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how is tunnel checksum calculated?

does anyone know how the the tunnel checksum is calculated?...it it md5?

john

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Re: how is tunnel checksum calculated?

If you are referring to GRE, then it uses 1's complement method to calculate the checksum. Zero the checksum field, take the 1's complement sum of the payload + GRE header, then take a 16 bit 1's compliment of the previous result, to get the final checksum.

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Re: how is tunnel checksum calculated?

If you are referring to GRE, then it uses 1's complement method to calculate the checksum. Zero the checksum field, take the 1's complement sum of the payload + GRE header, then take a 16 bit 1's compliment of the previous result, to get the final checksum.

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