What determines the NETCONF Capabilities of a Device? (IOS-XE)

RAW1456 · ‎11-05-2020

Greetings,

I haven't been able to find out what actually determines the NETCONF Capabilities of a device (In my case an ISR4321).

What do they depend on? Is it the version of IOS-XE they are running? Can Capabilities be added or removed without changing the OS version?

Thank you.

anumishr · ‎11-05-2020

 The capability is identified by a
   uniform resource identifier (URI) [RFC3986].
refer https://tools.ietf.org/html/rfc6241#:~:text=A%20NETCONF%20capability%20is%20a,the%20content%20allowed%20inside%20operations.

Also refer: https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/prog/configuration/171/b_171_programmability_cg/configuring_yang_datamodel.html#id_78218

I tested on a isr4k using following command:

ssh -s admin@<ipaddress> -p 830 netconf

<?xml version="1.0" encoding="UTF-8"?>
<hello xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<capabilities>
<capability>urn:ietf:params:netconf:base:1.0</capability>
<capability>urn:ietf:params:netconf:base:1.1</capability>
<capability>urn:ietf:params:netconf:capability:writable-running:1.0</capability>
<capability>urn:ietf:params:netconf:capability:rollback-on-error:1.0</capability>
<capability>urn:ietf:params:netconf:capability:validate:1.0</capability>
<capability>urn:ietf:params:netconf:capability:validate:1.1</capability>
<capability>urn:ietf:params:netconf:capability:xpath:1.0</capability>

It returns the capability list similar to above. It doesn't really work on older releases so you are right, it would be IOS-XE version dependent. You can check the release notes to find out where the support started.

On ISR4k, it would be supported from release 16.9.1 onwards as I can check.