Mac OS X, once you get a bit used to it, might become your favorite OS! Of course, it has its oddities, but… we all do!

Now… one of Mac OS X’s oddities is the fact that the Samba protocol implementation isn’t so brilliant. I have an Ubuntu box on which I run a Samba server. I have a shared folder, and in it I have created a symbolic link. When connecting from Mac OS X to that folder, the symbolic link can’t be followed (it appears to be a shortcut file, and when clicked, pops an error with the option to fix the link, but with no success either). From Windows, it worked fine.

The solution to this symbolic link issue was to add in the “general” group of the Samba server configuration file the following line:

unix extensions = off

My Samba configuration file is “/etc/samba/smb.conf”. I then restarted the Samba server and reconnected from Mac OS X, and it worked! It also works from Windows too

So I installed a new network card on the system, and it became eth1. The first one, eth0, was connected to network 192.168.2.0. Now, I connected eth1 to network 192.168.1.0. Both networks provides DHCP.

The first issue was when I configured both NICs with DHCP. No outside access was available on the box because there were two default gateways. So I configured eth1 as static, and didn’t specify any default gateway for it. But this rendered the internet connection through eth1 useless, because all the traffic (for the outside world) was routed through eth0 now. So when the downloading service was bound to eth1, it couldn’t connect anywhere outside the network.

After some searching effort on the Internet, I found this solution:

- /etc/network/interfaces:

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
iface eth0 inet dhcp

# The secondary network interface
auto eth1
iface eth1 inet static
address 192.168.1.2
netmask 255.255.255.0

up /etc/network/prioritize_networks.sh

- /etc/network/prioritize_networks.sh:

#!/bin/sh

#Set up the first subnet's routing table (we'll name it 70)
ip route flush table 70
ip route add table 70 to 192.168.2.0/24 dev eth0
ip route add table 70 to default via 192.168.2.1 dev eth0

#Set up the second subnet's routing table (we'll call it 80)
ip route flush table 80
ip route add table 80 to 192.168.1.0/24 dev eth1
ip route add table 80 to default via 192.168.1.1 dev eth1

#Create the rules to choose what table to use. Choose based on source IP
#We need to give the rules different priorities; for convenience name priority
#after the table
ip rule add from 192.168.2.0/24 table 70 priority 70
ip rule add from 192.168.1.0/24 table 80 priority 80

#Flush the cache to make effective
ip route flush cache

So now all the traffic goes by default through eth0, but all applications bound to eth1 are routed through the correct gateway of 192.168.1.0 network.

I found this hack here: http://www.physics.umd.edu/pnce/pcs-docs/Glue/linux-route-hack.html

Hope this help anybody.

1. I am using bash - this brings most of the features I enjoy: auto-complete at TAB and previous commands list being the most important. To enable bash you have to edit the file “/etc/passwd” like this (note the path to the console at the end):

username:x:100:100:NameOfUser:/homepath:/bin/bash

2. I am making vim work – vim is my preferred editor on Unix. For that, I must install vim (using Blastwave) and put the path in the PATH variable. See number 3 for this. After making vim work, I am setting it to work as I like – like on a Linux console . To do that, I am creating a file named .vimrc in my home folder with the following content:

set nocompatible " must be the first line
:syntax enable
filetype on
filetype indent on
filetype plugin on
set laststatus=2
set statusline=%<%f\%h%m%r%=%-20.(line=%l\ \ col=%c%V\ \ totlin=%L%)\ \ \%h%m%r%=%-40(bytval=0x%B,%n%Y%)\%P
set backspace=2

3. I am configuring the console to set vim as the default editor, to set the PATH with everything I need, to set the pager with more and to configure the shell prompt. For this, I am creating a file name .profile (or edit if existing) with the following content:

export PATH=/usr/bin:/opt/csw/bin
export TERM=linux
export PAGER=more
export EDITOR=vim
export PS1='[\u@\h \w]\$ '

So… this is it! Now I have a much nicer console!

Today I set up a new way to connect to my servers from anywhere. I installed a proxy on the office server, and configured PuTTY to use it for the connections to the secured servers. The following are the steps to configure a Linux server (Ubuntu in my case) and PuTTY to make a SSH connection through a proxy:

1. Install mod_proxy and mod_proxy_connect for Apache, and enable them. In Ubuntu (mine is 8.04), these modules are already installed and all you need to do is to enable them:

# a2enmod proxy
# a2enmod proxy_connect

2. Configure the proxy by editing the “proxy.conf” file:

<IfModule mod_proxy.c>

    ProxyRequests On
    AllowCONNECT 22

    <Proxy *>
        AddDefaultCharset off
        Order deny,allow
        Allow from all
        AuthType Basic
        AuthName "SSH Proxy"
        AuthUserFile /path/to/password/file
        Require user myusername
    </Proxy>
    ProxyVia Block
</IfModule>

3. Restart Apache
4. Configure PuTTY to use the proxy for the corresponding connections. For this, in the left tree, the “Proxy” submenu in the “Connection” menu must be used. There, select “HTTP” as Proxy type, then enter the hostname of your newly configured proxy, the username and password.

Now you should have a functioning proxied SSH connection! Cool!