Chapter 14: IPv6
33-33-FF-17-FC-0F
2. What is the corresponding Ethernet address for FF02:0000:0000:0000:0000:0001:FF17:FC0F?
d
2. Which of the following are advantages of using NAT? (Choose three.) A. Translation introduces switching path delays. B. NAT conserves legally registered addresses. C. NAT causes loss of end-to-end IP traceability. D. NAT increases flexibility when connecting to the Internet. E. Certain applications will not function with NAT enabled. F. NAT remedies address overlap occurrence.
c
20. Which of the following needs to be added to the configuration to enable PAT? ip nat pool Corp 198.18.41.129 198.18.41.134 netmask 255.255.255.248 access-list 1 permit 192.168.76.64 0.0.0.31 A. ip nat pool inside overload B. ip nat inside source list 1 pool Corp overload C. ip nat pool outside overload D. ip nat pool Corp 198.41.129 net 255.255.255.0 overload
a, b, c
3. Which command will allow you to see real-time translations on your router? A. show ip nat translations B. show ip nat statistics C. debug ip nat D. clear ip nat translations *
Link-local
3. Which type of address is not meant to be routed?
2001:0DB8::/32
Also reserved for examples and documentation
128
An IPv6 address is actually ___ bits in length
four, field, eight, colons
There are ___ hexadecimal characters (16 bits) in each IPv6 ___ (with ___ fields total), separated by ___.
d
1. Which of the following are disadvantages of using NAT? (Choose three.) A. Translation introduces switching path delays. B. NAT conserves legally registered addresses. C. NAT causes loss of end-to-end IP traceability. D. NAT increases flexibility when connecting to the Internet. E. Certain applications will not function with NAT enabled. F. NAT reduces address overlap occurrence.
128 and 129
1. Which two ICMPv6 types are used for testing IPv6 reachability?
FF02::2
10. Which IPv6 address is the all-router multicast group?
c
10. Which of the following would be a good starting point for troubleshooting if your router is not translating? A. Reboot. B. Call Cisco. C. Check your interfaces for the correct configuration. D. Run the debug all command
10101000, A8
10101010 represents the first 8 bits of the MAC address (aa), which when inverting the 7th bit becomes ________. The answer becomes ___. I can't tell you how important this is for you to understand, so bear with me and work through a couple more!
a, e
11. Which of the following would be good reasons to run NAT? (Choose three.) A. You need to connect to the Internet and your hosts don't have globally unique IP addresses. B. You change to a new ISP that requires you to renumber your network. C. You don't want any hosts connecting to the Internet. D. You require two intranets with duplicate addresses to merge.
a
12. Which of the following is considered to be the inside host's address after translation? A. Inside local B. Outside local C. Inside global D. Outside global
b
13. Which of the following is considered to be the inside host's address before translation? A. Inside local B. Outside local C. Inside global D. Outside global
b, d
14. By looking at the following output, determine which of the following commands would allow dynamic translations? Router#show ip nat trans Pro Inside global Inside local Outside local Outside global --- 1.1.128.1 10.1.1.1 --- --- --- 1.1.130.178 10.1.1.2 --- --- --- 1.1.129.174 10.1.1.10 --- --- --- 1.1.130.101 10.1.1.89 --- --- --- 1.1.134.169 10.1.1.100 --- --- --- 1.1.135.174 10.1.1.200 --- --- A. ip nat inside source pool todd 1.1.128.1 1.1.135.254 prefix-length 19 B. ip nat pool todd 1.1.128.1 1.1.135.254 prefix-length 19 C. ip nat pool todd 1.1.128.1 1.1.135.254 prefix-length 18 D. ip nat pool todd 1.1.128.1 1.1.135.254 prefix-length 21
a, b, c
15. Your inside locals are not being translated to the inside global addresses. Which of the following commands will show you if your inside globals are allowed to use the NAT pool? ip nat pool Corp 198.18.41.129 198.18.41.134 netmask 255.255.255.248 ip nat inside source list 100 int s0/0 Corp overload A. debug ip nat B. show access-list C. show ip nat translation D. show ip nat statistics
b
16. Which command would you place on the interface of a private network? A. ip nat inside B. ip nat outside C. ip outside global D. ip inside local
d
17. Which command would you place on an interface connected to the Internet? A. ip nat inside B. ip nat outside C. ip outside global D. ip inside local
a, d
18. Port Address Translation is also called what? A. NAT Fast B. NAT Static C. NAT Overload D. Overloading Static
b, c
19. What does the asterisk (*) represent in the following output? NAT*: s=172.16.2.2, d=192.168.2.1->10.1.1.1 [1] A. The packet was destined for a local interface on the router. B. The packet was translated and fast-switched to the destination. C. The packet attempted to be translated but failed. D. The packet was translated but there was no response from the remote host.
