Network

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intro

This page was created for the sole purpose of creating clarity in the networking thingies at 0x20.

The schema

note: This schema accepts patches. You can find the .dia-file (sudo apt-get install dia) at http://members.0x20.be/cedric/Network_0x20.dia VPN 0x20.png

Sites

Whitespace

Whitespace, our hackerspace, has a LAN which connects local machines in the network 172.22.32.0/24. We provide ethernet and Wifi access to connect to the network.

IBBT

Our friends from IBBT (http://www.ibbt.be) have provided us with a virtual server in their data center, which is awesome! It has a massive internet connection and that is why this server is often referred to as "Big Pipe"<ref>Big pipe server</ref>.

VPN

To link 2 locations you have 2 options:

  1. Provide your own infrastructure: connect the two sites with a physical cable
  2. Use existing infrastructure to connect the two sites: connect through the interwebs

For a whole bunch of reasons, option #1 is a bit impractical, so the way to go is through the interwebs. That is exactly what is done between 0x20 and IBBT, we've created a so called Virtual Private Network or VPN, which in this case is nothing more than a point-to-point tunnel over the internet connecting 0x20 and IBBT in the same private network. This setup is documented in project OpenVPN<ref>Project OpenVPN</ref>.

Connection to internet

ISP: Dommel

After discussing multiple options, we decided to go with Dommel: fast access, cheap, no caps, no ports blocked. We went with the lower cost - lower speed option, with the idea that, if we want more, we can always upgrade.

Note: We are currently not using anything of the web- and mailservice below.

Connection details:

adsl-number 100987582393
news-server: news.dommel.be
news-login: xxx@schedom.be
news-pass: xxx
pop3-server: pop.dommel.be
smtp-server: relay.dommel.be
webmail: webmail.dommel.be
wan-ip: 83.101.72.80

Advanced modem/router settings:

protocol: rfc 2684 (aka 1483) multi-protocol over atm (bridged or routed)
vpi/vci: 8/35
ipaddress: automatic/dhcp
encapsulation: llc
password: not needed
nameserver1: 193.109.184.72
nameserver2: 193.109.184.75

web- and mailservice:

Your personal homepage at http://yourchoice.dommel.be has not yet been activated. To activate, login at https://crm.schedom-europe.net with username "info@0x20.be" and password "xxx". Click on "My Packages" -> Click on the "E" at the right of your adsl-account. You can configure your @dommel.be emailaccounts by clicking on the "O".


If you have any questions, please first check our support pages at https://crm.schedom-europe.net (click on "online faq"). If you cannot find an answer to your questions here, you can open a ticket at https://crm.schedom-europe.net (click on "support-desk"), or contact us by telephone every workingday between 09.00 and 18.00 (+32 70 224 305) or by fax (+32 70 224 305).

Wireless Antwerp

We also have a connection to the wireless antwerp network Wireless_Antwerp

LAN @ 0x20

I'm currently in the process of creating a new intranet at 0x20 with server Kimball as the central server for DHCP, DNS and Routing.

Network interfaces on Kimball

Kimball has two network interfaces:

# The primary network interface
# eth0 is the WAN-side of our router and takes an IP from the old 0x20 network over DHCP
auto eth0
iface eth0 inet dhcp

# eth1 is the LAN-side of our router. It has a static ip and currently it uses Soekris as DNS server
auto eth1
iface eth1 inet static
address 172.22.42.1
gateway 172.22.42.1
netmask 255.255.255.0
network 172.22.42.0
broadcast 172.22.42.255
nameserver 172.22.32.14

Routing Configuration on Kimball

Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
default         soekris.0x20.be 0.0.0.0         UG    0      0        0 eth0
172.22.32.0     *               255.255.255.0   U     0      0        0 eth0
172.22.42.0     *               255.255.255.0   U     0      0        0 eth1

DHCP Service on Kimball

Kimball is configured to provide Dynamic Host Configuration to hosts on the eth1 (LAN) side of the network. The configuration can be found in /etc/dhcp/dhcpd.conf:

# The ddns-updates-style parameter controls whether or not the server will
# attempt to do a DNS update when a lease is confirmed. We default to the
# behavior of the version 2 packages ('none', since DHCP v2 didn't
# have support for DDNS.)
ddns-update-style none;

# option definitions common to all supported networks...
option domain-name "0x20.be";
option domain-name-servers 172.22.32.14;

default-lease-time 6000;
max-lease-time 7200;

# If this DHCP server is the official DHCP server for the local
# network, the authoritative directive should be uncommented.
#authoritative;

# Use this to send dhcp log messages to a different log file (you also
# have to hack syslog.conf to complete the redirection).
log-facility local7;

subnet 172.22.42.0 netmask 255.255.255.0 {
        option routers 172.22.42.1;
        option subnet-mask 255.255.255.0;
        option ip-forwarding off;
        range dynamic-bootp 172.22.42.100 172.22.42.200;
        default-lease-time 21600;
        max-lease-time 43200;
}

As you can see, Kimball hosts the 172.22.42.0/24 network and also acts as it's default gateway on 172.22.42.1 which is it's own static address on eth1. At the moment we provide the range 172.22.42.100-172.22.42.200 for DHCP.

I also had to tell dhcpd to listen for DHCP-requests on eth1 instead of on eth0. For this I updated the file /etc/default/isc-dhcp-server:

# Defaults for dhcp initscript
# sourced by /etc/init.d/dhcp
# installed at /etc/default/isc-dhcp-server by the maintainer scripts

#
# This is a POSIX shell fragment
#

# On what interfaces should the DHCP server (dhcpd) serve DHCP requests?
#       Separate multiple interfaces with spaces, e.g. "eth0 eth1".
INTERFACES="eth1"


References

<references/>