---
lastproofread: '2026-03-13'
---

(vpp-config-interfaces-gre)=

```{include} /_include/need_improvement.txt
```


# VPP GRE Configuration

VPP GRE interfaces provide Generic Routing Encapsulation tunneling with
high-performance packet processing. GRE tunnels encapsulate various
protocols within IP packets, enabling connectivity across Layer 3
networks while maintaining the performance benefits of VPP's optimized
data plane.

## Basic Configuration

### Creating a GRE Interface

```{cfgcmd} set interfaces vpp gre \<vppgreN\>

Create a GRE interface where ``<vppgreN>`` follows the naming convention
``vppgre1``, ``vppgre2``, etc.
```

```{cfgcmd} set interfaces vpp gre \<vppgreN\> remote \<address\>

Set the tunnel remote endpoint address. Supports both IPv4 and IPv6
addresses.
```

```{cfgcmd} set interfaces vpp gre \<vppgreN\> source-address \<address\>

Set the tunnel source address. Must match an address configured on
the local system.
```

**Basic Example:**

```none
set interfaces vpp gre vppgre1
set interfaces vpp gre vppgre1 remote 203.0.113.2
set interfaces vpp gre vppgre1 source-address 192.168.1.1
```

## Interface Configuration
### Description and Administrative Control

```{cfgcmd} set interfaces vpp gre \<vppgreN\> description \<description\>

Set a descriptive name for the GRE interface.
```

```{cfgcmd} set interfaces vpp gre \<vppgreN\> disable

Administratively disable the GRE interface.
```

### Tunnel Type

```{cfgcmd} set interfaces vpp gre \<vppgreN\> tunnel-type \<type\>

Set the GRE tunnel encapsulation type:
* ``l3`` - Generic Routing Encapsulation for network layer traffic (default).
* ``teb`` - Transparent Ethernet Bridge for Layer 2 frame transport.
* ``erspan`` - Encapsulated Remote Switched Port Analyzer for traffic
mirroring.
```

### Kernel Interface Integration

LCP kernel pair interface bound to the VPP GRE interface is created
automatically. This allows standard Linux networking tools and
services to interact with the VPP GRE.

## IP Address Configuration

```{cfgcmd} set interfaces vpp gre \<vppgreN\> address \<ip-address/prefix\>

Configure IPv4 or IPv6 addresses on the kernel interface. Multiple
addresses can be assigned.
```

**Examples:**

```none
# IPv4 address
set interfaces vpp gre vppgre0 address 192.168.1.10/24

# IPv6 address
set interfaces vpp gre vppgre0 address 2001:db8::10/64
```

## MTU Configuration

```{cfgcmd} set interfaces vpp gre \<vppgreN\> mtu \<size\>

Set the Maximum Transmission Unit (MTU) for the kernel interface.
The MTU must be compatible with the connected VPP interface.
```

**Example:**

```none
set interfaces vpp gre vppgre0 mtu 9000
```
:::{note}
The MTU size must not exceed the MTU size
supported by the associated VPP interface.
:::

## Configuration Examples

### Layer 3 GRE Tunnel

```none
# IPv4 GRE tunnel
set interfaces vpp gre vppgre1
set interfaces vpp gre vppgre1 description "Site-to-site tunnel"
set interfaces vpp gre vppgre1 remote 203.0.113.10
set interfaces vpp gre vppgre1 source-address 192.168.1.1
set interfaces vpp gre vppgre1 tunnel-type l3
```

### Layer 2 GRE Tunnel (TEB)

```none
# Transparent Ethernet Bridge
set interfaces vpp gre vppgre2
set interfaces vpp gre vppgre2 description "L2 extension tunnel"
set interfaces vpp gre vppgre2 remote 203.0.113.20
set interfaces vpp gre vppgre2 source-address 192.168.1.1
set interfaces vpp gre vppgre2 tunnel-type teb
```

### IPv6 GRE Tunnel

```none
# IPv6 endpoints
set interfaces vpp gre vppgre3
set interfaces vpp gre vppgre3 remote 2001:db8::2
set interfaces vpp gre vppgre3 source-address 2001:db8::1
```

### GRE with Kernel Interface

```none
# GRE tunnel with management interface
set interfaces vpp gre vppgre4
set interfaces vpp gre vppgre4 remote 203.0.113.30
set interfaces vpp gre vppgre4 source-address 192.168.1.1
set interfaces vpp gre vppgre4 address 10.0.1.1/30
```

## Bridge Integration

GRE interfaces can be added as members to VPP bridges for Layer 2
switching. See {doc}`bridge` for detailed bridge configuration.

```none
# Add TEB GRE tunnel to bridge
set interfaces vpp bridge vppbr1
set interfaces vpp bridge vppbr1 member interface vppgre2
set interfaces vpp bridge vppbr1 member interface eth1
```