Virtual Router Passport Fddi ETB Preserve Domain

This attribute specifies if the domain information should be preserved or embedded in the frame header. This attribute applies only to backbone ports and does not affect the access bridge ports. By setting this attribute to a value of on, domain information could be preserved in frames being tunnelled across the a backbone, so that this information can be deciphered at the other end of the backbone tunnel. This preserves the integrity of the domains thus preventing domain breaches while tunnelling frames across backbone network. If the value of this attribute is set to off then domain information is not preserved in the header of the frames tunnelling through the backbone. This eliminates the overhead incurred to preserve domain information across the backbone while tunnelling frames across it. Preserve domain is relevant when used in conjunction with the following media: FDDI, ATM MPE, Frame Relay and PPP. It is ignored when used with other types of media.