LassePoulsen's questions

I have encountered a very weird error on ubuntu-server (8.04), I have no idea why dhclient is not allowed to set the network settings! I'm not the one who installed the server in the first place, so i don't know much about the setup. The server is only used as a firewall/gateway (custom iptables script) it's got three nic's one for internet, one for LAN and one for DMZ. Now the ISP have changed settings from static ip to "static" ip assigned through dhcp, and i cant really use it.

Sadly I can't just set the IP statically since the ISP closes my connection when the dhcp lease ends :o

This is the error i get: (and then it just hangs there..)

root@fw:~# dhclient eth2
Internet Systems Consortium DHCP Client V3.0.6
Copyright 2004-2007 Internet Systems Consortium.
All rights reserved.
For info, please visit http://www.isc.org/sw/dhcp/

SIOCSIFADDR: Permission denied
SIOCSIFFLAGS: Permission denied
SIOCSIFFLAGS: Permission denied
Listening on LPF/eth2/00:50:52:c1:a1:32
Sending on   LPF/eth2/00:50:52:c1:a1:32
Sending on   Socket/fallback
DHCPDISCOVER on eth2 to 255.255.255.255 port 67 interval 8
DHCPOFFER of 2.10.56.19 from 93.87.36.42
DHCPREQUEST of 2.10.56.19 on eth2 to 255.255.255.255 port 67
DHCPACK of 2.10.56.19 from 93.87.36.42
SIOCSIFADDR: Permission denied
SIOCSIFFLAGS: Permission denied
SIOCSIFNETMASK: Permission denied
SIOCSIFBRDADDR: Permission denied
SIOCSIFFLAGS: Permission denied
SIOCADDRT: Operation not permitted

for now i've fixed it by running killall dhclient; dhclient eth2 every hour and then setting static IP settings for the interface, this is enough to keep the connection live! but it's a pretty ugly hack in my opinion..

I'm going to connecting two LAN's in some way, I imagine some form of VPN tunnel between the gateway/router on each side. Both routers have Ubuntu-server 10.04 installed, but the only vpn-like experience I have is setting on-demand TCP-port forwarding with ssh, but I want this to work for windows clients as well.

The two networks are only connected through an Internet connection, and I don't want my private traffic exposed (traffic like samba).

So how can I do this?

What measures can/should I take to make sure that security around my SSH server is absolutely impermeable?

This will be community wiki from the start, so lets see what people do to secure their servers.

How can I set up my WiFi to be used as wireless access point on Ubuntu Server?

I have a local Ubuntu Server, it has a wireless card in it (802.11a/b/g/n) and I really want to set it up as an 802.11n access point since my normal access point does not support N.

It needs to work as a switch as well so I can connect and get DHPC through.

Edit: I don't see Network Manager as a good solution since it depends on a lot of X11 packages, and i don't want that on a server.