u/kalmukh_net

▲ 5 r/Netbox

How do you model the remote side of B2B site-to-site IPsec tunnels in NetBox?

Hi all,

I'm documenting our site-to-site IPsec tunnels in NetBox (4.6.4). For tunnels between our own devices it works fine: two terminations, each with a device, an interface and an outside IP.

The problem is B2B tunnels to external organizations. The remote gateway isn't ours, we don't manage it and know almost nothing about it except the peer IP. But a tunnel termination has to point to an interface on a device or VM, and the outside IP has to be assigned to that device.

Options I'm considering:

  1. Create the tunnel with only one termination (our side) and put the peer IP and partner name in the description/comments. Simple, but the peer IP is just text, so it isn't searchable as an IP object.

  2. Create a placeholder device per partner (dedicated site, a role like "External VPN peer", a generic device type), add one virtual interface, assign the peer's public IP as a /32, and use it as the second termination. Then tag the device, the IP and the tunnel so it's obvious these aren't real managed devices.

Option 2 looks cleaner to me, but I'm worried about polluting the device inventory with fake devices (device counts, reports, anything that syncs from NetBox to monitoring).

How do you handle this in production?

- Placeholder devices, a single termination, custom fields, something else?

- If you use placeholders, how do you keep them out of monitoring/automation that reads from NetBox?

- Anything you regret about the approach you chose?

Thanks!

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u/kalmukh_net — 9 days ago
▲ 4 r/Netbox

Tunnel Termination: Outside IP dropdown only shows IPs assigned to the tunnel interface. How do you model the underlay (tunnel source) IP?

Hi all,

I'm documenting GRE / GRE-over-IPsec tunnels in NetBox Community v4.6.4-Docker-5.0.1 and I'm stuck on the Outside IP field in the Tunnel Termination form.

**Setup (anonymized)**

Two routers connected over a provider L3VPN, with a GRE tunnel on top:

- Sub-interface `Gi0/0/0.X` has `192.0.2.1/30`. This is the link to the provider and the tunnel source.

- `Tunnel1` has `10.0.0.1/30`. This is the overlay address.

- Config: `tunnel source 192.0.2.1`, `tunnel destination 198.51.100.1`

In NetBox:

- `192.0.2.1/30` is assigned to the `Gi0/0/0.X` interface of Device-A

- `10.0.0.1/30` is assigned to `Tunnel1` of Device-A

**Problem**

When I add a termination to the Tunnel, the Outside IP dropdown only lists the IPs assigned to the tunnel interface (`10.0.0.x`). The tunnel source `192.0.2.1/30` on the sub-interface is not offered, even when I search for it by address.

Assigning the tunnel source IP to the tunnel interface itself would work around it, but that's wrong: the tunnel would then be built on top of its own address, and the underlay/overlay separation is lost.

**What I checked**

- The IP exists in IPAM, is Active, and is assigned to the sub-interface

- No VRF on the address [adjust if needed]

- Refreshed the page, searched by address

**Questions**

  1. Is this filtering intended behavior, or a bug?

  2. How do you model the tunnel source/destination (underlay) addresses for Outside IP?

  3. Is there a workaround (VRF settings, order of filling the form, custom config)?

Thanks in advance, and happy to provide more details (with sensitive data removed).

reddit.com
u/kalmukh_net — 14 days ago