Layer-2 GRE Tunnels
Layer-2 GREGeneric Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. tunnels allow you to have the same VLANVirtual Local Area Network. In computer networking, a single Layer 2 network may be partitioned to create multiple distinct broadcast domains, which are mutually isolated so that packets can only pass between them through one or more routers; such a domain is referred to as a Virtual Local Area Network, Virtual LAN, or VLAN. in multiple locations (separated by a Layer-3 network) and be connected. The forwarding method for a Layer-2 GREGeneric Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. tunnel is bridging.
However, the drawback of using Layer-2 GREGeneric Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. tunnels is that all broadcasts are flooded through the tunnel, adding traffic load to the network and the managed devices. Starting from ArubaOS 8.4.0.0, both trusted and untrusted VLANsVirtual Local Area Network. In computer networking, a single Layer 2 network may be partitioned to create multiple distinct broadcast domains, which are mutually isolated so that packets can only pass between them through one or more routers; such a domain is referred to as a Virtual Local Area Network, Virtual LAN, or VLAN. are supported on a single Layer-2 GREGeneric Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. tunnel.
The traffic flow illustrated by Figure 1 is as follows:
1. The frame enters the source managed device (Controller-1) on VLANVirtual Local Area Network. In computer networking, a single Layer 2 network may be partitioned to create multiple distinct broadcast domains, which are mutually isolated so that packets can only pass between them through one or more routers; such a domain is referred to as a Virtual Local Area Network, Virtual LAN, or VLAN. 101.
The frame is bridged through Controller-1 into the Layer-2 GREGeneric Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. tunnel.
2. The frame is encapsulated in a GREGeneric Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. packet.
3. The GREGeneric Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. packet enters the network on VLANVirtual Local Area Network. In computer networking, a single Layer 2 network may be partitioned to create multiple distinct broadcast domains, which are mutually isolated so that packets can only pass between them through one or more routers; such a domain is referred to as a Virtual Local Area Network, Virtual LAN, or VLAN. 10, is routed across the network to the destination managed device (Controller-2), and then exits the network on VLANVirtual Local Area Network. In computer networking, a single Layer 2 network may be partitioned to create multiple distinct broadcast domains, which are mutually isolated so that packets can only pass between them through one or more routers; such a domain is referred to as a Virtual Local Area Network, Virtual LAN, or VLAN. 20.
The source IP address of the GREGeneric Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. packet is the IP address of the interface in VLANVirtual Local Area Network. In computer networking, a single Layer 2 network may be partitioned to create multiple distinct broadcast domains, which are mutually isolated so that packets can only pass between them through one or more routers; such a domain is referred to as a Virtual Local Area Network, Virtual LAN, or VLAN. 10 in Controller 1.
4. The frame is de-encapsulated and bridged out of the destination managed device (Controller-2) on VLANVirtual Local Area Network. In computer networking, a single Layer 2 network may be partitioned to create multiple distinct broadcast domains, which are mutually isolated so that packets can only pass between them through one or more routers; such a domain is referred to as a Virtual Local Area Network, Virtual LAN, or VLAN. 101.
Configure a Layer-2 GREGeneric Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. tunnel using the WebUI or CLICommand-Line Interface. A console interface with a command line shell that allows users to execute text input as commands and convert these commands to appropriate functions..
Configuring a Layer-2 GRE Tunnel in the WebUI
To configure a Layer-2 GREGeneric Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. tunnel for a source managed device and destination managed device via the WebUI:
1. In the node hierarchy, navigate to > > .
2. Create a new GREGeneric Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. tunnel by clicking below the table, or edit an existing GREGeneric Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. tunnel by selecting an entry from the table.
3. Enter the corresponding GREGeneric Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. tunnel values for this managed device.
4. (Optional) Select the checkbox to enable tunnel keepaliveSignal sent at periodic intervals from one device to another to verify that the link between the two devices is working. If no reply is received, data will be sent by a different path until the link is restored. A keepalive can also be used to indicate that the connection should be preserved so that the receiving device does not consider it timed out and drop it. heartbeats. For more information on this feature, see GRE Tunnels
5. Click .
6. Click .
7. In the window, select the check box and click .
8. Next, access the destination managed device and navigate to > > .
9. Select the tunnel ID of interest from the table.
10. Use the edit screen to configure the destination managed device.
11. (Optional) Select the checkbox to enable tunnel keepaliveSignal sent at periodic intervals from one device to another to verify that the link between the two devices is working. If no reply is received, data will be sent by a different path until the link is restored. A keepalive can also be used to indicate that the connection should be preserved so that the receiving device does not consider it timed out and drop it. heartbeats.
12. Click .
13. Click .
14. In the window, select the check box and click .
Configuring a Layer-2 GRE Tunnel in the CLI
Referring to Figure 1, the following are the required configurations to create the Layer-2 GREGeneric Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. tunnel between controllers named Controller-1 and Controller-2:
(host) [mynode] (config) # interface tunnel 101
description “IPv4 Layer-2 GRE 101"
tunnel mode gre 1
tunnel source vlan 101
tunnel destination 192.168.1.1
tunnel keepalive
trusted
tunnel vlan 101
trusted vlan 101
(host) [mynode] (config) # interface tunnel 201
description “IPv4 Layer-2 GRE 201"
tunnel mode gre 1
tunnel source vlan 201
tunnel destination 192.168.2.1
tunnel keepalive
trusted
tunnel vlan 201
trusted vlan 201
The following command example configures a Layer-2 GREGeneric Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. tunnel for IPv6:
(host) [mynode] (config) # interface tunnel 301
description “IPv6 Layer-2 GRE 301"
tunnel mode gre 1
tunnel source ipv6 vlan 301
tunel destination ipv6 2001:1:2:2020::1
tunnel keepalive
trusted
tunnel vlan 301
trusted vlan 301
(host) [mynode] (config) # interface tunnel 401
description “IPv6 Layer-2 GRE 401"
tunnel mode gre 2
tunnel source ipv6 vlan 401
tunnel destination ipv6 2001:1:2:1010::1
tunnel keepalive
trusted
tunnel vlan 401
trusted vlan 401
Was this information helpful?
Great! Thanks for the feedback
Sorry about that! How can we improve it? Send your comments and suggestions!