No Check Zero field: Specifies that IGRP should not check that reserved fields are zero in incoming IGRP request packets. This field displays only when the Use protocol defaults field is set to off. Normally IGRP will reject request packets when the reserved fields are not zero. The reserved fields in a request packet are the edition number and the three route counts. Also, by enabling this option, any possible trailing data after the IGRP header will be ignored. Normally, IGRP will reject request packets that are not exactly the size of the IGRP header.
Range: Yes/No
Default: No (zero check is performed)