lag module should model peerlink as regular VLAN

[jbemmel]

Most MLAG platforms support things like OSPF on the peerlink between the MLAG router pair; the lag module should create a subinterface as appropriate, and allow these modules to do their job

For example, this should work as expected:

module: [ ospf, lag, vlan ]

links:
- lag:
    members: [ s1, s2 ]
    mlag.peergroup: True

Likewise:

module: [ ospf, lag, vlan ]

links:
- lag:
    members: [ s1, s2 ]
    mlag.peergroup: True
  ospf: False

[ipspace]

As most platforms want to have some sort of VLANs on the peer link, what's stopping you from using a routed VLAN to run OSPF on it?

[jbemmel]

With the benefit of hindsight, I'm now realizing that the way the lag templates are structured is sub-optimal. They replicate some of the logic for provisioning a custom VLAN and allocating IPs, instead of relying on the VLAN module to do that part. The latter has the benefit that other features - such as OSPF configs - can be applied too.

There is nothing "stopping" me, but I wanted to add OSPF support and I'm now thinking that's better done through refactoring (as opposed to adding OSPF config to the lag templates)