BelAir20E User Guide
Using Layer 2 Tunnels
April 2, 2012
Confidential
Document Number BDTM02201-A01 Standard
Configuring Tunnels for
a Router using GRE
/protocol/te-<eng>/set tunnel-gre <index (1-5)>
ip <ip_addr> [proxy-arp {all | list | dhcp}]
/protocol/te-<eng>/set tunnel-gre <index (1-5)>
arp-list <IP_addr> [<IP_addr>]
[<IP_addr>] [<IP_addr>]
[<IP_addr>]
/protocol/te-<eng>/set gre autoconfig ip <IP_addr>
interval <seconds> [port <TCP_port>]
These commands are used to create tunnel to the central router using
IP-over-GRE encapsulation instead of L2TP.
Use the
set tunnel-gre ip
command to create GRE tunnels to the specific
destination. GRE tunnels may co-exist with regular L2TP tunnels and L2VPN
tunnels on the same BelAir unit. The
ip
parameter specifies the IP address of
the head end tunnel endpoint. It is usually the IP address of the router
terminating GRE tunnels.
This type of configuration uses proxy ARP because it cannot act as a router to
terminate IP traffic. The
proxy-arp
parameter defines the scope of the proxy
ARP functionality:
• Use
all
if you want to answer ARP requests for any destination IP address.
• Use
dhcp
if you want to answer ARP requests for the default gateway IP
address only. In this case, the gateway IP address is learned from the DHCP
relay communication to the client.
• Use
list
to apply proxy ARP only to traffic destined to a particular set of IP
address. Use the
set tunnel-gre arp-list
command to specify the set of IP
addresses.
The default value of the
proxy-arp
parameter is
all
.
Use the
set gre autoconfig
command to define parameters to communicate to
the third-party heartbeat server using a proprietary protocol. The
ip
parameter
defines the IP address of heartbeat server.
In this configuration, the BelAir20E sends a pseudo heartbeat packet at the
interval specified by the
interval
parameter. The
<seconds>
parameter should
be at least 60 seconds. The default value is 60 seconds. The heartbeat server
uses the pseudo heartbeat packet to determine whether the tunnel’s
operational state is up or down. The heartbeat server also uses the pseudo
heartbeat packet to determine the BelAir20E’s tunnel configuration and correct
it if required.
The optional
port
parameter specifies the TCP port to communicate with the
heartbeat server. The default value is 4040.