DHCP client unable to see external net

[Christopher Blough]

Greetings,       I have recently made my first foray into Debian. Being a linux newbie, the entire experience has been filled with a great deal of learning. That said, I've run into an odd issue that I haven't been able to resolve via HOWTO or through older mailing list posts.      I am using the current Debian release (Woody 3.0r2), using a bootable CD-ROM with the disk 1 .iso image. What happens is pretty simple to explain:       My network card (I'll use my 3c905B-TX as an example, since I've used several in the course of trying to get this to work) is successfully picking up an IP address and DNS information from my router (which serves as a firewall and DHCP server). Looking at resolv.conf shows me a list of valid DNS servers. I am able to ping the other three Windows-based boxes on my LAN (same subnet as this box). However, any attempt to resolve an internet address or to go outside of the router meets with a generic 'network is unreachable' error.   route add -net default gw 209.xxx.xxx.xxx also returned a 'network is unreachable' error. Essentially, I am seeing my LAN boxes fine, but am completely unable to go past my firewall. Before anyone asks, yes, it's properly punched. All external ports and connections are allowed.   I've tried installing with both the 2.2 kernel and 2.4.18 kernel accessed via F3 at boot: , and the results are the same -- the internal network is reachable, but anything past there, or any attempt to manually add routing information fails.   dhcp.leases shows lease information, and attempts to manually set the device (eth0) give the same results. ifconfig attempts return an active ethernet device that looks properly configured, with the proper IPs (though, the MTU is set to 1492).   Does anyone have any ideas, here? I've been banging my head against the wall on this one for 2 days.