Distech Controls ECLYPSE ECY-STAT - About Routers, Switches, and Hubs; Connecting a Router

16 ECLYPSE Connected Thermostat (ECY-STAT)
Set the DNS IP address of the Domain Name System (DNS) servers in routers and in IP controllers
that have manually-configured IP parameters. Between one and three DNS IP address is usually pro-
vided by the Internet Service Provider (ISP). The second and third DNS addresses are for failover
should the first DNS become unavailable.
If you do not know the address of your DNS server(s), try the following publicly-available DNS server
addresses: primary = 8.8.8.8 and secondary = 4.4.4.4
Some ECY-STAT services use DNS to resolve Web addresses thereby allowing the service to oper-
ate.
About Routers, Switches, and Hubs
The differences between a hub, switch, and router are discussed in the table below.
Device Type Description
Hub
Every incoming data packet is repeated on every other port on the device. Due to this, all traffic is
made available on all ports which increase data packet collisions that affect the entire network, thus
limiting its data carrying capacity.
Switch
A switch creates a one-to-one virtual circuit that directs IP packets directly to the port that the
destination computer is connected to.
Router
Like a switch, a router learns the IP addresses of all devices connected to any of its RJ-45 ports to
create a routing table. If a data packet arrives at the router’s port with a destination IP address that is:
- Found in the router’s routing table, the router forwards the data packet to the appropriate port for the
device that has this IP address.
- For a network with a different network ID than the current network ID, the router forwards the data
packet to the uplink port where the next router will again either recognize the network ID and route the
data packet locally or again forwards the data packet to the uplink port. By being exposed to traffic, a
router adds to its routing table the pathways necessary to resolve a data packet's pathway to its final
destination, by passing through one or more routers if necessary.
Connecting a Router
The way a router is connected to other devices changes its function.
1
UPLINK
2 3 4
1
UPLINK
2 3 4
ROUTER
A
ROUTER
B
Connection to use ROUTER A as a router
To
Device
To
Device
To
Device
To
Device
To
Device
To
Device
To
Device
To
WAN
1
UPLINK
2 3 4
1
UPLINK
2 3 4
ROUTER
A
ROUTER
B
Connection to NOT use ROUTER A as a router
To
Device
To
Device
To
Device
To
Device
To
Device
To
Device
To
WAN
UPLINK
Function is
Not Used
Figure2: The Way a Router is Connected Changes its Function
On some routers, the uplink port is marked as WAN (Wide Area Network) and the numbered ports are
to be connected to the LAN (Local Area Network) devices.
IPv4 Communication Fundamentals