The customer needs that when the primary link goes down, the system continues to operate on the secondary link

If I'm not mistaken, management of the DNS cache is your responsibility.

If you're relying on the private link that every Linode gets for this switchover, you're going to have problems…that link is limited to connecting to Linodes in the same datacenter only.

If you need a 2nd link with a 2nd IP address, you'll have to contact support. However, you'll have to configure it yourself and management of the DNS cache will still be your responsibility.

-- sw

Hi,

Not sure exactly what you're asking, but perhaps add options rotate to your /etc/resolv.conf ?

From the man page:

rotate Sets RES_ROTATE in _res.options, which causes round-robin selection of name servers from among those listed. This has the effect of spreading the query load among all listed servers, rather than having all clients try the first listed server first every time.

HTH,
-Chris

Chris --

You wrote:

Not sure exactly what you're asking, but perhaps add options rotate to your /etc/resolv.conf ?

This is helpful information to the OP but not relevant to the management of the DNS cache. If the OP wants control over the DNS cache (not sure why given the original question), he needs to do it himself:

https://geekflare.com/linux-server-local-dns-caching/

Of course, like all things Linux these days, it involves doing battle with systemd(1) to bring up a local-caching name server. Which "global" DNS server is used for a particular query is not relevant to the cache…since a DNS request will be satisfied from the local cache if it can be. Satisfaction of DNS requests involving local cache hits happens BEFORE the hardware is bothered…

This message is more for the OP than for you…

-- sw