8.3 Looking ahead
The last eight sessions have been based on home networks, or the networks you would find in a small business. In large organisations or enterprises, however, the equipment used is more sophisticated, and networks are more complex because of the use of subnetworks. The next eight sessions focus on ‘enterprise’ networks and processes. For example, setting up a router in an enterprise network is very different from setting up a gateway in a home network. The following video looks briefly at some of the significant differences between home and enterprise networking.
Activity 3 Test yourself
1. In the video, an enterprise router is described as having two or more interfaces. This refers to the number of network interfaces. Why might such a router have more than two network interfaces?
To transfer data between more than two networks. A router’s function is to act as a gateway between networks, so that data packets can be transferred between networks. A router with four network interfaces can receive a data packet on one interface and forward it to one of the three networks connected to its three other interfaces.
2. The activity shows the interface of an enterprise router being set up manually via the command-line interface. Enterprise networks use DHCP, so why is manual configuring of some interfaces necessary?
On the public internet, network addresses need to remain constant so that packets can be directed to the right destination network. This means that router interfaces need to remain fixed.
3. Towards the end of the video, it is pointed out that some enterprises have an international spread, and yet ideally users’ experience should not be noticeably different when communicating with remote colleagues compared with local colleagues. What particular difficulties could be expected with such long-range communication (compared with local communication)?
One problem is increased latency for long-range traffic, which almost certainly has to pass through more routers than local traffic. Another potential problem is security, as data could be expected to be vulnerable on the public internet. (In fact, so-called ‘tunnels’ are used in practice to mitigate both problems. Data tunnels are virtual private lines, which nevertheless operate over the public internet, and data traffic can traverse them with less latency than ordinary IP traffic. Traffic in data tunnels is also usually encrypted.)