Method of preserving symmetrical routing in a communication system based upon a server farm

A method of preserving symmetrical routing in a communication system comprising a server farm connected to the Internet by an Internet front-end including at least an Internet access router, said server farm comprising at least two customer cabinets with each customer cabinet including at least a WEB server and server farm resources enabling users connected to the Internet to access the WEB servers in said customer cabinets, and at least two firewalls for controlling communication between users and one of said WEB servers, said firewalls using Virtual Router Redundancy Protocol (VRRP) to set up as primary firewall a firewall which owns a primary interface of the VRRP group of interfaces to at least one customer cabinet and through which is established communication between an Internet user and said customer server;

• said method comprising the steps of:
• a) checking in each of said firewalls whether there is a change of VRRP state from primary to secondary or from secondary to primary and,
• b) disabling an interface from said network to said firewall the state of which has changed from primary to secondary, or enabling an interface from said Internet network to said firewall the state of which has changed from secondary to primary.