設定內部兩台WEB主機可以自動切換

ison

上敘兩種方法 NTH 及 PCC，會發現 NTH 並不適合作 Web Load Balancer，這樣會造成 session 異常，所以必須採用 PCC 方式，以下就採用 PCC 進行設定。

下圖為範例結構：

WAN：1.1.1.1

MikroTik RouterOS LAN：192.168.1.1

Web Server1：192.168.1.2

Web Server2：192.168.1.3
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/ip firewall mangle

add action=mark-connection chain=prerouting comment=Web1 dst-address=1.1.1.1 dst-port=80 new-connection-mark=Web1 passthrough=yes per-connection-classifier=both-addresses-and-ports:2/0 protocol=tcp

add action=mark-connection chain=prerouting comment=Web2 dst-address=1.1.1.1 dst-port=80 new-connection-mark=Web2 passthrough=yes per-connection-classifier=both-addresses-and-ports:2/1 protocol=tcp

/ip firewall nat

add action=dst-nat chain=dstnat comment=Web1 connection-mark=Web1 dst-address=1.1.1.1 dst-port=80 protocol=tcp to-addresses=192.168.1.2 to-ports=80
add action=dst-nat chain=dstnat comment=Web2 connection-mark=Web2 dst-address=1.1.1.1 dst-port=80 protocol=tcp to-addresses=192.168.1.3 to-ports=80

add action=dst-nat chain=dstnat comment="Web1 Default" dst-address=1.1.1.1 dst-port=80 protocol=tcp to-addresses=192.168.1.2 to-ports=80
add action=dst-nat chain=dstnat comment="Web2 Default" dst-address=1.1.1.1 dst-port=80 protocol=tcp to-addresses=192.168.1.3 to-ports=80

/tool netwatch
add comment=Web1 down-script="/ip firewall nat disable [find comment=\"Web1\"]\
    ;\r\
    \n/ip firewall nat disable [find comment=\"Web1 Default\"];" host=192.168.1.2 \
    interval=5s timeout=5s up-script="/ip firewall nat enable [find comment=\"\
    Web1\"];\r\
    \n/ip firewall nat enable [find comment=\"Web1 Default\"];"
add comment=Web2 down-script="/ip firewall nat disable [find comment=\"Web2\"]\
    ;\r\
    \n/ip firewall nat disable [find comment=\"Web2 Default\"];" host=192.168.1.3 \
    interval=5s timeout=5s up-script="/ip firewall nat enable [find comment=\"\
    Web2\"];\r\
    \n/ip firewall nat enable [find comment=\"Web2 Default\"];"