How to Configure GRE Tunnels for the Branch Site

The Virtual WAN LAN GRE Tunnels settings enable you to configure Virtual WAN Appliances to terminate GRE tunnels on the LAN. If you do not want to configure this branch site as a LAN GRE Tunnel termination node, you can skip this step, and proceed to the section, Configuring the WAN Links for the Branch Site.

To configure a LAN GRE Tunnel for the branch site, do the following:

  1. Continuing in the site tree for the new branch site, click + to the left of the LAN GRE Tunnels branch label.

    This opens the LAN GRE Tunnels table for the new site.

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  2. Click + to the right of the LAN GRE Tunnels.

    This adds a new blank LAN GRE Tunnel entry to the table and opens it for editing.

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  3. Configure the LAN GRE Tunnel settings.

    Enter the following:

    • Name – Enter a name for the new LAN GRE tunnel, or accept the default. The default uses the following naming format:


      Where <number> is the number of LAN GRE Tunnels configured for this site, incremented by one.

    • Source IP – Select a Source IP Address for the tunnel from the drop-down menu for this field. The menu options will be the list of Virtual IP Addresses that you configured for this site. You must configure at least one Virtual Interface and one Virtual IP Address before you can configure a LAN GRE Tunnel. For instructions, see the sections, Configuring the Virtual Interface Groups for the Branch Site and Configuring the Virtual IP Addresses for the Branch Site.

    • Destination IP – Enter the destination IP Address for the tunnel.

    • Tunnel IP / Prefix  – Enter the tunnel IP Address and prefix.

    • Checksum  – Select this to enable Checksum for the tunnel GRE header.

    • Keepalive Period(s) – Enter the wait time interval (in seconds) between keepalive messages. If configured to 0, no keepalive packets will be sent, but the tunnel will remain up. The default is 10.

    • Keepalive Retries  – Enter the number of keepalive retries the Virtual WAN Appliance should attempt before it brings down the tunnel. The default is 3.

  4. Click Apply.

    This submits your settings and adds the new LAN GRE Tunnel entry to the table.

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  5. To configure additional LAN GRE Tunnels, click + to the right of the LAN GRE Tunnels branch label, and proceed as above.

    The next step is to configure the WAN links for the branch site.

How to Configure GRE Tunnels for the Branch Site