GRE三层封装技术
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GRE封装
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GRE IP协议号是47
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IP Header TCP Header
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GRE 建立过程
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FW GRE VPN配置
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隧道keepalive检测机制
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华为路由器 keepalive默认5S 发一次检测数据包 尝试3次。一侧设备配置就可以。
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keepalive 功能默认是关闭。
FW 默认时间是5S
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检测超时后 端口会down
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隧道中传输的数据是透明的
如下图 可以看到 ospf 报文
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GRE隧道如何加密?
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IPsec隧道数据包格式
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