Louwrentius

A feature on more recent HP Procurve models (18xx series, such as 1810G etc.) is called "Auto DoS". You can find it in the section "Security" and then "Advanced security".

If you enable the Auto DoS feature, traffic is blocked based on one of these conditions:

• the source port (TCP / UDP) is identical to the destination port (NTP, SYSLOG, etc)

• the source port (TCP / UDP) is 'privileged' thus in the range of 1 -1023.

This will cause all kinds of problems, but first this: "Why on earth is a Layer 2 device filtering on Layer 3?". This is just insane.

NTP does not work any more. Syslog traffic will not arive. VPN traffic may not arrive.

This issue cost me a lot of time to solve. I first blamed our Firewall, but the actual traffic arrived on the tagged trunk port on the affected switch. The traffic somehow was not sent to the switch port on which the destination device was connected.

Affected products:

HP ProCurve 1810G - J9449A ( 8 ports ) and J9450A ( 24 ports )

If you want a router for distribution of internet to your computers at home, there are several options.

• buy some embedded device from Linksys, Draytek, Asus, 3com, ZyXtel or netgear

This type of hardware is cheap, economical, and gets you up and running in a few minutes. The downside is that you can't do much else with these things. Yes, there are many custom firmwares, which allow you more freedom, but the hardware is often the limiting factor.

• convert a regular PC into a router

If you want more than just routing, building your own router using a(n) (old) PC is the preferred course of action. The downside is that a PC often uses more 'juice' than an embedded device.

However, those new Atom-based PC's may be a very nice option. Just add a second network card, though an USB-port or a low profile PCI card and you have something far more flexible than an embedded router.

• convert a laptop into a router

It sounds a bit strange and silly at first to use a laptop as a router, but it makes sense when you think of it.

1. It is economical in terms of power usage
2. It has a build-in UPS called a 'battery'
3. It has a build-in screen and keyboard

All these things are an advantage regarding option 2.

Nowadays you can have a netbook for only 300 euros. It is more expensive than an embedded device, but almost as economical and provides much more performance and flexibility.

I've been running an old laptop as a router for 6 months without problems. Unfortunately, the disk died due to old age, but that can happen to any computer. I'm now running an old mac mini intel machine as a router.