Link-local
4. What type of address is this: FE80::/10?
a, c, d
4. Which command will show you all the translations active on your router? A. show ip nat translations B. show ip nat statistics C. debug ip nat D. clear ip nat translations *
a, b
5. Which command will clear all the translations active on your router? A. show ip nat translations B. show ip nat statistics C. debug ip nat D. clear ip nat translations *
Multicast
5. Which type of address is meant to be delivered to multiple interfaces?
b, e, f
6. Which command will show you the summary of the NAT configuration? A. show ip nat translations B. show ip nat statistics C. debug ip nat D. clear ip nat translations *
Anycast
6. Which type of address identifies multiple interfaces, but packets are delivered only to the first address it finds?
c
7. Which command will create a dynamic pool named Todd that will provide you with 30 global addresses? A. ip nat pool Todd 171.16.10.65 171.16.10.94 net 255.255.255.240 B. ip nat pool Todd 171.16.10.65 171.16.10.94 net 255.255.255.224 C. ip nat pool todd 171.16.10.65 171.16.10.94 net 255.255.255.224 D. ip nat pool Todd 171.16.10.1 171.16.10.254 net 255.255.255.0
OSPFv3
7. Which routing protocol uses multicast address FF02::5?
::1
8. IPv4 had a loopback address of 127.0.0.1. What is the IPv6 loopback address?
b, c, e
8. Which of the following are methods of NAT? (Choose three.) A. Static B. IP NAT pool C. Dynamic D. NAT double-translation E. Overload
FE80::/10
9. What does a link-local address always start with?
a, d
9. When creating a pool of global addresses, which of the following can be used instead of the netmask command? A. / (slash notation) B. prefix-length C. no mask D. block-size
one
Anycast Like multicast addresses, an anycast address identifies multiple interfaces on multiple devices. But there's a big difference: the anycast packet is delivered to only ___ device—actually, to the closest one it finds defined in terms of routing distance. And again, this address is special because you can apply a single address to more than one host.
ipv6 address autoconfig
By using the command ___ ___ ___ the interface will listen for RAs and then, via the EUI-64 format, it will assign itself a global address—sweet!
0:0:0:0:0:0:0:0
Equals ::. This is the equivalent of IPv4's 0.0.0.0 and is typically the source address of a host before the host receives an IP address when you're using DHCP-driven stateful configuration.
0:0:0:0:0:0:0:1
Equals ::1. The equivalent of 127.0.0.1 in IPv4.
drop
First, you can ___ any leading zeros in each of the individual blocks.
fixed
For the objectives, remember that unlike IPv4 headers, IPv6 headers have a ___ length, use an extension header instead of the IPv4 Fragmentation field, and eliminate the IPv4 checksum field.
2000:/3, 48, 16, interface address, unique host ID
Global unicast addresses (_____) These are your typical publicly routable addresses and they're the same as in IPv4. Global addresses start at 2000::/3. Figure 14.2 shows how a unicast address breaks down. The ISP can provide you with a minimum /___ network ID, which in turn provides you ___-bits to create a unique 64-bit router ___ ___. The last 64-bits are the ___ ___ ___.
4.3 billion
IPv4 has only about ___ ___addresses available—in theory—and we know that we don't even get to use most of those!
128
IPv6 is ___ bits long
ipv6 unicast-routing
In order to enable IPv6 on a router, you have to use the ___ ___ ___ global configuration command:
1. 2001:db8:1:1:090c:abff:fecd:1234 2. 2001:db8:1:1:040c:32ff:fef1:a4d2 3. 2001:db8:1:1:12:abff:fecd:1234 4. 2001:db8:1:1:0f01:3aff:fe2f:1234 5. 2001:db8:1:1:080c:abff:feac:caba
In this section, you will practice inverting the 7th bit of a EUI-64 address. Use the prefix 2001:db8:1:1/64 for each address. 1. Convert the following MAC address into a EUI-64 address: 0b0c:abcd:1234. 2. Convert the following MAC address into a EUI-64 address: 060c:32f1:a4d2. 3. Convert the following MAC address into a EUI-64 address: 10bc:abcd:1234. 4. Convert the following MAC address into a EUI-64 address: 0d01:3a2f:1234. 5. Convert the following MAC address into a EUI-64 address: 0a0c.abac.caba.
