O tempo limite é configurável em /etc/resolv.conf com o parâmetro timeout .
Tente adicionar a linha: option timeout:<desired timeout in seconds> a /etc/resolv.conf .
Da página de manual resolv.conf :
timeout:n
sets the amount of time the resolver will wait for a response from a remote name server before retrying the
query via a different name server. Measured in seconds, the default is RES_TIMEOUT (currently 5, see
<resolv.h>). The value for this option is silently capped to 30.
Os créditos vão para o link .