Name

nexp-gre — Generic Routing Encapsulation (GRE) support for Network Expect

Synopsis

PDU definition:

gre ( [ proto=num,] [ cksum ] )

PDU Definition

The following parameters allow you to define the different parts of a GRE protocol data unit (PDU) in Network Expect:

proto = NUMSPEC

Specifies the value of the Protocol field in the GRE header. Default: Ethertype of tunneled protocol if known; zero if unknown.

cksum

Sets the checksum flag of the GRE PDU and instructs Network Expect to compute and store the checksum in the GRE header.

PDU Decoding

The current version of Network Expect does not support the decoding of received GRE PDUs into the Tcl array variable gre.

Examples

  1. A simple GRE packet.

    ip(dst = www.netexpect.org)/gre()
    	
  2. A GRE packet containing a checksum:

    ip(dst = www.netexpect.org)/gre(cksum)
    	
  3. A GRE packet containing an IP packet destined to 10.1.1.1:

    ip(dst = www.netexpect.org)/gre()/ip(dst = 10.1.1.1)
    	
  4. A GRE packet with a specific protocol field and raw payload:

    ip(dst = www.netexpect.org)/gre(proto = 0x4141)/raw('AA')
    	

VERSION

This man page is correct for version 1.0 of Network Expect.

SEE ALSO

nexp(1), nexp-numspec(5), RFC 2784

AUTHOR

Generic Routing Encapsulation support for Network Expect was written by Eloy Paris <peloy@netexpect.org>.

This man page was written by Tim Sammut <tsammut@cisco.com>.