External Router Flashcards
What device is used to forward data between networks and block networks, subnets, and specific IP addresses?
Router
Which basic router command displays a list of all commands available?
?
Which basic router command can be put in front of any command to undo it?
no
Which basic router command displays the current routing table?
Router # show ip route
Which basic router command tests connectivity to an IP address?
Router # ping x.x.x.x
Which basic router command switches to configuration mode?
Router # config t
Which basic router command shows layer 3 interface information such as applied access-lists?
Router # show ip interface
Which basic router command creates a standard ACL?
Router(config)# ip access-list standard 1
Which basic router command creates a standard ACL entry to permit or deny a source IP address or range?
Router(config-std-nacl)# {permit | deny} src_ip wildcard_mask
Which basic router command creates an extended ACL?
Router(config)# ip access-list extended 101
What is used to identify the network a device belongs to and contains a series of leftmost contiguous “1” bits used to identify the network portion of an IP address?
Subnet Mask
What is used to identify the network a device belongs to and contains a series of the leftmost contiguous “0” bits used to match the network portion of the IP address?
Wildcard Mask (or Reverse Mask)
(T/F) Standard ACLs are concerned with the source IP address of the packet; the destination is not considered.
True
Which standard ACL command drops all packets that match the specified source address?
Deny
Which standard ACL command allows packets that match the specified source address to flow through the interface?
Permit
Whitelisting relies on using which ACL command?
Permit
Blacklisting relies on using which ACL command?
Deny
Which standard ACL keyword specifies any host? This is the same as using an IP address and wildcard mask of 255.255.255.255
Any
Which standard ACL keyword specifies an exact host match? This is the same as specifying a wildcard mask of 0.0.0.0
Host
Extended ACLs filter packets based on a combination of what?
- Source IP address, network, or port
- Destination IP address, network, or port
- Protocol type (TCP, UDP, ICMP, EIGRP, OSPF, etc.)
Which extended ACL command allows or drops all packets that match the specified destination IP address?
Destination
Which extended ACL command matches the network portion of the destination IP address?
Destination-wildcard
Which extended ACL command matches the port in TCP or UDP?
Destination-port
Which extended ACL command verifies whether either the RST or ACK bit is set. If either of these bits is set, the packet is part of a previously established connection. This can be used to restrict TCP responses to one direction when sessions are initiated from the opposite direction.
Established (TCP only)
