link-local next-hop + interface not possible

[aibix0001]

Sorry for chiming in this late, but I think there is still an error in the logic.
Using this playbook:

---                                                                      
- hosts: tags_isp1                                                       
  connection: ansible.netcommon.network_cli                              
  gather_facts: false                                                    
  vars:                                                                  
    ansible_user: vyos                                                   
    ansible_network_os: vyos.vyos.vyos                                   
  tasks:                                                                 
    - name: Set nex-hop                                                  
      vyos.vyos.vyos_static_routes:                                      
        config:                                                          
          - address_families:                                            
            - afi: ipv6                                                  
              routes:                                                    
                - dest: '2001:aaaa:bbbb:cccc::/56'                        
                  next_hops:                                             
                    - forward_router_address: 'fe80::be24:11ff:fe3f:af6'
                      interface: 'eth2'                                  
        state: rendered                                                  
      register: output                                                   
                                                                         
    - name: Display output                                               
      debug:                                                             
        msg: "{{ output }}"

When I use state: rendered it works correctly:

ok: [p1r4v] => {
    "msg": {
        "changed": false,
        "failed": false,
        "rendered": [
            "set protocols static route6 2001:aaaa:bbbb:cccc::/56",
            "set protocols static route6 2001:aaaa:bbbb:cccc::/56 next-hop 'fe80::be24:11ff:fe3f:af6'",
            "set protocols static route6 2001:aaaa:bbbb:cccc::/56 interface 'eth2'"
        ]
    }
}

but when using state:replaced it fails:

[ERROR]: Task failed: Action failed: 'forward_router_address'
Origin: /home/aibix/projects/ansible-playbooks/playbooks/routes-test.yml:9:7

7     ansible_network_os: vyos.vyos.vyos
8   tasks:
9     - name: Set nex-hop
        ^ column 7

fatal: [p1r4v]: FAILED! => {"changed": false, "msg": "'forward_router_address'"}

The CLI is accepting the config:

vyos@p1r4v:~$ show conf comm | match route6
set protocols static route6 2001:aaaa:bbbb:cccc::/56 next-hop fe80::be24:11ff:fe3f:af6 interface 'eth2'

As it should be (one needs an interface when next-hop is a link-local).

What am I missing? Can this be fixed?

Originally posted by @aibix0001 in #398 (comment)

[omnom62]

Hi @aibix0001

Thank you for following this up - I will review and get to you as soon as I can

[omnom62]

@aibix0001 again - thanks for reporting this!
The original bugfix requested here https://vyos.dev/T6834 read like There are a few issues that make supporting interface routes not possible today: forward_router_address is required, which doesn't make sense for an interface route. For a static route you need one of forward_router_address or interface.
So 'one of ...' is taken literally - and indeed, the module supports setting either (interface was not a valid option before this bugfix).
As such, I believe if we need to support both simultaneously, we need to raise a Bug report

[aibix0001]

@omnom62 thanks for considering this. Maybe, to stay inline with the original request, add a check if next-hop is link-local address when combining next-hop+interface? This way the original argument stays sound and we can have link-local next-hops.

Use case btw: multiple clients on one interface requesting IA_PD. Since VyOS does not install routes for IA_PDs via its relay-agent, one has to take care of this. And in the dhcpv6 relay-message the clients address is the link-local of their WAN.

[omnom62]

@aibix0001 hi!
#444 is the fix

[omnom62]

the fix was implemented a while ago
T ticket is closed
Closing this one too