# Instances Lose External Connectivity After Detaching Floating IP

## Problem

After removing a floating IP from an instance, external connectivity ceases.

## Environment

* Platform9 Managed OpenStack - v4.5 - v5.2
* Neutron

## Cause

The ***neutron-l3-agent*** service fails to update the routing rule corresponding to the instance's fixed IP within the router namespace on the L3 agent node(s) responsible for hosting the virtual router (in a DVR configuration, this would be the instance hypervisor). Subsequently, this causes a loss of external connectivity for the instance.

## Resolution

1. Identify the fixed IP, network, and host associated with the affected instance.

<figure><img src="/files/Pay94RobMjrrdMmTZIqe" alt="Screen_Shot_2020-01-02_at_3.38.20_PM.png"><figcaption><p>Screen_Shot_2020-01-02_at_3.38.20_PM.png</p></figcaption></figure>

2. Identify the router associated with the network.

<figure><img src="/files/XEB9JoRp4pznacuQfCX7" alt="Screen_Shot_2020-01-02_at_3.39.56_PM.png"><figcaption><p>Screen_Shot_2020-01-02_at_3.39.56_PM.png</p></figcaption></figure>

3. Record the UUID of the network and router identified in the previous two steps.

{% hint style="info" %}
**Info**

**Note**: In the UI, this may be done by navigating to the "Networks" tab, selecting either Networks or Routers and then subsequently clicking on the name of the resource. An **OpenStack UUID** column will be visible in the resource overview.
{% endhint %}

4. In the **`qrouter`** namespace (corresponding to the UUID of the router) on the instance's host, inspect the routing rules.

{% hint style="warning" %}
**Attention**

**Note**: In the following examples, a unique router UUID will be used which will differ from your own. Ensure you replace the UUID when executing the commands yourself.
{% endhint %}

{% tabs %}
{% tab title="None" %}

```none
# ip net e qrouter-204830ee-4553-4c25-b720-646e565ee4bf ip rule
0: from all lookup local
32766: from all lookup main
32767: from all lookup default
66502: from 192.168.0.28 lookup 16
3232235521: from 192.168.0.1/24 lookup 3232235521
```

{% endtab %}
{% endtabs %}

5. Inspect the route table (of which the ID may be identified based on the prior step) corresponding to the instance's fixed IP.

{% tabs %}
{% tab title="None" %}

```none
# ip net e qrouter-204830ee-4553-4c25-b720-646e565ee4bf ip route show table 16
default via 169.254.110.93 dev rfp-c0dd3bdd-3
```

{% endtab %}
{% endtabs %}

The default route with the `rfp` interface in the rule indicates all instance traffic is still going to the floating IP namespace.

6. Delete the stale routing rule.

{% tabs %}
{% tab title="None" %}

```none
# ip net e qrouter-204830ee-4553-4c25-b720-646e565ee4bf ip rule del pref 66502
```

{% endtab %}
{% endtabs %}

## Additional Information

* [LP #1891673 – qrouter ns ip rules not deleted when fip removed from vm](https://bugs.launchpad.net/neutron/+bug/1891673)


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