SNAT 和 DNAT 的区别

1. 源网络地址转换(SNAT)：
SNAT，顾名思义，是一种通常在从私有 IP 地址连接到公共 IP 地址时转换源 IP 地址的技术。它将请求中的源客户端 IP 地址映射到 BIG-IP 设备上定义的转换。当内部主机需要向外部主机或公共主机发起会话时，使用它是最常见的 NAT 形式。

2.目的网络地址转换(DNAT)：
DNAT，顾名思义，是一种通常在从公共 IP 地址连接到私有 IP 地址时转换目标 IP 地址的技术。它通常用于将目的地为特定 IP 地址或 IP 地址上的特定端口的数据包重定向到一个主机上的不同地址，主要是在不同的主机上。

SNAT 和 DNAT 的区别：

SNAT	DNAT
It is generally used to change private address or port into a public address or port for packets leaving network.	It is generally used to redirect incoming packets with destination of public address or port to private IP address or port inside network.
It translates source IP address within a connection to BIG-IP system IP address that one defines.	It translates IP addresses of internal servers that are protected by device to public IP addresses.
It is used to change source address of packet.	It is used to change destination address of packet.
It also changes source port in TCP/UDP headers.	It also changes destination port in TCP/UDP headers.
It generally allows multiple hosts on inside to get any host on outside.	It generally allows multiple hosts on outside to get single host on inside.
It is performed after routing decision is made.	It is performed before routing decision is made.
In this, destination IP address is maintained and source IP address is changed.	In this, source IP address is maintained and destination IP address is changed.
Client inside LAN and behind Firewall needs to browse Internet.	Website hosted inside data center behind Firewall and needs to be accessible to users over Internet