8.1 IPv6 Routing Overview - 8.3 EIGRPv6 Flashcards
Describe Unicast addressing Link-local addresses
addresses that are valid on only the current subnet–hosts and routers running IPv6 create link-local addresses for interfaces on the subnet. Protocols give packets that remain within the subnet link-local addressing.
Describe Unicast addressing Global addresses
-unique addresses similar to public addresses in IPv4. An organization is assigned a global unique address prefix by an ISP. Each entity within the organization uses this unique prefix.
Describe Unicast addressing Unique local unicast addressing
-similar to private addresses in IPv4. Organizations use unique local addressing to communicate within a site or between a limited number of sites.
Describe IPv6 DHCP
Stateless address autoconfiguration (SLAAC) automatically generates the interface ID and uses NDP to learn the subnet prefix, the prefix length, and the default gateway. This method builds the host’s IPv6 address on the host without network messages and learns DNS server addressing using stateless DHCPv6 from a DHCP6 server.
How do you enable IPv6 config
To enable IPv6 using the global command, use ipv6 unicast-routing.
To enable IPv6 on each interface, use the ipv6 address address/length command.
ipv6 uni-cast routing
Used to enable IPv6 routing on Cisco routers.
ipv6 address
Used to enable IPv6 on each interface and configure the interface address and prefix. Use this command only on interfaces that will be in use.
ipv6 route [route address] [exit interface]
Statically adds IPv6 routes to the routing table.
What are the three areas you need to consider when troubleshooting IPv6
host configuration issues, switch-related issues, and router-related issues.
Diag problem Between hosts and routers
Mismatched subnets between hosts and the default router.
Duplicate subnets.
Mismatched prefix lengths between hosts and the default router.
Incorrect router address in the default router setting.
Incorrect DNS server addresses.
Diag problem Router-specifi
A router interface in a down state.
Mismatched addresses for routers on the same subnet.
Routers without a route to a subnet.
Incorrectly configured static routes.
Mismatched routing protocols between neighbors.
Diag problem Filters
Inadvertent filtering of a MAC address.
A filter that prevents the route from being added to the routing table.
VLANs not on the switches.
ACLs incorrectly configured.
Troubleshooting tips for IPv6
Cisco routers support ping, traceroute, and their extended versions for IPv6.
Use show ipv6 route to display the route an IPv6 router would use to send packets to a specified destination address.
Use show ipv6 neighbors to list the IPv6 replacement for the IPv4 ARP table.
A failed ping from a host to the default router might indicate:
A router or host interface is administratively disabled.
The network has problems that prevent the flow and/or delivery of packets.
Filtering is preventing the flow and/or delivery of packets.
router(config)#ipv6 router ospf [process id]
Enables OSPF for IPv6 router configuration.
router(config-rtr)#router-id [a.b.c.d]
Configures the IPv6 router ID for the specified routing process. Configuring the router ID is recommended. The router ID can also be set by:
Configuring an IP address on a loopback interface.
Allowing the system to designate the interface IP address.
If an IPv4 address is not configured on any interface, you must use the router-id command to configure a router ID before the OSPF process will be started.
