B&B Electronics, Inc.
SPECTRE Configuration Manual
23
710-10001-02 Rev. 3.0
www.bb-elec.com
www.bb-europe.com
1.9. VRRP configuration
Select the
VRRP
menu item to enter the VRRP configuration. VRRP protocol (Virtual
Router Redundancy Protocol) allows you to transfer packet routing from the main router to a
backup router in case the main router fails. This can be used to provide a wireless cellular
backup to a primary wired router in critical application. If the
Enable VRRP
is checked, you may
set the following parameters.
Item
Description
Virtual Server
IP Address
This parameter
sets the virtual server IP address. This address must be
the same for both the primary and backup routers. Devices on the LAN
will use this address as their default gateway IP address.
Virtual Server
ID
This parameter distinguishes one virtual router on the network from
another. The main and backup routers must use the same value for this
parameter.
Host Priority
The active router with highest priority set by the parameter
Host Priority
, is
the main router. According to RFC 2338, the main router should have the
highest possible priority - 255. The backup router(s) have a priority in the
range 1
– 254 (default value is 100). A priority value of 0 is not allowed.
Table 12: VRRP configuration
You may set the
Check PPP connection
flag
in the second part of the window to enable
automatic test messages for the cellular network. In some cases, the PPP connection could still
be active but the router will not be able to send data over the cellular network. This feature is
used to verify that data can be sent over the PPP connection and supplements the normal VRRP
message handling. The currently active router (main/backup) will send test messages to the
defined
Ping IP Address
at periodic time intervals (
Ping Interval
)
and wait for a reply (
Ping
Timeout
)
. If the router does not receive a response to the Ping command, it will retry up to the
number of times specified by the
Ping Probes
parameter. After that time, it will switch itself to a
backup router until the PPP connection is restored.
Item
Description
Ping IP Address Destination IP address for the Ping commands.
Ping Interval
Interval in seconds between the outgoing Pings.
Ping Timeout
Time in seconds to wait for a response to the Ping.
Ping Probes
Maximum number of failed ping requests
Table 13: Check PPP connection
You may use the DNS server of the mobile carrier as the destination IP address for the
test messages (Pings).
The
Enable traffic monitoring
option can be used to reduce the number of messages
that are sent to test the PPP connection. When this parameter is set, the router will monitor the
interface for any packets different from a ping. If a response to the packet is received within the
timeout specified by the
Ping Timeout
parameter, then the router knows that the connection is
still active. If the router does not receive a response within the timeout period, it will attempt to
test the PPP connection using standard Ping commands.
