Routing/Subnetting/IPv6/IPv4 Flashcards
what is a fully specified static route?
Both exit interface and next hop are specified:
- Destination network
- Exit interface
- Next hop IP address
what is a recursive static route?
what is it used for?
Only next hop is specified:
Used for default gateway.
-Destination Network
-Next hop IP address
(called recursive because it has to do two lookups, second one for next hop)
what is a floating static route?
Used for redundancy/failover if dynamic routing stops working, specifies:
- Destination Network
- Next hop IP address
- Administrative Distance
what is a directly attached static route?
Only exit interface is specified:
- Destination network
- Exit interface
What kind of IPv6 is this and what is it used for?
FD00:: /7
FC00:: /7
unique local
What kind of IPv6 is this and what is it used for?
FE80:: /10
link local
They are used for IPv6 routing protocols to form neighbor adjacencies.
automatically generated, uses eui-64
What kind of IPv6 is this and what is it used for?
2000:: /3
global unicast
internet routing
What kind of IPv6 is this and what is it used for?
FF01:: /8
FF0E:: /12
multicast
IPv6 routing protocols use what address type for establishing adjacency?
link-local
FE80:: /10
IPv6 multicast
FF02:: /8
FF00:: /12
IPv6 global unicast
2000:: /3
public address/internet routing
IPv6 link local
link local
FE80::/10
They are automatically generated on an interface when you enable IPv6 on an interface.
They are used for routing protocols to form neighbor adjacency, and NDP discovery.
How does IPv6 eui-64 conversion work?
Converts 48-bit MAC address into the 64-bit host portion of an 128-bit IPv6 address.
- Insert FF:FE in the middle
- Invert 7th bit (2nd digit from left)
Odd = Odd ±2
Even = Even ±2
(0 becomes 2, 2 becomes 0)
(1 becomes 3, 3 becomes 1)
unique local
FD00:: /7
(previously FC00:: /7)
-private IP address; no internet
-needs unique global ID in case of merge.
What is class D/multicast range?
224-239
What is class B range?
128-191
Inside Global
Public IP of the NATed host (post-NAT)
Inside Local
Private IP of the NATed host (pre-NAT)
Outside Local
The IP address the devices on the LAN see for the remote host (post-NAT)
Outside Global
The true IP address configured on the remote host by that host’s admin (pre-NAT)
documentation IPv6 address
2001:Db8:0 /64
What is automatically configured on an interface when enable IPv6?
link-local
FE80::/10
what command allows a router to use IPv6 routing?
(config)# ipv6 unicast-routing
How do you create an IPv6 static route?
ipv6 route 2000:2::/64 (next hop IP address)
How do you create an IPv6 floating static route?
ipv6 route 2000::/64 (ipv6-gateway-addr) distance 1
How do you create an EUI-64 address?
ipv6 address 2001:fc8:a52c:a::/64 eui-64
How do you create a modified EUI-64 address?
ipv6 address 2001:db8::/64 eui-64
just specify network prefix and add eui-64
What are the 3 parts of a global unicast?
48-bit (3 octet) global routing prefix assigned by ISP
16-bit (1 octet) subnet identifier for subnets
64-bit (4 octet) interface identifier for hosts
They are automatically generated on an interface when you enable IPv6 on an interface.
link-local
FE80::/10
What kind of address always uses EUI-64 rules for interface IDs?
link-local
FE80::/10
multicast address for “all routers”
FF00::2/8
244.0.0.2
multicast address for “OSPF routers”
FF00::5/8
224.0.0.5
multicast address for “OSPF DR/BDRs”
FF00::6/8
224.0.0.6
multicast address for “RIP routers”
FF00::9/8
224.0.0.9
multicast address for “EIGRP routers”
FF00::A/8
224.0.0.10
What are anycast addresses?
How do you configure one?
- useful for load balancing
- can specify a unique local or global unicast as an anycast address.
- Just add ‘anycast’ to end of command:
ipv6 address 2001::99/128 anycast
ID the 5 multicast scope types
FF01 - interface-local : can’t leave device.
FF02 - link-local multicast : can’t be routed.
FF05 - site-local : can be forwarded in a LAN.
FF08 - organization-local : can be forwarded in a WAN.
FF0E - global multicast : can be routed over internet.
NDP NS
FF02::1
ICMPv6 type 135
NDP NA
FF02::1
ICMPv6 type 136
NDP RS
FF02:2
ICMPv6 Type 133
NDP RA
FF02:1
ICMPv6 Type 134
What is SLAAC?
Stateless Address Auto-configuration
-Hosts use RS/RA messages to learn IPv6 prefix on local link and then automatically generate an ipv6 address.
What makes SLAAC different from eui-64?
SLAAC doesn’t need prefix to be entered, it learns it automatically from NDP.
How do you enable SLAAC?
ipv6 address autoconfig
What is DAD?
A function of NDP that prevents duplicate IPv6 addresses.
Uses NDP NS message
Syslog level 4.
Directly attached IPv6 routes have what problem?
They won’t work on an Ethernet interface, only serial.
Requires recursive or fully specified static route instead.
Required to use this type for link-local IPv6 next hops.
fully specified
the solicited-node multicast group
FF02::1
The solicited-nodes multicast group is required for link-layer address resolution.
the all nodes multicast group
FF02::1
The all- node group is used to communicate with all interfaces on the local link
the all-routers multicast group
FF02::2
172 range?
172.16.0.0 - 172.31.0.0
