Server Fault is a question and answer site for system and network administrators. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Does anyone know an ADSL router that allows to disable routing between switch ports? For example:
- part of network connected to port 1 on router can access the Internet but cannot see the part of network connected to port 2 on router
- the same for port 2

The whole network can access the Internet but cannot access each others segments. The subnet is the same for both ports. I don't want to use different subnets because then someone can change their address and get access to the other segment.

share|improve this question
up vote 1 down vote accepted

draytek vigor 2820 and upwards all do which is called Port based vlans.

share|improve this answer
That's exactly what I've been looking for. Thanks! – Alakdae Nov 25 '09 at 14:30

Is there a reason that the IP subnet must be the same on both ports?

What you attempting to do is normally done through the use of separate subnets/VLANs, with an ACL/firewall rule restricting access between the two subnets.

Briefly, without using vendor specific config:


Port 1 -> VLAN 10
Port 2 -> VLAN 20

From to DENY
From to DENY

Some of Cisco's SOHO router/firewall devices (e.g. ASA 5505 or 871 ISR) support VLANs and inter-VLAN ACLs. Other vendors such as Draytek may also provide what you need.

share|improve this answer
That's what I've been thinking to do, but on the cheaper routers it is not possible. And I need to minimize the cost. Thanks for the answer though. – Alakdae Nov 25 '09 at 14:29

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.