I find `elif` statements confusing because they have a explicit condition (the one after "elif ") and an implicit condition (the logical inverse of the preceding `if` statement). I figured it was easier to understand when more permissive options *override* less permissive ones, because the logic is more repetitive (to me) easier to follow. Were you thinking of something like this?

```python
        if str(ipaddr.IPv4Address(start)) in allow_all_subnets:
            allow = ALLOW_ANY
        elif known:
            allow = ALLOW_KNOWN
        elif '128.193.177.71' == str(ipaddr.IPv4Address(start)):
            allow = ALLOW_VRF_AND_LEGACY
            v, _ = Vrf.objects.get_or_create(name="ip-phones-hack")
            n.vrf = v
            n.save()
        elif '128.193.166.81' == str(ipaddr.IPv4Address(start)):
            allow = ALLOW_VRF_AND_LEGACY
            v, _ = Vrf.objects.get_or_create(name="avaya-hack")
            n.vrf = v
            n.save()
```