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DNS Cache

Last Updated: Mar 15, 2021

    Overview

    DNS Cache is a Domain Name System (DNS) proxy that enables you to use the infrastructure of Alibaba Cloud DNS without DNS migration. DNS Cache can help enterprises improve the capabilities in DNS protection, DNS access speed, and backup for DNS servers.

Benefits

  • Distributed denial of service (DDoS) attack mitigation: DNS Cache caches DNS responses to protect your authoritative DNS servers from DDoS attacks and reduce the load on your authoritative DNS servers.

  • DNS access acceleration: Alibaba Cloud DNS provides global nodes. DNS Cache allows you to access the nearest node and accelerates the access speed.

  • Backup for DNS servers: When an error occurs in authoritative domain names, DNS Cache allows you to use the service before the cached DNS records expire. This shorter the time wasted by failures.

  • Cost-effectiveness: If you use an on-premises DNS, DNS Cache can help you reduce bandwidth usage to save costs.

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    GUI element description

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    1. Cached Public Zone

    The name of the domain that you want to enable cache acceleration. Both the domain name and subdomain name are supported.

    2. Source DNS Servers

    The address and port of the authoritative DNS servers. If the address of the authoritative server is ns1.alidns.com, ns1.alidns.com:53 is displayed in the Source DNS Servers column.

    3. DNS Access Status

    The status of whether DNS Cache accesses the DNS servers.

    Status

    Description

    Solution

    Normal

    The DNS servers of the domain name are not changed to cache1.alidns.com and cache2.alidns.com and DNS Cache can access the DNS servers.

    N/A

    Have not used AlibabaCloudDNS

    The DNS servers of the domain name are not changed to cache1.alidns.com and cache2.alidns.com.

    Change the DNS servers of the domain name to cache1.alidns.com and cache2.alidns.com.

    Running exception

    The DNS servers of the domain name cannot be queried.

    DNS server status

    Procedure

    1. Log on to the Alibaba Cloud DNS console.

    2. In the left-side navigation pane, click Manage DNS. On the Manage DNS page, click the Cached Public Zone tab.

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    3. Click Create Cached Public Zone and configure a domain name with cache acceleration.

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    Set the following parameters:

    Cached Public Zone: the domain name for which you want to implement cache acceleration.

    Bound Instances: the instance that you want to bind. You can select an instance of the Cached Public Zone type that you have purchased. If no instance is displayed in the drop-down list, click Buy Instance to buy one.

    TTL for Source Cached Data (Min. Value) and TTL for Source Cached Data (Max. Value): the minimum and maximum time-to-live (TTL) during which the DNS records of the domain name with cache acceleration are effective. Unit: seconds. Valid values: 30 to 86400.

    Note

    After cache acceleration is enabled, the TTL of the on-premises DNS is subject to the TTL specified when you configure cache acceleration. If the service provider extends the TTL, contact the service provider to resolve the issue.

    Source DNS Query Protocol: Resolution requests are sent to authoritative servers over UDP. Only UDP is supported.

    Source DNS Server Supports edns-client-subnet: You can select this check box if your authoritative server supports the Extension mechanisms for DNS (EDNS) protocol. Assume that the on-premises DNS also supports the EDNS protocol. When the on-premises DNS sends a recursive resolution request, DNS Cache will send the IP address of the client to your origin DNS server.

    Source DNS Servers: You can specify one or more origin DNS servers. The default port is 53. You can specify the actual port of the origin DNS servers.

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