Introduction:
In a multiple WAN network, link load balancer or firewall usually decides the outbound path for a destined domain with the IP address from its first DNS query. When new requests to the same destined domains arise later, they will take the same path only if the destined domain name servers respond them with same IP address. However, some large organizations usually have more than one IP addresses for their domain names, and randomly respond DNS queries with different IP addresses from time to time. Therefore, path decisions made by the IP routing rule created based on the result of first DNS query can hardly work accurately as domain server would respond the queries with IP address differently. In this case, the traffic will be directed to different path(s).
With the advanced mechanism of Domain Name Routing, Q-Balancer is now able to precisely route outbound requests to the Internet via the particular WAN gateway.
Diagram Example:
Requirements:
In this case, the appliance is requested to direct all traffic to the Internet via WAN 1 and WAN 2 at the same time, while LAN users can still access the Internet when/if one of the WAN links is down or saturated. Also, it needs to direct traffic to all education organizations in Taiwan via WAN 2, and via WAN 1 in case WAN 2 is down.
Configuration:
Step 1. WAN > ADD > Static
WAN 1:
WAN 2:
WAN configuration is done as follows:
Step 2. LAN > ADD
LAN configuration is done as follows:
Step 3. Object > Host > ADD > FQDN
Host Object configuration is done as follows:
Step 4. Object > DPS > ADD > Weight Round Robin by Connection
This is for LAN users to access the Internet via both WAN links:
Step 5. Object > DPS > ADD > Priority
Sending traffic destined for all.edu.tw via WAN 2, and via WAN 1 if/when WAN 2 is down is set as follows:
DPS configuration is done as follows:
Step 6. Policy Routing > ADD
The following is for all traffic to the Internet:
The following is for the traffic destined for all.edu.tw:
Policy Routing for traffic destined for all.edu.tw is done as follows:
