CCNA Questions/Answers IPv6. Select the valid IPv6 address from given ones. (Choose two) A. FE63::0043::11:21 B :2:11.1 C.

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1 Select the valid IPv6 address from given ones. (Choose two) A. FE63::0043::11:21 B :2:11.1 C. 2001::98 D. 2002:c0a8:101::42 E. :2001:: F cb0a:3cdd:1::1 Answer: C, D

2 Which method is used to pass IPv6 traffic through IPv4 network? A. NAT overload B. NAT-PT C. Dual stack D. 6to4 tunneling Answer: D "6to4 tunneling" is an IPv6 transition mechanism described in RFC Like many other transition mechanisms, it enables encapsulation of IPv6 packets into IPv4 for transport across an IPv4 network. 6to4 allows for automatic IPv6-to-IPv4 address translation, and treats the underlying IPv4 network as one big non-broadcast multiaccess (NBMA) network, rather than a collection of independent point-to-point links. IPv6 NAT-PT is to be used with IPv4 to IPv6 migration scenarios and its purpose is to provide bidirectional connectivity between IPv4 and IPv6 domains. NAT Overload is the most common NAT method used throughout all networks that connect to the Internet. NAT overload sometimes called PAT (Port Address Translation) maps multiple unregistered or private IP addresses to a single registered or public IP address by using different ports. This is what most home broadband routers do. Your ISP assigns an IP address to your router, but you find out that all the computers in the house could connect to the Internet at the same time. PAT uses unique source port numbers on the inside global IP address to distinguish between translations. Dual stack, involves running IPv4 and IPv6 at the same time. End nodes and routers/switches run both protocols, and if IPv6 communication is possible that is the preferred protocol. A common dual-stack migration strategy is to make the transition from the core to the edge. This involves enabling two TCP/IP protocol stacks on the WAN core routers, then perimeter routers and firewalls, then the server-farm routers and finally the desktop access routers. After the network supports IPv6 and IPv4 protocols, the process will enable dual protocol stacks on the servers and then the edge computer systems

3 What is the IPv6 loopback address? A. ::1 B. ::2 C. fc11:: D. 1111:1111:: Answer: A ::1/128 The loopback address is a unicast localhost address. If an application in a host sends packets to this address, the IPv6 stack will loop these packets back on the same virtual interface (same as /8 in IPv4). Loopback address is used for local testing of the interface and protocol stack. Routers will not forward packets that source or destination address is loopback address

4 Select the term from the left and associate with definition from the right. Some items can be used more than ones. Answer: ; Link

5 What DUAL stack networks can offer to the end-user host? A. To pass IPv4 traffic on only IPv6 network. B. To pass IPv6 traffic on only IPv4 network. C. Address translation between LAN and Internet. D. To send IPv4 and IPv6 traffic. Answer: D When a device has dual stack capabilities then it has access to both IPv4 and IPv6 technology available. It can use both of these technologies to connect to remote servers and destinations in parallel. When a client wants to connect to a server (e.g., the client issues two DNS requests in parallel: one request for IPv4 addresses, and one request for IPv6 addresses. After receiving the responses, the client generally follows the process described in IETF standard RFC3484 Default Address Selection for IPv6 which leans towards an assumption that dual stack is a state of transitioning towards and IPv6-only network, and hence prefers IPv6 above IPv4 by design. When a client receives a response including both an IPv4 and IPv6 address then based upon RFC3484 the IPv6 address is the preferred address. If, for whatever reason, the usage of that address was nonsuccessful, an alternate address will be used, potentially a valid IPv4 address to connect to the remote location. It is possible for a dual stack device to connect to an IPv4-only or IPv6-only device. The protocol selected, IPv4 or IPv6 is based upon the IP addresses received within a DNS response. If the DNS server returned only IPv4 addresses, then IPv4 is used, if the DNS server returned only IPv6 addresses then IPv6 is used. There are two elements with respect to DNS. The first is related to the protocol the DNS client is using to speak to the DNS server, which could be IPv4 or IPv6 based. Most DNS servers support both IPv4 and IPv6 initiated requests. Another element is related towards IP addresses being transferred within the DNS resource request. The addresses returned as response can either be an IPv4 address or IPv6 address. It is up to the client to decide which address it will use to connect to the remote Internet resource (i.e

6 How many double colons can exist in IPv6 address? A. One example: 2607:f0d0:1002:51::4 B. Two - example: 2607::f0d0:1002:51::4 C. Four - example: 2607::f0d0::1002::51::4 D. Eight - example: 2607::f0d0::10::02::51::4::78::11::9 Answer: A Internet Protocol Version 6 (IPv6) is a version of the Internet Protocol which is designed to succeed Internet Protocol version 4 (IPv4). IPv6 addresses are 128 bits long and are written groups of four hexadecimal digits separated by colons. In short IPv6 addresses are divided into two parts: a 64-bit network prefix, and a 64-bit interface identifier. IPv6 addresses are classified as follows: 1. Unicast addresses - used to identify each network interface. 2. Anycast addresses - used to identify a group of interfaces at different locations. 3. Multicast addresses - used to deliver one packet to many interfaces. IPv6 does not support the broadcast method. ; Link

7 Running both IPv4 and IPv6 on a router simultaneously is known as what? A. 4to6 routing B. 6to4 routing C. binary routing D. dual-stack routing E. NextGen routing Answer: D One technique for transitioning to IPv6 is by using dual IPv4 and IPv6 protocol stacks. Using dual stacks enables gradual, one-by-one upgrades to applications running on nodes. Applications that are upgraded to IPv6 use the IPv6 protocol stack, and applications that are not upgraded and support only IPv4 can coexist with upgraded applications on the same node. New and upgraded applications can use both IPv4 and IPv6 protocol stacks. This approach is described in RFC

8 What are three IPv6 transition mechanisms? (Choose three.) A. 6to4 tunneling B. VPN tunneling C. GRE tunneling D. ISATAP tunneling E. PPP tunneling F. Teredo tunneling Answer: A, D, F ; Link2; Link

9 Which two of these statements are true of IPv6 address representation? (Choose two) A. A single interface may be assigned multiple IPv6 addresses of any type. B. Every IPv6 interface contains at least one loopback address. C. Leading zeros in an IPV6 16 bit hexadecimal field are mandatory. D. The first 64 bits represent the dynamically created interface ID. Answer: A, B As per RFC 4291, a single interface of a router can be configured with multiple IPv6 addresses. All Cisco IOS release with IPv6 support, a router interface can be configured with multiple IPv6 global addresses within the same prefix. Every IPv6-enabled interface must contain at least one loopback and one link-local address. ; Link

10 Which two are correct about IPv6 addressing? A. 2000::/3 is a global unicast address. B. there is only one loopback address ::1. C. FF00::/ is the Link-local address. D. FE00::/ is the unique-local address. Answer: A, B