Internet stops working right after startup
First of all, apologies if this was sent to the wrong list.
I've recently started using debian lenny and I'm having some issues
sharing my internet connection. When booting my pc, a little before
GNOME comes up and all clients attached to the pc can access the
internet just fine. Only about 20 seconds later all internet
connectivity stops working on the whole LAN. DNS resolving doesn't work
anymore, and just pinging known ip addresses times out as well. However,
connections to and from the debian pc still work fine. When I restart my
network card using "ifdown eth0 ; ifup eth0" everything works fine again
and remains that way (eth0 is the network card connected to the internet).
I believe this is not a routing problem because the routing table
remains the same after bringing eth0 down and up again. I'm not entirely
Interestingly, I pretty much believe to have solved this problem by
removing the network-manager package at first, however I somehow took
down the entire desktop environment with it. Before then, the symptoms
were the same but the cure was to just restart ipmasq. Now, bringing the
whole interface down is required, restarting ipmasq seems not to be
sufficient. I reinstalled GNOME and sadly this problem returned with it.
Some details that might help identify my problem:
- I set ipmasq to start after services have been started using
- in /etc/network/interfaces, for eth0 I execute a script after eth0 is
brought up. This script initializes iptables rules and ip masquerading.
- I use dnsmasq as DHCP and DNS server.
- The eth0 interface gets it's IP from a DHCP server by my ISP, eth1 has
a static ip.
Any help debugging this would be greatly appreciated.