Exclude a vlan from IP ROUTING layer 3 switch

Answered Question
Jan 12th, 2010
User Badges:

I have set up a Layer 3 switch to do IP routing between the VLANS, There are a couple of VLANS that I do not want communicating with the other VLANS,

What is the best way to accomplish this, ACLS?

Correct Answer by Jon Marshall about 7 years 4 months ago

JasonWhitehead wrote:


The vlans I want to exclude only need to talk to the devices on the same VLAN and use the internet out of the default route


Jason


Well then yes, ACLs are the way to go eg.


vlan 10 is one of your isolated vlans = 192.168.10.0/24

vlan 5, 6, 7 are vlans you don't want vlan 10 communicating with


access-list 101 deny ip 192.168.10.0 0.0.0.255

access-list 101 deny ip 192.168.10.0 0.0.0.255

access-list 101 deny ip 192.168.10.0 0.0.0.255

access-list 101 permit ip 192.168.10.0 0.0.0.255 any  <-- this line for internet access


int vlan 10

ip access-group 101 in


Jon

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 5 (1 ratings)
Loading.
Jon Marshall Tue, 01/12/2010 - 12:46
User Badges:
  • Super Blue, 32500 points or more
  • Hall of Fame,

    Founding Member

  • Cisco Designated VIP,

    2017 LAN, WAN

JasonWhitehead wrote:


I have set up a Layer 3 switch to do IP routing between the VLANS, There are a couple of VLANS that I do not want communicating with the other VLANS,

What is the best way to accomplish this, ACLS?


Jason


Yes you can use ACLs on the L3 interfaces. Do these vlans you want to isolate need to talk to anything other than devices on their own vlans ?


Jon

Jason Whitehead Tue, 01/12/2010 - 12:48
User Badges:

The vlans I want to exclude only need to talk to the devices on the same VLAN and use the internet out of the default route

Correct Answer
Jon Marshall Tue, 01/12/2010 - 12:54
User Badges:
  • Super Blue, 32500 points or more
  • Hall of Fame,

    Founding Member

  • Cisco Designated VIP,

    2017 LAN, WAN

JasonWhitehead wrote:


The vlans I want to exclude only need to talk to the devices on the same VLAN and use the internet out of the default route


Jason


Well then yes, ACLs are the way to go eg.


vlan 10 is one of your isolated vlans = 192.168.10.0/24

vlan 5, 6, 7 are vlans you don't want vlan 10 communicating with


access-list 101 deny ip 192.168.10.0 0.0.0.255

access-list 101 deny ip 192.168.10.0 0.0.0.255

access-list 101 deny ip 192.168.10.0 0.0.0.255

access-list 101 permit ip 192.168.10.0 0.0.0.255 any  <-- this line for internet access


int vlan 10

ip access-group 101 in


Jon

Jason Whitehead Tue, 01/12/2010 - 12:56
User Badges:

Thank you so much, It is ridiculous how fast the respond time is on these forums, nothing but help here

Actions

This Discussion