56 lines
1.8 KiB
Plaintext
56 lines
1.8 KiB
Plaintext
When NetScaler application switch is used as L3+ switch, informations
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regarding the original IP and TCP headers are lost as a new TCP
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connection is created between the NetScaler and the backend server.
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NetScaler provides a feature to insert in the TCP data the original data
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that can then be consumed by the backend server.
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Specifications and documentations from NetScaler:
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https://support.citrix.com/article/CTX205670
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https://www.citrix.com/blogs/2016/04/25/how-to-enable-client-ip-in-tcpip-option-of-netscaler/
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When CIP is enabled on the NetScaler, then a TCP packet is inserted just after
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the TCP handshake. Two versions of the CIP extension exist.
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Legacy (NetScaler < 10.5)
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- CIP magic number : 4 bytes
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Both sender and receiver have to agree on a magic number so that
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they both handle the incoming data as a NetScaler Client IP insertion
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packet.
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- Header length : 4 bytes
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Defines the length on the remaining data.
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- IP header : >= 20 bytes if IPv4, 40 bytes if IPv6
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Contains the header of the last IP packet sent by the client during TCP
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handshake.
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- TCP header : >= 20 bytes
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Contains the header of the last TCP packet sent by the client during TCP
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handshake.
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Standard (NetScaler >= 10.5)
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- CIP magic number : 4 bytes
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Both sender and receiver have to agree on a magic number so that
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they both handle the incoming data as a NetScaler Client IP insertion
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packet.
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- CIP length : 4 bytes
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Defines the total length on the CIP header.
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- CIP type: 2 bytes
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Always set to 1.
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- Header length : 2 bytes
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Defines the length on the remaining data.
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- IP header : >= 20 bytes if IPv4, 40 bytes if IPv6
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Contains the header of the last IP packet sent by the client during TCP
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handshake.
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- TCP header : >= 20 bytes
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Contains the header of the last TCP packet sent by the client during TCP
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handshake.
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