Method of preserving symmetrical routing in a communication system based upon a server farm
View Patent ↗A method of preserving symmetrical routing in a communication system comprising a server farm connected to the Internet through an Internet access router. The server farm includes at least two customer cabinets with at least a WEB server and at least two firewalls. The firewalls use a Virtual Router Redundancy Protocol (VRRP) to set up one firewall as being the primary firewall. The method includes checking in each firewall whether there is a change of the VRRP state from primary to secondary or reciprocally. Such a change indicates that a link between the primary firewall and one of the customer cabinets has failed. The link is disabled from the network to the firewall the state of which has changed from primary to secondary or the link is enabled from the Internet network to the firewall the state of which has changed from secondary to primary.
1. A method of preserving symmetrical routing in a communication system said method comprising the steps of:
providing a server farm connected to an Internet by an Internet front-end including at least an Internet access router, said server farm further comprising:
a plurality of customer cabinets with each customer cabinet including at least one WEB server and server farm resources enabling users connected to the Internet to access the at least one WEB server in each of the plurality of customer cabinets;
a plurality of firewalls for controlling communication between users and the at least one WEB server, said plurality of firewalls using Virtual Router Redundancy Protocol (VRRP) to set one of the plurality of firewalls a primary firewall which owns a primary interface of a VRRP group of interfaces to at least one of the plurality of customer cabinets and to establish communication between an Internet user and said at least one WEB server;
checking in each of said plurality of firewalls whether there is a change of VRRP state from primary to secondary or from secondary to primary; and
disabling an interface from said Internet to said firewall if the VRRP state has changed from primary to secondary, or enabling an interface from said Internet to said firewall if the VRRP state has changed from secondary to primary.
2. The method according to claim 1 , further comprising a step of monitoring whether the VRRP state has changed before the checking step.
3. The method according to claim 2 , further comprising a step of reading the VRRP state if the VRRP state has not changed.
4. The method according to claim 1 , wherein the server farm resources comprise at least one intermediary switch.
5. The method according to claim 1 , wherein the Internet front-end further comprises a LAN.