The difference between static and dynamic for Fastly’s Varnish is that for static the hostname is resolved to an IP address at VCL compilation time. Dynamic means that we resolve constantly (whenever the TTL on the DNS record is expired when a probe is performed.)
We have found though, that in a large number of the cases where people did not put
.dynamic = true;, they did actually need it.
So we’ve decided to make it mandatory if you use a
.host that is not an IP address.
So if the addresses are truly static, just use IPs. If you want a change in address for the hostname to reflect as soon as possible (given TTLs), use a hostname and set
.dynamic = true;