Term
| How does IPv6 host learn its addresses when using Stateless Autoconfig? |
|
Definition
1) Host generates link-local address (FE:80:: + EUI-64)
2) Host sends Neighbor Solicitation to solicited node multicast address (FF02::1::ff + last 24 bits of mcast address)
3) Host sends router solicitation (RS) to FF02::2 (all routers) to get global prefix, etc. |
|
|
Term
| How does IPv6 host learn its addresses when using Stateful Autoconfig? |
|
Definition
1) Router Advertisement (RA) has M-bit set
2) Host sends DHCP request to FF02::1:2 or FF02::1:3, UDP port 547
3) DHCP server assigns full 128-bit address. |
|
|
Term
| What are multicast scopes and how are the indicated in IPv6 addresses? |
|
Definition
Mcast address format : FF.[4 bits lifetime][4 bits scope]
Scope bits are as follows:
Node -- 0001
Link -- 0010
Site -- 0101
Org -- 1000
Global -- 1110
Example: FF02 -- permanent lifetime, link scope |
|
|
Term
| What is the EUI-64 address for a device with the MAC address 0000.0c0a.2c51? |
|
Definition
0000.0c0a.2c51
->
0200:0cff:fe0a:2c51
(flip universal local bit, insert fffe after MAC OUI) |
|
|
Term
| For global unicast addresses, how many bits are available for an organization's subnets (site-level aggregator bits)? |
|
Definition
16 bits
|
|
45 bits
|
16 bits
|
64 bits
|
|
001
|
Global Routing Prefix
|
Site Level Aggregator
|
EUI-64
|
|
|
|
Term
| How often are Router Advertisements sent? |
|
Definition
|
|
Term
| What is the link-local address? |
|
Definition
| FE80::/10 + EUI-64 address |
|
|
Term
| How is an embedded RP indicated in a multicast packet? |
|
Definition
| Multicast address begins with FF7::/12 |
|
|
Term
| What IPv6 addresses does a host need to know? |
|
Definition
Link-local
Assigned unicast
Loopback address
All-nodes multicast (FF02::1)
Solicited node multicast for all unicast and anycast addresses.
Multicast address of all groups to which host belongs. |
|
|
Term
| What is the solicited-node multicast-address? What is it used for? |
|
Definition
FF02::1:F + last 24 bits of IPv6 address/104
Used for Neighbor discovery using the Neighbor Solicitation message. |
|
|
Term
| What is the MLD equivalent of an IGMP Leave? |
|
Definition
|
|
Term
| What is the MAC address of an IPv6 multicast packet? |
|
Definition
| 33-33 + last 32 bits of multicast address |
|
|
Term
| What is Neighbor Solicitation used for? |
|
Definition
Duplicate Address Detection
Learning Link-Layer Addresses
Determine if Neighbor is reachable |
|
|
Term
True or False:
ICMPv6 packets must be rate-limited |
|
Definition
True.
Default is 100 msec error-interval with token bucket size of 10 (1 token = 1 ICMPv6 message) |
|
|
Term
|
Definition
| FF02::1 = well known multicast address for all nodes |
|
|
Term
| What is the v6 multicast address for an OSPF speaker? |
|
Definition
|
|
Term
| What is the v6 multicast address for OSPF DR/BDR? |
|
Definition
|
|
Term
| What is FF02::A used for? |
|
Definition
|
|
Term
|
Definition
|
|
Term
| What is the MAC address of an IPv6 multicast packet to ff02::1:ff98:0? |
|
Definition
|
|
Term
| What is the function of the Traffic Class field in the v6 header? |
|
Definition
| Traffic class is the equivalent to IPv4 DSCP |
|
|
Term
| What 3 commands are needed to enable IPv6? |
|
Definition
ipv6 cef
ipv6 unicast-routing
interface e0
ipv6 enable |
|
|
Term
| What does a host do when it wants to join a IPv6 multicast group? |
|
Definition
| Host sends an MLD Report to group address. |
|
|
Term
| What is IGMP equivalent of MLD v1? |
|
Definition
MLD v1 => IGMPv2
MLD v2 => IGMPv3 |
|
|
Term
| What does an IPv6 multicast router do when it receives an MLD Done? |
|
Definition
| Router sends a multicast-address-specific Query to see if anyone else is interested. |
|
|
Term
| What multicast protocols does IPv6 support? |
|
Definition
|
|
Term
Why might you configure this:
ipv6 route ::/0 tunnel0 multicast |
|
Definition
| This is an IPv6 mroute that can help with RPF problems in tunnels. |
|
|
Term
| Name 3 functions ICMPv6 provides |
|
Definition
1) Error Reporting
2) MTU Path Discovery
3) Neighbor Discovery |
|
|
Term
| Name errors that ICMPv6 can report |
|
Definition
1) Packet too big
2) Hop Limit Exceeded
3) Bad Header
4) Unrecognized Option
5) No Route to Destination
6) Access Prohibited
7) Port Unreachable |
|
|
Term
| Is ICMPv6 rate-limited by default? |
|
Definition
| Yes, default is 100 ms error-interval with token bucket size of 10 tokens (ICMP messages) |
|
|
Term
| How often does a router send Router Advertisements by default and to what address? |
|
Definition
Every 200 seconds to FF02::1
In response RS, can be sent to unicast address. |
|
|
Term
| What provides the v6 equivalent of ARP? |
|
Definition
|
|
Term
Where is the following configured and what will happen to addresses that match the ACL?
