Bug introduced in: 201e92a3

Bug introduced in: d2d33c90

Bug introduced in: d2d33c90

- Allow for setting up multiple routes.
- Remove hardcoded lizard subnet from tinc-up template.
- Replace `route` for `ip route`.

Bug introduced in: 7ad038cf

Currently:

- All monitoring is performed through the VPN.
- Lizard is the single entrypoint to the VPN.
- When lizard is down, monitoring doesn't work.

Because we're introducing a new server (Iguana) in our infra and we want
monitoring of the new server to work even when/if Lizard is down, we
need to allow multiple entrypoints to the VPN.

See the message in tails-l10n:

    Message-ID: <8fe9a4a1-cb8a-b2b0-6dd6-2e926e40dccb@renaudineau.org>
    From: Chre <tor@renaudineau.org>
    Subject: [Tails-l10n] Ask for new french reviewer
    To: Tails localization discussion <tails-l10n@boum.org>
    Date: Wed, 30 Jun 2021 20:52:50 +0200

refs tails#18385