Suricata

Yaml default:

decoder:
  # Teredo decoder is known to not be completely accurate
  # as it will sometimes detect non-teredo as teredo.
  teredo:
    enabled: true
    # ports to look for Teredo. Max 4 ports. If no ports are given, or
    # the value is set to 'any', Teredo detection runs on _all_ UDP packets.
    ports: $TEREDO_PORTS # syntax: '[3544, 1234]' or '3533' or 'any'.

Code default:

static bool g_teredo_enabled = true;
static bool g_teredo_ports_any = true;
static int g_teredo_ports_cnt = 0;
static int g_teredo_ports[TEREDO_MAX_PORTS] = { TEREDO_UNSET_PORT, TEREDO_UNSET_PORT,
    TEREDO_UNSET_PORT, TEREDO_UNSET_PORT };

These defaults should be aligned, with probably the code default following the current yaml default.