Setup guide

• Package Management
• IP Addresses and ARP
Description
Virtual Router Redundancy Protocol is an election protocol that provides high availability for
routers. A number of routers may participate in one or more virtual routers. One or more IP
addresses may be assigned to a virtual router. A node of a virtual router can be in one of the
following states:
• MASTER state, when the node answers all the requests to the instance's IP addresses. There
may only be one MASTER node in a virtual router. This node sends VRRP advertisement
packets to all the backup routers (using multicast address) every once in a while (set in
interval property).
• BACKUP state, when the VRRP router monitors the availability and state of the Master
Router. It does not answer any requests to the instance's IP addresses. Should master become
unavailable (if at least three sequential VRRP packets are lost), election process happens, and
new master is proclaimed based on its priority. For more details on virtual routers, see
RFC2338.
VRRP Routers
ip vrrp
Description
A number of VRRP routers may form a virtual router. The maximal number of clusters on one
network is 255 each having a unique VRID (Virtual Router ID). Each router participating in a
VRRP cluster must have it priority set to a valid value.
Property Description
name (name) - assigned name of the VRRP instance
interface (name) - interface name the instance is running on
vrid (integer: 0..255; default: 1) - Virtual Router Identifier (must be unique on one interface)
priority (integer: 1..255; default: 100) - priority of the current node (higher values mean higher
priority)
• 255 - RFC requires that the router that owns the IP addresses assigned to this instance had the
priority of 255
interval (integer: 1..255; default: 1) - VRRP update interval in seconds. Defines how frequently the
master of the given cluster sends VRRP advertisement packets
preemption-mode (yes | no; default: yes) - whether preemption mode is enabled
• no - a backup node will not be elected to be a master until the current master fail even if the
backup node has higher priority than the current master
• yes - the master node always has the priority
authentication (none | simple | ah; default: none) - authentication method to use for VRRP
advertisement packets
• none - no authentication