.
The company must subscribe to an external WAN service provider.
The company has direct control over its WAN links but not over its LAN.
Each LAN has a specified demarcation point to clearly separate access layer and distribution layer equipment.
The LAN may use a number of different network access layer standards whereas the WAN will use only one standard.
When its employees become distributed across many branch locations
When the network will span multiple buildings
When the number of employees exceeds the capacity of the LAN
When the enterprise decides to secure its corporate LAN
Network layer
Session layer
Physical layer
Transport layer
Data link layer
Presentation layer
Cable
Frame Relay
DSL
ATM
Cellular
PSTN
DSL
MPLS
T1/E1
VPN
3G/4G cellular
Dialup
VSAT
WiMAX
ISDN
DSL
Dialup
Cable
Dial-up connection
Leased line connection
Site-to-site VPN over the Internet
Remote access VPN over the Internet
2
12
24
28
Interface reset
Unplugged cable
Improper cable type
PPP issue
Ethernet
PPPoE
HDLC
PPP
PPP can use synchronous and asynchronous circuits.
PPP can only be used between two Cisco devices.
PPP carries packets from several network layer protocols in LCPs.
PPP uses LCPs to establish, configure, and test the data-link connection.
PPP uses LCPs to agree on format options such as authentication, compression, and error detection.
The PPP link will be closed down if the link quality drops below 70 percent.
The NCP will send a message to the sending device if the link usage reaches 70 percent.
The LCP establishment phase will not start until the bandwidth reaches 70 percent or more.
The PPP link will not be established if more than 30 percent of options cannot be accepted.
Establishes identities with a two-way handshake
Uses a three-way authentication periodically during the session to reconfirm identities
Control by the remote host of the frequency and timing of login events
Transmits login information in encrypted format
Uses an unpredictable variable challenge value to prevent playback attacks
Makes authorized network administrator intervention a requirement to establish each session
LTE
GSM
CDMA
UMTS
Satellite
DSL
WiMax
Cable
PAP
CHAP
HDLC
Frame Relay
Application Network Profile
Application Policy Infrastructure Controller
Cisco Nexus Switches
Microsoft hypervisor
Cisco Information Server
Virtual Security Gateway
The VPN connection is not statically defined.
VPN client software is installed on each host.
Internal hosts send normal, unencapsulated packets.
Individual hosts can enable and disable the VPN connection.
Creates nonsecure tunnels between remote sites*
Transports multiple Layer 3 protocols
Creates additional packet overhead
Uses RSA signatures to authenticate peeers
Provides encryption to keep VPN traffic confidential
Supports hosts as GRE tunnel endpoints by installing Cisco VPN client software
R1(config-if)# tunnel source 209.165.202.129
R1(config-if)# tunnel source 172.16.2.1
R1(config-if)# tunnel destination 206.165.202.130
R1(config-if)# tunnel destination 172.16.2.2
R1(config-if)# tunnel source 209.165.202.130
R1(config-if)# tunnel destination 206.165.202.129
TCP connections
Area numbers
Group identification numbers
Hellos
Access-list 105 permit ip host 10.0.70.23 host 10.0.54.5 access-list 105 permit tcp any host 10.0.54.5 eq www access-list 105 permit ip any any
Access-list 105 permit tcp host 10.0.54.5 any eq www access-list 105 permit tcp host 10.0.70.23 host 10.0.54.5 eq 20 access-list 105 permit tcp host 10.0.70.23 host 10.0.54.5 eq 21
Access-list 105 permit tcp host 10.0.70.23 host 10.0.54.5 eq 20 access-list 105 permit tcp host 10.0.70.23 host 10.0.54.5 eq 21 access-list 105 permit tcp 10.0.0.0 0.255.255.255 host 10.0.54.5 eq www access-list 105 deny ip any host 10.0.54.5 access-list 105 permit ip any any
R2(config)# interface gi0/0 R2(config-if)# ip access-group 105 in
R1(config)# interface gi0/0 R1(config-if)# ip access-group 105 out
R1(config)# interface s0/0/0 R1(config-if)# ip access-group 105 out
Manually add the new deny statement with a sequence number of 5.
Manually add the new deny statement with a sequence number of 15.
Create a second access list denying the host and apply it to the same interface.
Add a deny any any statement to access-list 1.
The ACL is missing the deny ip any any ACE.
Because there are no matches for line 10, the ACL is not working.
The ACL is only monitoring traffic destined for 10.23.77.101 from three specific hosts.
The router has not had any Telnet packets from 10.35.80.22 that are destined for 10.23.77.101.