Our router is configured with one public address and two internal networks, one for the company, one for guests. Both have different IP ranges (172.17.17.x and 172.17.18.x). Internet access from the first network works perfectly (via ether3). However, it doesn’t work well from the guest network (via ether5). And the behaviour is strange:
- If I try to ping from the guest network to the world I get timeouts
- Then I go to IP->Settings and disable and re-enable IP forwarding and the suddenly pings work
- If I ping another public IP it doesn’t work again.
- Re-enabling IP forwarding makes it work again
- Opening web pages takes forever only after about 1 minute they finally show up
The same behaviour is seen on the guest WLAN (which has the same IP address range) but not on the other internal network. I disabled almost all firewall rules, and it didn’t resolve the issue.
The strange thing is, this setup used to work until a few weeks ago. I did some update in between but we didn’t notice the problem until a guest came this week and couldn’t connect to the internet. I’m really running out of ideas.