Revision 10 as of 2008-08-19 22:28:48

Clear message

Understanding UCC's network can be a bit challenging at first, but after a bit of reading you'll find that it is actually very challenging, and give up. This article is a general overview of how it works. TableOfContents

Layer One

There is a long piece of CAT5 running through the walls from the machine room to the Guild machine room in Cameron Hall (across from UWAnime). This plugs in to a 100M D-Link media converter, which leads to a similar media converter in the Guild comms room in the main Guild building. Our uplink is into an ITS managed switch called 'cruzob'. If your're looking for where the cable runs, it's possibly disguised as a network outlet cable in one of the other student clubrooms.

Machine Room

The machine rooms contains three core switches and a router:

  • Olive, a 24-port Cisco Catalyst 2900 series switch.
  • Lorenzo, a 48-port Cisco Catalyst 2950 series with some dead ports and dual gigabit uplinks.
  • Curviceps, a 24-port HP Procurve with full gig ports.
  • Madako, a linux-based router running iptables.

These are all labeled and in the rack. There is also a patch panel for the clubroom wall-ports at the top of the rack.

Clubroom

There is CAT5 cabling run from a patch panel at the top of the rack to a number of wall ports throughout the room. Where not enough wall-ports are available, there are small 5-port unmanaged switches used to attach more devices to the network.

Layer Two

Internal VLANs

UCC uses seven VLANs internally for various purposes:

  • VLAN 1: Network and server management.
  • VLAN 2: Machine room network.
  • VLAN 3: Clubroom network.
  • VLAN 5: Loft network (used for LANs).
  • VLAN 6: Wireless network.
  • VLAN 7: Printers.
  • VLAN 8: Netboot (Ubuntu port)

External VLANs

ITS trunks to us the following VLANs:

  • VLAN 11: SNAP.
  • VLAN 13: Our main uplink, provides us our internet connection and address space.
  • VLAN 102: Guild clubs. Not used by UCC, forwarded on to UniSFA.

Layer Three

Layer three at UCC is pretty nasty, and the firewall script alone probable deserves its own article. However, a brief summary of how it all works:

Subnets

There are a number of IP ranges used at UCC for various things:

  • 130.95.13.0/24 is the public address space for our AARNet connection. Incoming, non-peering traffic to these addresses is charged at 4c/mb. This range is routed to us via VLAN 13.
    • 130.95.13.0/26 is the machine room address range, internally routed on VLAN 2.
    • 130.95.13.64/26 is the clubroom address range, internally routed on VLAN 3.
  • 203.24.97.249/29 is the public address space for our Silk connection. Traffic to and from these addresses is unmetered. This range is also routed to us via VLAN 13.
  • 10.13.13.0/24 is a private range used for network printers. These addresses reside on VLAN 7 and are not routed outside.
  • 10.203.13.0/24 is our address range on the Resnet (college) network. Routed via VLAN 13.
  • 172.26.42.0/24 is for 'untrusted client machines' - there is some history here, but they are never routed outside the Uni (unless NAT is involved, which it is).
    • 172.26.42.8/29 is the Ubuntu Port (netboot install) network.
    • 172.26.42.96/27 is the range we use for PPTP.
    • 172.26.42.128/26 is the loft network range.
    • 172.26.42.192/27 is the 'ugg' wireless network range
    • 172.26.24.224/27 is used by Flying for the 'ucc' wireless network, currently unavailable.
  • 10.11.0.0/24 on the SNAP vlan (10.11.0.0/16 in total) is not leased out by the central SNAP dhcp server, so some IPs in this range can be taken for services. Currently 10.11.0.13 is the UCC SNAP SSH forward (which ends up at martello) and .11 is used by evil.

Routing and Firewall

Madako, the Linux router, is a beast of burden. See ["Network/Firewall"] for further information on the way it operates.

Higher Layers

Lots of port 80 traffic somehow gets slurped up by a cacheboy http proxy maintained by [AHC].

There is sometimes a PPTP server running on madako, though SSH tends to be the most reliable protocol for tunneling about UWA.

Configuration

Information on configuring the core switches can be found at ["Network/SwitchConfiguration"]. Information on configuring routing and firewalling can be found at ["Network/Firewall"].

Monitoring

There are various monitoring packages installed, links to which can be found on MissionControl.