def nameservers_for_device(n_ip)
      nameservers = []
      raw_nameservers = ENV["RS_IP#{n_ip}_NAMESERVERS"].to_s.strip.split(/[, ]+/)
      raw_nameservers.each do |nameserver|
        if valid_ipv4?(nameserver)
          nameservers << nameserver
        else
          # Non-fatal error, we only need one working
          logger.error("Invalid nameserver #{nameserver} for interface##{n_ip}")
        end
      end
      # Also a non-fatal error, DHCP or another interface specify nameservers and we're still good
      logger.warn("No valid nameservers specified for static interface##{n_ip}") unless nameservers.length > 0
      nameservers
    end
def nameservers_for_device(n_ip)
      nameservers = []
      raw_nameservers = ENV["RS_IP#{n_ip}_NAMESERVERS"].to_s.strip.split(/[, ]+/)
      raw_nameservers.each do |nameserver|
        if valid_ipv4?(nameserver)
          nameservers << nameserver
        else
          # Non-fatal error, we only need one working
          logger.error("Invalid nameserver #{nameserver} for interface##{n_ip}")
        end
      end
      # Also a non-fatal error, DHCP or another interface specify nameservers and we're still good
      logger.warn("No valid nameservers specified for static interface##{n_ip}") unless nameservers.length > 0
      nameservers
    end
Returns a validated list of nameservers

 == Parameters
 none