ipv6 verify unicast reverse-path <ACL>
|
|
Definition
This is configured per-interface:
(config-if)#ipv6 verify unicast reverse-path <ACL>
Packets permitted by ACL will be exempt from uRPF checks. |
|
|
Term
| What are the 5 IPV6 neighbor reachability states? |
|
Definition
Incomplete (NS sent, no NA)
Reachable
Stale
Delay
Probe - send 3 @ 1 second, remove entry if no response |
|
|
Term
| What are AAAA records used for? |
|
Definition
|
|
Term
| What is the command to apply a v6 ACL to an interface? |
|
Definition
interface f0/0
ipv6 traffic-filter in |
|
|
Term
| How do you apply a v6 ACL to VTYs? |
|
Definition
line vty 0 4
access-class <v6 ACL> in |
|
|
Term
| What is the AD of a static route in IPv6? |
|
Definition
|
|
Term
| Where are Type 8 LSAs flooded? |
|
Definition
|
|
Term
| What LSA contains prefix information for the area in OSPFv6? |
|
Definition
| Type 9 (Intra-Area Prefix) LSA maps prefixes to Router LSAs and Network LSAs |
|
|
Term
| Is there a default v6 OSPF RID? |
|
Definition
| No, must have an IPv4 address on some interface OR explicitly configure RID. |
|
|
Term
| What authentication types are supported in OSPFv3? |
|
Definition
OSPFv3 relies on IPv6 mechanisms.
(config-if)#ipv6 ospf authentication -- AH
(config-if)#ipv6 ospf encryption -- ESP |
|
|
Term
| How are areas assigned in OSPFv3? |
|
Definition
On the interface:
interface E0
ipv6 enable
ipv6 ospf 100 area 0 |
|
|
Term
| If an OSPFv3 adjacency is not forming on a Frame Relay Link, what might be wrong? |
|
Definition
| OSPFv3 needs a FR map statement for the link local AND the unicast address |
|
|
Term
| What address is used for the "ADV Router" in OSPFv3? |
|
Definition
| ADV Router is the RID of the advertising router -- the v4-formatted RID! |
|
|
Term
| Can EIGRPv6 do classful routing? |
|
Definition
| No. no-auto-summary cannot be disabled in v6 EIGRP. |
|
|
Term
| Name 5 features that IPv6 QoS does not support. |
|
Definition
Not supported in IPv6:
NBAR
cRTP
CAR
PQ
CQ |
|
|
Term
| How do you do route filtering in EIGRP v 6? |
|
Definition
Distribute lists with prefix-lists:
ipv6 router eigrp 100
distribute-list prefix-list MYLIST in Serial1 |
|
|
Term
| What tunneling method would you use to connect isolated IPv6 islands over an IPv4 network? |
|
Definition
|
|
Term
| What is the reserved address space for 6to4 tunnels? |
|
Definition
|
|
Term
| How does a 6to4 tunnel know the IPv4 destination for a packet to 2002:c0a8:6501::1? |
|
Definition
| The IPv4 destination is extracted from the v6 address: 2002:c0a8:6501::1 -> c0a8:6501 -> 192.168.101.1 |
|
|
Term
| What tunnel type connects isolated v6 hosts in a single site? |
|
Definition
|
|
Term
What kind of address is the following? What do the last 4 octet represent?
2001:DB8:1234:5678:0000:5EFE:0AAD:8108 |
|
Definition
IPv6 ISATAP tunnel address.
0AAD:8108 = 10.173.129.8 = IPv4 address of this interface |
|
|
Term
| How are RAs handled in ISATAP tunnels? |
|
Definition
| RAs are suppressed by default in ISATAP tunnels. Enable them with "no ipv6 nd suppress-ra" |
|
|
Term
| What v6 tunnel types are point to multi-point? |
|
Definition
6to4 (inter-site)
ISATAP (intra-site) |
|
|
Term
| Why are 6to4 and ISATAP tunnels configured without a "tunnel destination"? |
|
Definition
| Because the v4 tunnel destination is derived dynamically for each packet (from the v6 address). |
|
|
Term
| How is the embedded IPv4 address different in 6to4 vs ISATAP? |
|
Definition
In 6to4, the IPv4 address comes right after 2002::/16 reserved prefix.
In ISATAP, the v4 address comes at the end of the v6 address, right after 0000:5EFE. |
|
|
Term
| Which address pool do v6 anycast addresses come from? |
|
Definition
|
|
Term
| What command limits the level of syslog messages sent to syslog servers? |
|
Definition
Router(config)# logging trap level
Limits the number of messages logged to the syslog servers.
(Logging trap is a trap because it makes you think SNMP when it's not). |
|
|
Term
| Which mechanism in IPv6 is responsible for Layer 3 to Layer 2 address resolution? |
|
Definition
| NDP (Neighbor Discovery Protocol) |
|
|
Term
| How many bits make up the Group ID in IPv6 multicast? |
|
Definition
|
|
Term
| What IPv6 header field can perform the same functions as the IPv4 protocol field? |
|
Definition
|
|
Term
| Name 4 QoS features that are supported with IPv6 |
|
Definition
MQC policing
MQC shaping
MQC marking
WRED |
|
|
Term
| How can you configure an IPv6 router with a higher preference when hosts get multiple RA responses? |
|
Definition
|
|
Term
| What 3 multicast addresses are joined when an interface is enabled for IPv6? |
|
Definition
All IPv6 nodes: FF02::1
All IPv6 routers: FF02::2
Solicited node: FF02::1:FF:: |
|
|