FE80::/10
Link-local addresses (______) These are like the Automatic Private IP Address (APIPA) addresses that Microsoft uses to automatically provide addresses in IPv4 in that they're not meant to be routed.
FC00::/7
The unique local unicast range.
FF00::/8
Multicast (______) Again, as in IPv4, packets addressed to a multicast address are delivered to all interfaces tuned into the multicast address. Sometimes people call them "one-to-many" addresses.
subnet
Remember, if you have only a link-local address, you will be able to communicate only on that local ___
MAC
Remember, the EUI-64 (extended unique identifier) format allows the device to use its MAC address and pad it to make the interface ID. Check it out: Corp(config-if)#ipv6 address 2001:db8:3c4d:1::/64 eui-64
3FFF:FFFF::/32
Reserved for examples and documentation
consecutive zeros
Rule 1: Eliminate groups of ___ ___
leading zeros
Rule 2: Drop ___ ___o
FFFE
Since the interface ID in an IPv6 address is 64 bits in length and a MAC address is only 48 bits, where do the extra 16 bits come from? The MAC address is padded in the middle with the extra bits—it's padded with ___.
ipv6 address autoconfig default
So basically, I want to have the Branch router work with IPv6 on the internetwork with the least amount of effort from me. Let's see if I can get away with that.
one
So if my address has four blocks of zeros and each of them were separated, I just don't get to replace them all because I can replace only ___ contiguous block with a doubled colon.
58
The ICMPv6 packet is identified by the value 58 in the Next Header field, located inside the ICMPv6 packet.
Global prefix
The ___ ___ is 48 bits long
interface ID
The ___ ___ is 64 bits long
Subnet
The ___ is 16 bits long
2000::/3
The global unicast address range.
FE80::/10
The link-local unicast range
FF00::/8
The multicast range
default
This is all really great, but you're hopefully wondering what that default is doing there at the end of the command. If so, good catch! It happens to be a wonderful, optional part of the command that smoothly delivers a default route received from the Corp router, which will be automatically injected into my routing table and set as the default route—so easy!
0:0:0:0:0:0:192.168.100.1
This is how an IPv4 address would be written in a mixed IPv6/IPv4 network environment.
ipv6 enable
To configure a router so that it uses only link-local addresses, use the ___ ___ interface configuration command:
8, 4
To make addresses more manageable, divideded into __ groups of __ hex characters
133, 134
To perform autoconfiguration, a host goes through a basic two-step process: 1. First, the host needs the prefix information, similar to the network portion of an IPv4 address, to configure its interface, so it sends a router solicitation (RS) request for it. This RS is then sent out as a multicast to all routers (FF02::2). The actual information being sent is a type of ICMP message, and like everything in networking, this ICMP message has a number that identifies it. The RS message is ICMP type ___. 2. The router answers back with the required prefix information via a router advertisement (RA). An RA message also happens to be a multicast packet that's sent to the all-nodes multicast address (FF02::1) and is ICMP type ___. RA messages are sent on a periodic basis, but the host sends the RS for an immediate response so it doesn't have to wait until the next scheduled RA to get what it needs.
single
Unicast Packets addressed to a unicast address are delivered to a ___ interface. For load balancing, multiple interfaces across several devices can use the same address, but we'll call that an anycast address.
FC00::/7
Unique local addresses (______) These addresses are also intended for nonrouting purposes over the Internet, but they are nearly globally unique, so it's unlikely you'll ever have one of them overlap.
2002::/16
Used with 6-to-4 tunneling, which is an IPv4-to IPv6 transition system. The structure allows IPv6 packets to be transmitted over an IPv4 network without the need to configure explicit tunnels.
dual stack
When you run IPv4 and IPv6 on a router, you have what is called "___ ___."
anycast, more than
___ communication allows the same address to be placed on ___ ___ one device so that when traffic is sent to the device service addressed in this way, it's routed to the nearest host that shares the same address.
anycast
one-to-closest
multicast
one-to-many
Unicast
one-to-one
doubled colon
we can remove the two consecutive blocks of zeros by replacing them with a ___ ___