Layer-3 GRE Tunnels
The benefit of Layer-3 GRE Generic Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. tunnels is that broadcasts are not flooded through the tunnel, so there is less wasted bandwidth and less load on the managed devices. The forwarding method for a Layer-3 GRE Generic Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. tunnel is routing. By default, GRE Generic Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. tunnels are in IPv4 Layer-3 mode.
Figure 1 IPv4 Layer-3 GRE Tunnel
Figure 2 IPv6 Layer-3 GRE Tunnel
IPv6 encapsulated in IPv4 and IPv4 encapsulated in IPv6 are not supported. The only Layer-3 GRE Generic Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. modes supported are IPv4 encapsulated in IPv4 and IPv6 encapsulated in IPv6.
The following sections describe:
Layer-3 Tunnel Traffic Flow
The traffic flow illustrated by and is as follows:
- The frame enters the source managed device (Controller-1) on VLAN Virtual 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 IP packet within the frame is routed through Controller-1 into the Layer-3 GRE Generic Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. tunnel.
- The IP packet is encapsulated in a GRE Generic Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. packet.
- The GRE Generic Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. packet enters the network on VLAN Virtual 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 destination managed device (Controller-2), and then exits the network on VLAN Virtual 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 GRE Generic 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 VLAN Virtual 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.
- The IP packet is de-encapsulated and routed out of the destination managed device (Controller-2) on VLAN Virtual 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. 202.
Limitations for Static IPv6 Layer-3 Tunnels
ArubaOS does not support the following functions for static IPv6 Layer-3 GRE Generic Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. tunnels:
- IPv6 Auto-configuration and IPv6 Neighbor Discovery mechanisms do not apply to IPv6 GRE Generic Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. tunnels.
- The tunnel encapsulation limit and MTU Maximum Transmission Unit. MTU is the largest size packet or frame specified in octets (eight-bit bytes) that can be sent in networks such as the Internet. discovery options are not supported on IPv6 GRE Generic Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. tunnels.
The following procedure configures an IPv4 Layer-3 GRE Generic Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. tunnel for Controller-1 and Controller-2:
- In the source node hierarchy, select Controller-1
- Navigate to > > . The page is displayed.
- Create a new GRE Generic Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. tunnel by clicking + below the GRE Generic Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. Tunnel table, or edit an existing GRE Generic Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. tunnel by selecting that entry in the GRE Generic Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. Tunnel table. The configuration options appear.
- Click the IP Version drop-down list and select IPv4 or IPv6.
- Enter the corresponding GRE Generic Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. tunnel values for the controller.
- To configure an IPv4 GRE Generic Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. tunnel , use values for Controller-1 based on the network shown in .
- To configure an IPv6 GRE Generic Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. tunnel , use values for Controller-1 based on the network shown in .
If a VLAN Virtual 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. interface has IPv6 addresses configured, one of them is used as the tunnel source IPv6 address. If the selected IPv6 address is deleted from the VLAN Virtual 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. interface, then the tunnel source IP address is reconfigured with the next available IPv6 address.
- (Optional for IPv4 or IPv6 GRE Generic Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. Tunnels) Select to enable tunnel keepalive Signal 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 Layer-3 GRE Tunnels
- Click .
- Click .
- In the window, select the check box and click
- Next, log into Controller-2 and navigate to
- Create a new GRE Generic Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. tunnel by clicking + below the GRE Generic Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. Tunnel table, or edit an existing GRE Generic Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. tunnel by selecting that entry in the GRE Generic Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. Tunnel table. The configuration options appear.
- Enter the corresponding GRE Generic Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. tunnel values for this controller.
- To create an IPv4 L3 GRE Generic Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. tunnel, use the values for Controller-2 as shown in .
- To create an IPv6 L3 GRE Generic Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. tunnel, use the values for Controller-2 as shown in .
- (Optional for IPv4 or IPv6 GRE Generic Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. Tunnels) Select to enable tunnel keepalive Signal 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.
- Click .
- Click .
- In the window, select the check box and click .
The following CLI Command-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. command examples configure an IPv4 Layer-3 GRE Generic Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. tunnel for IPv4 between two controllers:
Referring to , the following are the required configurations to create the IPv4 Layer-3 GRE Generic 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 104
description “IPv4 L3 GRE 104"
trusted
tunnel
mode gre ip
ip address 1.1.1.1 255.255.255.255
source vlan 10
destination 20.20.20.249
(host) [mynode] (config) # interface tunnel 204
description “IPv4 L3 GRE 204"
trusted
tunnel
mode gre ip
ip address 1.1.1.2 255.255.255.255
source vlan 20
destination 10.10.10.249
The following command example configures a Layer-3 GRE Generic 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 106
description “IPv6 Layer-3 GRE 106"
trusted
tunnel
tunnel mode gre ipv6
ipv6 address 2001:1:2:1::1
tunnel source ipv6 vlan 10
tunnel destination ipv6 2001:1:2:2020::1
(host) [mynode] (config) # interface tunnel 206
description “IPv6 Layer-3 GRE 206"
trusted
tunnel
tunnel mode gre ipv6
ipv6 address 2001:1:2:1::2
tunnel source ipv6 vlan 20
tunnel destination ipv6 2001:1:2:1010::1