct namespace as it uses a IANA model definition: <type xmlns:ianaift="urn:ietf:params:xml:ns:yang:iana-if-type">ianaift:ethernetCsmacd</type>

Maybe try this encoding for the type.