IPv6 Addressing

Are Unique Local IPv6 addresses publicly reachable? What range are they assigned?

1. No 2. FC00::/7 Hosts should be assigned /64 addresses

1. Enable IPv6 routing 2. Assign IPv6 address 2001:db8:0:1::1 /64 on interface fa0/0

1. ipv6 unicast-routing 2. interface fa0/0 3. ipv6 add 2001:db8:0:1::1 /64

IPv6 address uses how many bits?

128

IPv6 uses how many fields for it's address?

16 bit hexidecimal in 8 different fields (hex values are 0-9, A-F)

If a company was assigned a /48 out of the address 2001:0010:0010:0000:0000:0000:0000 from Internet Authorities, and uses /64 for host addresses, how many bits can the company assign to its internal subnets? What is the range of subnets (use addressing shortening).

16 bits. 2001:10:10:0:: /64 to 2001:10:10:FFFF:: /64

If an interface has a MAC address of ca01.2f24.0000, what would it's IPv6 address be it it was generated using an EUI-64 address with a prefix of 2001:DB8:0:1 ?

2001:DB8:0:1:C801:2FFF:FE24:0 The FF:FE is injected in the middle of the 48-bit MAC address to make it 64 bits long.

What is the unspecificed address in IPv6?

:: An IPv6 route to ::/0 is a default route equivalent to 0.0.0.0 0.0.0.0 in IPv4 Also, :: is used as the source when an interface is trying to acquire an address.

What are some disadvantages of using SLAAC?

A DHCP Server is still required to give out information such as DNS server. If the IP address is aassigned by SLAAC and the DNS server is assigned by DHCP this results in a stateless configuration, where the DHCP server does not retain ifnormation about the hosts. SLAAC doesn't support additional information like DNS that DHCP issues out.

What are the three types of IPv6 addresses?

Global Unicast Unique Local Link Local

What IPv6 unicast address type has global reachability? What's the range?

Global Unicast Addresses 2000::/3

What is an EUI-64 Address?

Host portion of an IPv6 address derived from the interfaces's MAC address, which is guaranteed to be globally unique. A MAC address is a /48 address compared to the /64 host portion of the IPv6 address, so FF:FE is injected in the middle of the /48 MAC address to bring it up to 64 bits. Also, the 7th bit is inverted.

What is SLAAC? (Stateless Address AutoConfiguration)

Hosts can get IP address without using a DHCP server. Hosts learn the /64 subnet network portion their interface is on from their local router and then use this information to generate their own IPv6 EUI-64 address. Modern Operating Systems randomise the host portion of the address rather than using standard EUI-64 for privacy reasons The router does not track which hosts have which IP address so this is 'stateless' addressing.

Instead of using ARP requests and replies, what Neighbor Discovery use?

ICMP Neighbor Solicitations and Neighbor Advertisements Neighbor solicitation messages are sent to the solicited-node multicast address which reaches all hosts on the subnet

Which are addresses mandatory for? Global Unicast, Unique Local or Link Local?

Link Local

What is the IPv6 equivalent to IPv4's ARP?

Neighbor Discovery

What is dual stacking regarding IPv4 and IPv6?

Network interface can have both an IPv4 and an IPv6 address at the same time. I can communicate using either protocol. Dual stack can be enabled long term to suppor tboth IPv4 and IPv6 applications or as an IPv4 to IPv6 transition strategy.

Is IPv6 enabled my default?

No.

Does IPv6 support broadcast traffic?

No. It does however support multicast to all hosts on the local subnet which is functionally equivalent.

Is it recommended to use EUI-64 addresses on router interfaces?

No. It is better to use a memorable address such as 2001:db8:0:1::1 It makes them random and confusing. It is only useful for end-host.

How do you shorten an IPv6 address with a lot of zeros in it?

Remove the leading zeros in each field.

Can you use the same link local address on multiple interfaces?

Since they are valid on the local link only, they can use the same address on multiple interfaces.

What is a Link Local IPv4 IP address?

They can only communicate on the local link. Are assigned from the range FE80::/10 - FEB0::/10. Hosts should be assigned /64 addresses. These should be used for communications which should not be forwarded beyond the local link, like routing protocol hello packets and updates. They are mandatory on IPv6 enabled Cisco router interfaces. Link local is similar to APIPA for IPv4, but uses the EUI-64 feature, and for /64 bit host portion uses MAC address but inserts FFFE in the middle. Link Local is used by neighbor discovery protocol to find neighboring nodes on the same link segment.

Successive all zero fields can be shortened how? Can you do this more than once?

Using '::' 2001:DB8:0:1:0:0:0:1 can be written as 2001:DB8:0:1::1 Cannot do this more than once. 2001:0:0:1:0:0:0:B can be shortened to 2001::1:0:0:0:B or 2001:0:0:1::B It can't be shortened to 2001::1::B

Are EUI-64 Link Local addresses automatically generated?

Yes

Can you have multiple IP addresses on the same interface?

Yes. With IPv6, usually one link local address for routing protocol traffic and one global unicast address for normal routing is typical.

What address is used by IPv6 to support multicast to all hots on the local subnet?

ff02::1

In IPv6 what address is used for DHCP servers?

ff05::1:3

When you apply an IPv4 access list to an interface you use the ip access-group list in or out. What is the IPv6 equivalent; how would you apply an ipv6 access list to fa0/0 thats named F0/0_in?

interface fa0/0 ipv6 traffic-filter F0/0_in in

Configure global unicast EUI-64 IPv6 addresses on Fa0/0 using 2001:db8::/64

interface fa0/0 ipv6 2001.db8::/64

Configure an EUI-64 address on interface fa0/0 using prefix 2001:db8:0:1::/64

interface fa0/0 ipv6 address 2001:db8:0:1::/64 eui-64

Configure a manual link local address on F0/0 with last hextet being :1

interface fa0/0 ipv6 address fe80::1 link-local

Using IPv6, create an access list called F0/0_in permitting 2001:db8::10 telneting but no other device to telnet. Ensure there isn't an implicit deny at the bottom of ACL. Enable it on interface F0/0

ipv6 access-list F0/0_in permit tcp host 2001:db8::10 any eq telnet deny tcp any eq telnet permit ip any any exit interface f0/0 ipv6 traffic-filter F0/0_in in

What is the ipv4 equivalent to ip route 0.0.0.0 0.0.0.0 default route in ipv6?

ipv6 route ::/0

What is the equivalent of show iP interface brief for IPv6?

show ipv6 interface brief

How do you see the IPv6 neighbors on a router?

show ipv6 neighbors