[DominikHoffmann]

I have a host which connects through PPPoE on a DSL line. I want to reach it through ssh. However, it seems that, because the ISP requires PPPoE, the connection drops when idle. In a related post it is suggested to instruct the Network preference pane to keep the connection alive through a respective checkbox. In my case a router handles the PPPoE interface. I'll have to check, whether it has a similar option.

Regardless, do ISPs disconnect their PPPoE clients when idle on their own? Or, is it always the client which graciously disconnects? In the former case, it might be a little harder to make the network available to the outside.

Do you have any opinions or experience to share?

Dominik Hoffmann

[SWFan]

Thats a good question on which end is dropping the connection. I can tell you, I've always setup my equipment to keep the connection alive.

Right now, my Smoothwall box says I've been connected for a little over 11 days. I think the longest its ever sustained a connection was a little over 120 days. I'm using PPPoE via SBC DSL.

I have a feeling its the ISP that causes the disconnect, but as long as your client/router/firewall box is sending a signal periodically, it won't drop you.

[ghporter]

In general it's the ISP that drops the client. My SBC DSL connection is managed by a cable/DSL router that maintains the connection with a "keep alive" setting. This basically just has the router send packets when there's no client activity. Since this isn't metered service, there really isn't a business reason to expire a PPPoE connection, but it does help a bit with security. Such connections don't have a fixed Internet IP address, which can enhance security a bit, and the ISP can rotate the IP pool it uses for whatever management reason they might have (equipment maintenance, etc.).

I generally recommend using a router on a DSL connection for a number of reasons; this is a big one.

[DominikHoffmann]

Originally posted by ghporter:
...but it does help a bit with security.

True enough! If I can't connect to my Dad's router, because the connection is active only within so many seconds of when the last traffice originated from his LAN, his exposure to hackers is dramatically reduced, as well.

Such connections don't have a fixed Internet IP address...

... although the Zyxel Prestige 334 has dynamic DNS capability. Thus, I won't have to worry about the moving target aspect.

Now I just have get it to keep the connection alive...


Dominik Hoffmann

[DominikHoffmann]

The Zyxel Prestige 334 uses interesting terminology: "Nailed-up Connection." Since checking it I have been able ping the Zyxel, even though my dad shut down his computer, thereby discontinuing the net queries that would keep the connection alive before.