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- Improved Reliability and Resiliency: Anycast provides improved reliability, because DNS queries are sent to an Anycast IP address. If the nearest server somehow goes offline, the router forwards the request to the next nearest DNS server advertising the target Anycast IP address.
- OSPF and BGP Protocols: Anycast uses both Open Shortest Path First (OSPF) and Border Gateway Protocol (BGP).
- Load Distribution: Anycast distributes the load across multiple DNS servers based on network topology. Dynamic routing enables a fully flexible and path-optimized DNS packet flow.
BloxOne DDI Cloud provides multiple Anycast IPv4 addresses to improve resiliency and reliability. Infoblox recommends that you provision your network firewalls and allow traffic to the following ports:
| 53 | udp |
| 53 | tcp |
| 443 | tcp |
| Note |
|---|
Due to an anycast limitation, there is no option to provide routing ID in the routing configuration. You will not be able to configure anycast advertising on a VLAN interface or multiple interfaces. Anycast will choose the WAN interface by default. For information about creating an anycast service instance, see Configuring Anycast Service Settings. |
Anycast and OSPF
A host hardware device or virtual machine appliance can use the OSPF routing protocol to advertise routes for DNS anycast addresses to an upstream router within the autonomous system. The upstream router uses the OSPF advertisement to determine the nearest DNS server from a group of servers within the internetwork. In practice, the NIOS appliance relies upon OSPF to determine the best route for DNS queries to take to the nearest DNS server. The upstream router then forwards the query to the chosen DNS server.
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