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Forum Replies

  1. IPv6 uses the link-local addresses as the next-hop for routing entries so there is no need to configure a “global” IPv6 address.

  2. The major differences:

    MCT - MTU is 1480, less overhead, supports only a single passenger protocol, mode is ipv6ip.

    GRE - MTU is 1476, more overhead, supports multiple passenger protocols, mode is gre.

  3. MCT? Is that the manual mode?

  4. Hello Chris

    I belive what @zz.alnajjar is referring to is a Manually Configured Tunnel (MCT) although it does not have an official such name. What the manually configured tunnel is, is an IP packet inside an IP packet. A doubly encapsulated packet. If this is configured, the overhead will just be 20 bytes, which is the size of the header of a standard IPv4 packet, thus prodcing an MTU of 1500-20 = 1480. GRE on the other hand has a header of 24 bytes providing an MTU of 1500-24 = 1476.

    More info can be found on page 2 of this Cisco Documentation.

    I hope this has been helpful!


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