On some systems, error messages indicating that the route cache is full, are emitted when using IPv6. An error similar to the following example may be returned:

[ 5523.456447] Route cache is full: consider increasing sysctl
net.ipv[4|6].route.max_size.

It is unclear what causes these errors or to what size /proc/sys/net/ipv6/route/max_size should be increased; but, on a test system, the issue could not be replicated after running the following command:

sudo sysctl net.ipv6.route.max_size=32768

Because the issue is currently under investigation, increasing this value is a viable workaround.

(Bug ID 30976607)