I’m doing a connection of 2 sites in ipv6 over an ipv4 network. I thought to do a tunnel between this 2 sites and protect it with IPsec. But I saw there are different types of tunnels (by default GRE):

  aurp    AURP TunnelTalk AppleTalk encapsulation
  cayman  Cayman TunnelTalk AppleTalk encapsulation
  dvmrp   DVMRP multicast tunnel
  eon     EON compatible CLNS tunnel
  gre     generic route encapsulation protocol
  ipip    IP over IP encapsulation
  iptalk  Apple IPTalk encapsulation
  ipv6ip  IPv6 over IP encapsulation
  nos     IP over IP encapsulation (KA9Q/NOS compatible)

What are the differences?

I saw there is a possibility to make IPsec with MAPs and access lists. Could this work too? I didn’t saw a possibility to append an ipv6 access list to a crypto map…

1 Answer 1



Initially designed by Apple Inc. to connect Macintosh computers to printers and file servers in small workgroups, the AppleTalk protocol was later deployed in larger LAN and WAN configurations. While TCP/IP has become the prominent customer choice of protocols, Cisco kept the AppleTalk protocol on its Cisco IOS Software to satisfy the demand in some niche markets such as education and scientific communities.

Due to a significant decrease in Appletalk usage and demand among its customer base, and given the fact that Apple now fully supports the TCP/IP family of protocols, Cisco has reached the decision to discontinue AppleTalk support on Cisco IOS.

The AppleTalk feature removal will be permanent and will also apply to any future IOS releases after 12.4(24)T. This removal will also propagate to other IOS release trains in future (updated product bulletins will be released for other trains).

The following features will be removed from Cisco IOS Software after Release 12.4(24)T:
• AppleTalk Phase 1 and Phase 2 support
• AppleTalk Update-Based Routing Protocol (AURP)
• AppleTalk Tunneling
• AppleTalk Remote Access Protocol (ARAP)
• AppleTalk Access Lists
• All other AppleTalk related features

Cayman Tunneling

Designed by Cayman Systems, Cayman tunneling enables tunneling to enable Cisco routers to interoperate with Cayman GatorBoxes. With Cayman tunneling, you can establish tunnels between two routers or between a Cisco router and a GatorBox. When using Cayman tunneling, you must not configure the tunnel with an AppleTalk network address.


Use DVMRP when a router connects to an mrouted (multicast) router to run DVMRP over a tunnel. You must configure Protocol Independent Multicast (PIM) and an IP address on a DVMRP tunnel.


The ISO Connectionless Network Service (CLNS) protocol is a standard for the network layer of the OSI model. IP traffic can be transported over CLNS; for instance, on the data communications channel (DCC) of a SONET ring. An IP over CLNS tunnel (CTunnel) is a virtual interface that enhances interactions with CLNS networks, allowing IP packets to be tunneled through the Connectionless Network Protocol (CLNP) to preserve TCP/IP services. CLNS can also be used as a transport protocol with GRE as a carrier protocol (GRE/CLNS), carrying both IPv4 and IPv6 packets.


Generic routing encapsulation (GRE) is defined in RFC 2784. GRE is a carrier protocol that can be used with a variety of underlying transport protocols, and GRE can carry a variety of passenger protocols. RFC 2784 also covers the use of GRE with IPv4 as the transport protocol and the passenger protocol. Cisco IOS software supports GRE as the carrier protocol with many combinations of passenger and transport protocols.


Use the ipip keyword to specify that IP-in-IP encapsulation will be used. The optional decapsulate-any keyword terminates any number of IP-in-IP tunnels at one tunnel interface. Note that this tunnel will not carry any outbound traffic; however, any number of remote tunnel endpoints can use a tunnel configured this way as their destination.


IPTalk is a protocol for encapsulating AppleTalk packets in IP datagrams. IPTalk is used to route AppleTalk packets across non-AppleTalk backbones and to communicate with applications on hosts that cannot otherwise communicate via AppleTalk, such as the Columbia AppleTalk Package (CAP). IPTalk also allows serial connections to use IPTalk Serial Line Internet Protocol (SLIP) drivers.


Use the ipv6ip keyword to specify that IPv6 will be used as the passenger protocol and IPv4 as both the carrier (encapsulation) and transport protocol. When additional keywords are not used, manual IPv6 tunnels are configured. Additional keywords can be used to specify IPv4-compatible, 6to4, or ISATAP tunnels.


The nos command is used to establish an nos style tunnel, (also known as ka9q or IP-IP tunnel).

Yes it is absolutely possible to make an IPsec tunnel with MAP's and access lists, that supports IPv6. Link to complete guide:


I'm not sure on the last question. But i think it must be possible. I don't have equiptment available to check the commands available myself. You've not stated what kind of equipment you are using.

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