In a mission critical WAN connection in the organization, router redundancy should be used. There are many integrated firewall and VPN appliances provide dual WAN link for business networks available in the market which can be configured for load balancing or fail-over. In a fail-over system, when the primary connection fails to function the system will fail-over to the backup connection. Many types of routers include two or more WAN ports to let you use fail-over or load balancing.
Building a large network infrastructure for mission critical networks, having router redundancywith redundant WAN connections is an effective method for ensuring network high availability in the event of a core router or primary link failure. Small businesses can deploy any types of multi WAN routers with load balancing and fail-over feature.
In enterprise networks generally they deploy high end routers and switches with the minimum requirement with regards to Router Redundancy as follows:
- In environments where network high availability (router and link) is required, a router redundancy solution should be deployed.
- Either VRRP (Virtual Router Redundancy Protocol) or HSRP (Cisco’s Hot Standby Routing Protocol) can be used for router redundancy.
- Protocols such as client based RIP, Proxy-ARP and IRDP must not be used as a router redundancy solution.
- Network failover (convergence) time must be less than 10 seconds (5 seconds ideally).
Router Redundancy Diagram
Router redundancy is provided by utilizing dual routers running a router redundancy protocol such as VRRP (Virtual Router Redundancy Protocol) or HSRP (Cisco’s Hot Standby Routing Protocol). This should also be used in conjunction with redundant WAN connections. This provides a high available solution which is transparent to user devices.
Many other immature solutions require client agents on the device or generate significant network overhead. Many of these solutions are also slow to converge and often require client reconfiguration. Both VRRP and HSRP can provide transparent high availability solutions that converge in under a few seconds.
Cisco routers currently only support HSRP. HSRP is a Cisco proprietary protocol which has recently been submitted to the IETF (Informational RFC 2281) for review. Consult Cisco Systems for more information on HSRP. VRRP is universal standards protocol defined in RFC 2338.
The following section provides a brief overview of VRRP and HSRP:
HSRP\VRRP requires no client agents, but rather the client utilizes a virtual IP address for its default gateway. The client sends all inter-network data to this virtual router address. An active router takes on the network characteristics of this virtual IP address, whilst a standby router periodically polls the active router to ensure the router is performing its assigned forwarding tasks. See also other Cisco proprietary routing protocol: EIGRP routing protocols which converge very fast and also industrial routing protocols OSPF routing protocols.
HSRP\VRRP is configured such that if the active router fails, the standby router takes over the active roll almost instantaneously. The client continues to successfully forward data via the virtual VRRP/HSRP router without any knowledge of the router failure
If router redundancy is not used then a single router failure will stop all internetwork communications.
For small businesses that demand fail-over or load balancing feature can use the following routers for redundancy requirements:
Cisco RV082 8-port 10/100 VPN Router – Dual WAN
Cisco RV082 is a dual WAN router which includes VPN features and supports load balancing and fail-over feature. The router is equipped with eight fast Ethernet ports (10/100Mbps) for wired connection to the computers with NIC adapter.
Cisco RV082 supports full IPSec VPN capabilities with up to 100 remote connections. For protection against any threats the router includes advanced SPI firewall.
Read more details about RV082 manufacturer’s description and spec details.
TL-R4299G Dual WAN router for Internet café / businesses
The TP-Link TL-R4299G is a dual WAN router which includes eight gigabit Ethernet LAN ports. The router supports load balancing that selects the lines automatically according to the loads. The router supports IP and Port based Quality of Services to help you provide high performance that demands bandwidth sensitive applications such as video Tele-conference, streaming multimedia and gaming.
See more detail the TL-R4299G Dual WAN router spec details.
FVS336G Dual Wan Gigabit SSL VPN Firewall
The Netgear FVS336G is a dual Wan Gigabit SSL VPN Firewall which supports up to 25 IPSec VPN tunnels and 10 SSL VPN tunnels simultaneously. The router includes two WAN ports to let you configure as the load balancing or fail-over. The router includes four gigabit Ethernet LAN ports with auto-sensing and auto-uplink.
Click here for more details Netgear FVS336G dual WAN gigabit firewall.
Router redundancy is used in a mission critical environment where uninterruptable internet connection is required. There are many routers which supports dual WAN ports for load balancing or fail-over feature available in the market today for small businesses.
