GEO redirection not working for some users

A customer implemented GEO IP redirection using example provided here Implementing GEO IP redirects in

They asked:

We have just had a report that some of our Australian Customers are reaching the USA site.
Can you just do a quick check to see if any redirections have stopped working?
It seems to happen to about 5 customers, all other AU customers were being redirected correctly.

It is very common for IP address range to change regions. I suspect that an IP range that used to be allocated to the US region may have been recently reallocated to the AU region.

Our GEO IP uses Maxmind GEO IP databases which are updated frequently. If the above scenario occurred then Maxmind will update their database soon and these users will stop having the issue. You can also implement a temporary ACL whitelist with affected customer IP addresses in Varnish to make exceptions from the normal GEO redirect rules and direct them to the region of your choosing.