1.1 OPT_UCARP

UCARP is a free Userland-Port of the Common Adress Redundancy Protocols (CARP). CARP was developed by the OpenBSD-Team.

To use UCARP you need at least two systems. Those systems both get a unique IP address. A virtual IP address is defined in addition. One of these systems will become master and the other(s) slaves. The master gets assigned the virtual IP address. If the master goes down, one of the slaves becomes master. The virtual IP address is used as the network gateway.

UCARP instances on fli4l are started by an IP-Up script and stopped by an IP-Down script. This will handle both failure of the router and failure of the Internet connection.

1.1.1 Configuration

OPT_UCARP

'yes' aktivates the package.

UCARP_N

Number of UCARP instances.

UCARP_x_INTERFACE

The interface the UCARP instances should be bound to (i.e. eth0, br0, eth0.7).

UCARP_x_SRCIP

The real IP address and the netmask in CIDR (Classless Inter-Domain Routing) notation set for the UCARP_x_INTERFACE (i.e. 192.168.6.1/24)

UCARP_x_ADDR

The virtual IP address and netmask in CIDR (Classless Inter-Domain Routing) notation (i.e. 192.168.6.10/24)

UCARP_x_PASS

The encrypting password for this UCARP instance.

UCARP_x_PREEMPT

This setting is optional and may be omitted. By specifiying 'yes' the router will become master as fast as possible.

UCARP_x_ADVSKEW

This setting is optional and may be omitted. By this setting the master may be set. The higher the value the lower is its seine right to take role of a master host. Valid values are 0 to 254. The default is 0.