private vlans vs. access lists

Unanswered Question
Feb 11th, 2007

It seems to me that private vlans are easier to set up and use less processor, and that's the advantage over using access-lists to prevent routing between vlans (when needed). Are there reasons to perhaps use access lists instead?


I have this problem too.
0 votes
  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 4 (2 ratings)
abdulkadernaina... Sun, 02/11/2007 - 20:47

Access list is used to block even a single host and in particular direction either inbound or outbound

albert.remo Sun, 02/11/2007 - 21:22


Good day! If hosts from these VLANs are not to connect with each other, you can use Private VLANs. But if in one way or another, interaction with hosts on these different VLANs would be required, you would definitely require some security. Access list is the most basic form of security incorporated in the IOS. Access list provides diffrent levels of security such as interface, port and even application. With access lists, you're actually separating them L3 to L7 as compared to private VLANs wherein you completely block them via L2.

Hope this helps,



Jon Marshall Sun, 02/11/2007 - 23:43

Hi Matt

Private vlans are used when you want to control traffic between hosts/servers that are on the same vlan. They allow you to segregate hosts or groups of hosts from each other while still using the same IP subnet addressing.

if you want to conrol traffic between vlans then asd you say you would use access-lists on your SVI's.




This Discussion