EVE ACL Challenge

EVE Starting Topology

Reflections from the unit coordinator... Discuss these with your instructor if you have problems in these areas and take these thoughts into account as you work through the lab.

• ACLs applied to loopbacks do not work as the concept of IN/OUT makes no sense. Student should apply ACL to physical router interfaces or VTY only.
• Give consideration to removing the loopback and replacing it with an ISP router. That would fit better with the case study as well.
• Depending on the errors made, many students will break OSPF communications and thus all communications fail. It's a good learning experience but only if they eventually figure out what has happened. Many students assume the lack of communications is because the ACL is blocking their packets. In reality the router has no route because OSPF is down.
• Virtual PCs produce meaningful outputs but there should be some example output showing Telnet success, failure and route unavailable.

Basic ACLs Starting Topology

Topology

Addressing Table

Device         Interface          IP Address        Subnet Mask         Default Gateway
                 e0/0            192.168.10.1       255.255.255.0 
R1               e0/1            192.168.11.1       255.255.255.0
                 s2/0            10.1.1.1           255.255.255.252

                 s2/0            10.1.1.2           255.255.255.252
R2               s2/1            10.2.2.1           255.255.255.252
                 Lo0             209.165.200.225    255.255.255.224

                 e0/1            192.168.30.1       255.255.255.0
R3               s2/1            10.2.2.2           255.255.255.252
 
PC1              NIC             192.168.10.10      255.255.255.0        192.168.10.1

PC2              NIC             192.168.11.10      255.255.255.0        192.168.11.1

PC3              NIC             192.168.30.10      255.255.255.0        192.168.30.1

Learning Objectives

• With reference to the Basic ACL Lab design and configure your own rules.

Preparation

• Run the EVE Topology and copy & paste the following configurations into the appropriate router and PC.

• Load the PC IP configurations with:

PC1

ip 192.168.10.10/24 192.168.10.1

PC2

ip 192.168.11.10/24 192.168.11.1

PC3

ip 192.168.30.10/24 192.168.30.1

• Ensure that there is end-to-end connectivity with the ping command.

Initial Router Configurations

hostname R1 interface Ethernet0/0

no shutdown
ip address 192.168.10.1 255.255.255.0

! interface Ethernet0/1

no shutdown
ip address 192.168.11.1 255.255.255.0

! interface Serial2/0

no shutdown
ip address 10.1.1.1 255.255.255.252
serial restart-delay 0

! router ospf 1

network 10.1.1.0 0.0.0.3 area 0
network 192.168.10.0 0.0.0.255 area 0
network 192.168.11.0 0.0.0.255 area 0

! line con 0

logging synchronous

line aux 0 line vty 0 4

password cisco
login
transport input telnet

! ! end

R2

hostname R2
!
!
interface Loopback0
 ip address 209.165.200.225 255.255.255.224
!
interface Serial2/0
 ip address 10.1.1.2 255.255.255.252
 serial restart-delay 0
 no shutdown
!
interface Serial2/1
 ip address 10.2.2.1 255.255.255.252
 serial restart-delay 0
 no shutdown
!
router ospf 1
 network 10.1.1.0 0.0.0.3 area 0
 network 10.2.2.0 0.0.0.3 area 0
 network 209.165.200.224 0.0.0.31 area 0
!
ip forward-protocol nd
!
!
no ip http server
no ip http secure-server
!
!
line con 0
 logging synchronous
line aux 0
line vty 0 4
 password cisco
 login
 transport input telnet
!
!
end

R3

hostname R3
!
!
interface Ethernet0/0
 no ip address
 shutdown 
!
interface Ethernet0/1
 ip address 192.168.30.1 255.255.255.0
 no shutdown
!
interface Serial2/1
 ip address 10.2.2.2 255.255.255.252
 serial restart-delay 0
 no shutdown
!
router ospf 1
 network 10.2.2.0 0.0.0.3 area 0
 network 192.168.30.0 0.0.0.255 area 0
!
ip forward-protocol nd
!
!
no ip http server
no ip http secure-server
!
line con 0
 logging synchronous
line aux 0
line vty 0 4
 password cisco
 login
 transport input telnet
!
!
end

Security Policies

Note: * * * Don't apply ACLs to the Loopback - They are special interfaces and IN/OUT are meaningless * * *

Policy 1

No users on the 192.168.10.0 /24 network may send packets to the R2 address 10.1.1.2

• Design an appropriate ACL, apply and test it.
• Consider:
  • Standard or Extended ACL?
  • Where is it best applied.

There may be multiple answers depending on your assumptions. Discuss the options and your thoughts with your peers or the tutor.

Policy 2

Only users on the 192.168.11.0 /24 network may Telnet to 209.165.200.225

• Design an appropriate ACL, apply and test it.
• Consider:
  • Standard or Extended ACL?
  • Where is it best applied.
  • This can be achieved with "access-groups" and "access-classes". Use either method but understand both.
  • Careful to distinguish between IP and TCP.

There may be multiple answers depending on your assumptions. Discuss the options and your thoughts with your peers or the tutor.

Note that in EVE the Virtual PCs support a "ping" command that can be used to test TCP and UDP ports. To see the options try:

PC2> ping help

To test Telnet (port 23) connectivity to 209.165.200.225:

PC2> ping 209.165.200.225 -3 -p 23

Policy 3

Users on IP addresses between 192.168.30.32 and 192.168.30.40 may not ping the Internet Loopback address

• Design an appropriate ACL, apply and test it.
• Consider:
  • Standard or Extended ACL?
  • Where is it best applied.
  • Remember the "implicit deny"

There may be multiple answers depending on your assumptions. Discuss the options and your thoughts with your peers or the tutor.