doc/nat: update config options
@@ -46,6 +46,8 @@ Configuration Options
``CONFIG_NET_NAT``
Enable or disable Network Address Translation (NAT) function.
Depends on ``CONFIG_NET_IPFORWARD``.
+``CONFIG_NET_NAT_HASH_BITS``
+ The bits of the hashtable of NAT entries, hashtable has (1 << bits) buckets.
``CONFIG_NET_NAT_TCP_EXPIRE_SEC``
The expiration time for idle TCP entry in NAT.
The default value 86400 is suggested by RFC2663, Section 2.6,
@@ -55,6 +57,14 @@ Configuration Options
The expiration time for idle UDP entry in NAT.
``CONFIG_NET_NAT_ICMP_EXPIRE_SEC``
The expiration time for idle ICMP entry in NAT.
+``CONFIG_NET_NAT_ENTRY_RECLAIM_SEC``
+ The time to auto reclaim all expired NAT entries. A value of zero will
+ disable auto reclaiming.
+ Expired entries will be automatically reclaimed when matching
+ inbound/outbound entries, so this config does not have significant
+ impact when NAT is normally used, but very useful when the hashtable
+ is big and there are only a few connections using NAT (which will
+ only trigger reclaiming on a few chains in hashtable).
Usage
=====
