Comment 2 for bug 1761838

Hi John,

I didn't specifically took any action w.r.t. setting up Fan, it came for free. Even more, when bootstrapping a new GCE controller, I set model-defaults of fan-config="" and container-networking-method=local. However, to my surprise, these defaults always got ignored when adding a new model. Specifically setting the configs during model creation did the trick, but there we have another problem. I need to be able to do this from libjuju and as it looks like it, I cannot set empty configs during model creation. So back to square 0, but that's something for another feature request. Long story short, it looks like Fan comes all automatically.

For now I rather have it not set on my system, since I'm not planning to use LXD containers in these deployments. But I guess this is behavior not specific to the charms I use and at some point people (me included) will want to try Fan and have the correct info when requesting the private IP address.

Here's some output from ip commands:
```
ubuntu@juju-ae73d8-0:~$ ip -all address
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: ens4: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1460 qdisc mq state UP group default qlen 1000
    link/ether 42:01:0a:84:00:02 brd ff:ff:ff:ff:ff:ff
    inet 10.132.0.2/32 brd 10.132.0.2 scope global ens4
       valid_lft forever preferred_lft forever
    inet6 fe80::4001:aff:fe84:2/64 scope link
       valid_lft forever preferred_lft forever
3: lxdbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000
    link/ether fe:01:27:c3:1d:33 brd ff:ff:ff:ff:ff:ff
    inet6 fe80::fc01:27ff:fec3:1d33/64 scope link
       valid_lft forever preferred_lft forever
    inet6 fe80::1/64 scope link
       valid_lft forever preferred_lft forever
4: fan-252: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1410 qdisc noqueue state UP group default qlen 1000
    link/ether 0e:f2:97:86:25:aa brd ff:ff:ff:ff:ff:ff
    inet 252.0.32.1/8 scope global fan-252
       valid_lft forever preferred_lft forever
    inet6 fe80::cf2:97ff:fe86:25aa/64 scope link
       valid_lft forever preferred_lft forever
5: ftun0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1410 qdisc noqueue master fan-252 state UNKNOWN group default qlen 1000
    link/ether 0e:f2:97:86:25:aa brd ff:ff:ff:ff:ff:ff
    inet6 fe80::cf2:97ff:fe86:25aa/64 scope link
       valid_lft forever preferred_lft forever
ubuntu@juju-ae73d8-0:~$ ip -all route
default via 10.132.0.1 dev ens4
10.132.0.1 dev ens4 scope link
252.0.0.0/8 dev fan-252 proto kernel scope link src 252.0.32.1
```

And from ifconfig, to be complete:
```
ubuntu@juju-ae73d8-0:~$ ifconfig
ens4 Link encap:Ethernet HWaddr 42:01:0a:84:00:02
          inet addr:10.132.0.2 Bcast:10.132.0.2 Mask:255.255.255.255
          inet6 addr: fe80::4001:aff:fe84:2/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST MTU:1460 Metric:1
          RX packets:322544 errors:0 dropped:0 overruns:0 frame:0
          TX packets:307338 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:256913017 (256.9 MB) TX bytes:35581372 (35.5 MB)

fan-252 Link encap:Ethernet HWaddr 0e:f2:97:86:25:aa
          inet addr:252.0.32.1 Bcast:0.0.0.0 Mask:255.0.0.0
          inet6 addr: fe80::cf2:97ff:fe86:25aa/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST MTU:1410 Metric:1
          RX packets:151259 errors:0 dropped:0 overruns:0 frame:0
          TX packets:151385 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:8976859 (8.9 MB) TX bytes:8960707 (8.9 MB)

ftun0 Link encap:Ethernet HWaddr 0e:f2:97:86:25:aa
          inet6 addr: fe80::cf2:97ff:fe86:25aa/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST MTU:1410 Metric:1
          RX packets:151353 errors:0 dropped:0 overruns:0 frame:0
          TX packets:151374 errors:0 dropped:20 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:8981747 (8.9 MB) TX bytes:6840565 (6.8 MB)

lo Link encap:Local Loopback
          inet addr:127.0.0.1 Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING MTU:65536 Metric:1
          RX packets:8 errors:0 dropped:0 overruns:0 frame:0
          TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:400 (400.0 B) TX bytes:400 (400.0 B)

lxdbr0 Link encap:Ethernet HWaddr fe:01:27:c3:1d:33
          inet6 addr: fe80::1/64 Scope:Link
          inet6 addr: fe80::fc01:27ff:fec3:1d33/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:6 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 B) TX bytes:540 (540.0 B)
```

Hope this helps,
Gregory