We have been using the Zyxel PH660 for quite some time now and are pretty pleased with its reliability, performance and ease of configuration.
We had a customer who wanted to use the router in a unusual manor, in between the FTTC modem and his firewall (which is PPOE capable). The customer is always right so putting the router into route mode should be a simple matter of changing a check box on the web interface. Or so we thought.
After testing this configuration on our test bed I came up with some interesting issues, in that I could get to google and a couple of other sites but the majority would not come up. Cant be a routing issue I thought as traceroutes would work as did ping etc.
In the end I thought … must be MTU as that’s the only thing that we can influence our end which would cause such a strange issue.
Well in the end it was MTU, having tried various MTU settings we came up with 1492 which is generally the recommended setting but perhaps strangely not the default.