Does a secured guest network on my router create significant vulnerability?

Question

Guests need to use Wi-Fi when they come by, so to minimize risk, I've simply kept a secondary secured router running for guests since it's not possible to understand anybody's computer & security habits with certainty.

The guest router is starting to go bad and the cost of new high performance routers are high. If I open a secondary secured guest network separate from my own, am I exposing myself to vulnerability? I keep the router firmware up to date, and it's not a model known for much vulnerabilities.

Answer 1

If the router has an explicite feature to create a guest network then it is likely separated from the normal network - but you still might be liable to what the guests do since they still share the internet access for you. If the router does not have an explicit guest network but instead something else you use as guest network than it is unknown how good the separation actually is.

Of course, this is only assuming that the guest feature is implemented in this specific router like it typically is (i.e. full separation from the other network) and there are no bugs. While this is probably the case one cannot be sure.

Answer 2

It depends on how the "Guest Network" is implemented. If it's on a VLAN (virtual local area network), the separation should be sufficient, given that it is configured correctly.