VLAN ACLs

Question 1

What are VLAN ACLs used for?

Answer 1

Regulating intra-VLAN traffic on L3 switches.

Question 2

VLAN ACLs are not used for inter-VLAN traffic because this can be accomplished by what?

Answer 2

Regular or extended ACLs.

Question 3

What are the four steps in creating and applying a VLAN ACL?

Answer 3

1.Create an ACL. 2.Create a VLAN ACL, tie your ACL to it, and set your action. 3.Apply your VLAN ACL to a VLAN.

Question 4

What command will put you into VLAN ACL config mode?

Answer 4

vlan access-map _(name)_

Question 5

What happens if you do not specify an ACL to match in your VLAN ACL?

Answer 5

The VLAN ACL will apply to all traffic.

Question 6

What do you not have to specify on a VLAN ACL when applying it?

Answer 6

Whether to apply it to inbound/outbound.

Question 7

Refer to the exhibit. Which statement is true?

Router(config)# vlan access-map pass 10
Router(config-access-map)# match ip address ABC
Router(config- access-map)# action forward
Router(config)# vlan filter pass vlan-list 5-10
A. IP traffic matching access list ABC is forwarded through VLANs 5-10.
B. IP traffic matching VLAN list 5-10 will be forwarded, and all other traffic will be dropped.
C. All VLAN traffic matching VLAN list 5-10 will be forwarded, and all traffic matching access list ABC is dropped.
D. All VLAN traffic in VLANs 5-10 that match access list ABC will be forwarded, and all else will be dropped.

Answer 7

Answer: D

Explanation

Each VACL has an implicit “deny all” statement at the end, just like a regular ACL. From the exhibit we learn the VACL “pass” is applied from VLAN 5 to 10 with “action forward” -> All VLAN traffic in VLANs 5-10 that match ABC access list will be forwarded, other traffic in VLAN 5 to 10 will be dropped.

Question 8

VLAN maps have been configured on switch R1. Which of the following actions are taken in a VLAN map that does not contain a match clause?

A. Implicit deny feature at end of list.
B. Implicit deny feature at start of list.
C. Implicit forward feature at end of list
D. Implicit forward feature at start of list.

Answer 8

Answer: A

Explanation

If a VLAN map does not contain a match clause then it matches all type of traffic. Maybe this question is not clear but we should understand as “Which of the following actions are taken in a VLAN map that does not match a match clause?”.

Question 9

Refer to the exhibit. What will happen to the traffic within VLAN 14 with a source address of 172.16.10.5?

Switch# show ip access-lists net_10
Extended IP access list net_10
10 permit ip 10.0.0.0 0.255.255.255 any
Switch# conf t
Switch(config)# vlan access-map thor 10
Switch(config-access-map)# match ip address net_10
Switch(config-access-map)# action forward
Switch(config-access-map)# exit
Switch(config)# vlan filter thor vlan-list 12-16
A. The traffic will be forwarded to the router processor for further processing.
B. The traffic will be dropped.
C. The traffic will be forwarded to the TCAM for further processing.
D. The traffic will be forwarded to without further processing.

Answer 9

Answer: B

Explanation

The source address of 172.16.10.5 is not matched with access list net_10. Something like this at the end of the access-map:

vlan access-map thor
action drop
-> The traffic from 172.16.10.5 is dropped -> B is correct.

Question 10

How are VACLs configured?

Answer 10

as a VLAN access map

Question 11

How are VACLs applied

Answer 11

to a VLAN and not to a VLAN interface (SVI)

Question 12

What does *VACL* stand for?

Answer 12

VLAN Access List

Question 13

What is a *VACL*?

Answer 13

A VACL is applied to VLANs and configured similar to route-maps.

Question 14

What does the *VACL Forward* action do?

Answer 14

VACL Forward allows traffic to be forwarded.

Question 15

What does the *VACL Drop* action do?

Answer 15

VACL Drop drops traffic.

Question 16

What does the *VACL Redirect* action do?

Answer 16

VACL Redirect sets a new destination interface.

Question 17

What does the *VACL Capture* action do?

Answer 17

VACL Capture is an enhancement of forward and allows forwarded traffic to be captured similar to SPAN.

Question 18

What configuration commands sets up a *VACL Access Map*?

Answer 18

• Sw1(config)# vlan access-map [seq-num]
• Sw1(config-access-map)# match ip address {acl}
• Sw1(config-access-map)# action {action}

Question 20

What configuration commands sets up a *VACL Filter*?

Answer 20

Sw1(config)# vlan filter <map-name> vlan-list <vlan-ids></vlan-ids></map-name>

Question 21

What useful show commands verifies *VACL*?

Answer 21

Sw1# show vlan access-map

Sw1# show vlan filter