Day 17 - The Routing Table Flashcards
Routers use what to determine the best path?
Routing tables
What are the two primary functions of a router?
Determine the best path for forwarding packets
Forward packets to their destinations
The best path in the routing table is also known as what?
The longest match
The router uses the __________ __________ __________ to find a match between the destination IP address of the packet and a routing entry in the routing table
Longest match process
The route with the greatest number of equivalent __________ __________ __________, or the __________ __________ is always the preferred route
Far left bits
Longest match
For a destination IPv4 address of 172.16.0.10 what would be the preferred route from the choices below?
A: 172.16.0.0/12
B: 172.16.0.0/16
C: 172.16.0.0/26
C
It has the longest match
For an IPv6 destination address of 2001:db8:c000::99, what would be the preferred route from the choices below?
A: 2001:db8:c000::/40
B: 2001:db8:c000::/48
C: 2001:db8:c000:5555::/64
B
the subet hextet (5555) doesn’t match the IPv6 destination address at all
/48 is the longest match here
After a router has determined the best path based on the longest match in the routing table, what 3 things can it do?
Forward the packet to a device on a directly connected network
Forward the packet to the next hop router
Drop the packet because there is no match in the routing table
What is the primary responsibility of the packet forwarding function?
To encapsulate packets in the appropriate data link frame type for the outgoing interface
The routing table contains a list of all known network addresses (prefixes) and where to forward the packet. The entries are known as what?
Route entries or routes
What 3 types of routing entries does a routing table store?
Directly connected networks
Remote networks
Default routes
The __________ __________ is used when there is no better (longer) match in the IP routing table
Default route
What is the command to view an IPv4 routing table?
show ip route
What is the command to view an IPv6 routing table?
show ipv6 route
What type of routing table entry is below based on the letter in the routing table?
L
Directly connected local interface IP address
Based on the routing table below what does 1 represent?
Route source
Based on the routing table below what does 2 represent?
Destination network (prefix and prefix length)
Based on the routing table below what does 3 represent?
Administrative distance
Based on the routing table below what does 4 represent?
Metric
Based on the routing table below what does 5 represent?
Next hop address
Based on the routing table below what does 6 represent?
Route timestamp
Based on the routing table below what does 1 represent?
Route source
Based on the routing table below what does 7 represent?
Egress interface used for outgoing packets to reach their final destination
Based on the routing table below what does 2 represent?
Destination network (prefix and prefix length)
Based on the routing table below what does 3 represent?
Administrative distance
Based on the routing table below what does 4 represent?
Metric
Based on the routing table below what does 5 represent?
Next hop address
Based on the routing table below what does 7 represent?
Exit interface (egress interface for outgoing packets)
