Multiple Internet Connections Configuration Notes

To better understand how to configure and use multiple Internet connections, let’s look at the following scenario.

 

Network Topology

A business uses two routers (HiPER 4240G and HiPER 841) to connect to the Internet. In total there are seven broadband Internet connections, three of them via the HiPER 4240G, and the rest via the HiPER 841. The HiPER 841’s LAN interface is connected to the HiPER 4240G’s WAN4 interface, and all the internal hosts are connected to the HiPER 4240G’s LAN interface to access the Internet.

 

Symptom

The user reported that after pulling out the cable between the HiPER 4240G and 841, all the internal hosts are unable to access the Internet unless the WAN4 connection on the HiPER 4240G has been deleted.

 

Analysis

1. When configuring multiple Internet connections, do not forget to configure connection detection. Note that connection detection is required for a Static IP connection, but optional for a PPPoE connection as it automatically uses LCP Echo mechanism to validate link availability.

2.  For a Static IP Internet connection, we suggest you bind the gateway MAC address with its IP address to prevent external ARP spoofing attacks. In this scenario, we need to bind the IP and MAC address pairs of the two interfaces (HiPER 4240G’s WAN4 interface and HiPER 841’s LAN interface) respectively.

3.In this scenario, because the HiPER 841’s LAN interface is connected to the HiPER 4240G’s WAN4 interface, and all the internal hosts are directly connected to the HiPER 4240G, we only need to configure rate limit on the HiPER 4240G.

 

Configure Internet connections

 

 

Configure Internet connection detection

Go to the Basic > Load Balancing > Global Settings page to specify the Detection Method. In most cases, we suggest you use the default ICMP detection method.

 

 

Specify the Detection Target IP (either the default gateway IP address, or another public IP address always available) for each Internet connection respectively.

 

 

 

To maximize bandwidth usage, we need to assign different weights to Internet connections according to their bandwidth. In this scenario, WAN1, WAN2, WAN3 and WAN4 bandwidth are 2M, 2M, 2M and 8M (4 × 2M), so we can set their weight to 1, 1, 1, and 2 respectively.

 

 

Go to Basic > WAN > WAN4 page to bind the gateway MAC address with the gateway IP address to prevent external ARP spoofing attacks. In this scenario, the HiPER 841’s LAN interface is the HiPER 4240G’s WAN4 gateway.

 

 

 

Configure rate limit.

Because the HiPER 841’s LAN interface is connected to the HiPER 4240G’s WAN4 interface, we only need to configure rate limit on the HiPER 4240G: Go to the QoS > Global Settings page to enable rate limit feature and specify Capacity, and then go to the QoS > Rate Limit Rule page to create rate limit rules according to actual user requirements.

 

 

 

Conclusion

After some troubleshooting, we found that the problem was that connection detection was disabled on the HiPER 4240G. If connection detection is disabled, a Static IP Internet connection will still be regarded as normal after pulling out the corresponding cable, and the traffic through that connection cannot be redirected to other available connections. As a result, the related Internet applications will be interrupted.

 

Configuration Considerations

Take into account the following considerations when you configure and use multiple Internet connections.

 

1.Configure Internet connection detection, especially for static IP Internet connection.

2.Assign different weights to Internet connections according to their bandwidth.

3.For a Static IP Internet connection, we suggest you bind the gateway MAC address with its IP address to prevent external ARP spoofing attacks.

4.Configure rate limit to assign different limits to different users, or groups.

5.To protect your network from from internal attacks, configure security settings, such as IP/MAC binding, DDoS attacks defense, blaster virus defense, and so on.