Execute cron script over specified network interface

[stewart_butler]

At school, I have two networks: ethernet, and wireless. The wireless network requires authentication; after a period of inactivity, it logs you out of the authenticated MAC address pool, and you have to log back in. This is extremely annoying if you are switching between hardline and wireless as much as I do on my laptop.

I created a login script using Python, and run it on cron. However, at home the connection to the wireless network is maintained so that as soon as the hardline is unplugged the computer switches immediately to the wireless network. Due to the inactivity protocol, though, this isn't viable at school. Also, if you are not connected VIA the wireless network, the login script does not work (since your IP is out of the wireless range.)

Is there some way to send a ping packet, or run a cron script, through the wireless network, even when all other connections are running through the ethernet connection? Or otherwise specifying a network interface for a connection? I haven't been able to locate any information on it, but it would be helpful if anyone has a hint.

Stewart
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Sager NP2090 (Compal IFL90), Core 2 Duo T770 2.4GHz, 320gb SATA 5200rpm, 2GB RAM, Gentoo

AMD 64 X2 4400+, 3GB ram, 1x80gb IDE, 8x320GB SATA, Fedora 8

AMD Athlon XP, 1GB ram, IPCOP

et al.

[desultory]

Consider your routing tables. If the wired and wireless networks have any divergence in the routing tables it would not be difficult to ping something in that unique range.

[stewart_butler]

So you're saying set up a range of addresses in my firewalls that separates the wired and wireless networks, then ping something through that?
_________________
Sager NP2090 (Compal IFL90), Core 2 Duo T770 2.4GHz, 320gb SATA 5200rpm, 2GB RAM, Gentoo

AMD 64 X2 4400+, 3GB ram, 1x80gb IDE, 8x320GB SATA, Fedora 8

AMD Athlon XP, 1GB ram, IPCOP

et al.

[desultory]

The objective is to get the laptop to route traffic to an interface, actually having anything respond may well be optional. Unless the activity timeout only tracks successful connections, use a block of addresses which you know to be vacant.