Ip Addresses For Incoming Connections - Lantronix SCS Reference Manual

IP
In most network examples, the host portion of the address is set to zero.
Class
A
B
C
D, E
Consider the IP address 36.1.3.4. This address is a class A address, therefore, the network portion of the
address is 36.0.0.0 and the host portion is 1.3.4.
The subnet portion of the IP address represents which subnetwork the address is from. Subnetworks are
formed when an IP network is broken down into smaller networks using a subnet mask.
Subnetworks and subnet masks are discussed on page 6-5.
Note:
A router is required between all networks and subnetworks. Generally, hosts can send packets directly only
to hosts on their own subnetwork. All packets destined for other subnets are sent to a router on the local
network. The host portion of the IP address is a unique number assigned to identify the host.
For instructions on setting the IP address for your SCS, see your Installation Guide.

6.1.1 IP Addresses for Incoming Connections

When the SCS receives an incoming connection request (remote node or LAN to LAN), an IP address is
negotiated for the caller. The address agreed upon depends on the caller's requirements; some don't have a
specific address requirement, while others must use the same IP address each time they log into the SCS.
PPP negotiation is covered in Chapter 7, PPP.
Note:
If an incoming caller does not require the same address for each login, a dynamic address can be assigned
from an address pool. See Defining an IP Address Pool on page 6-3 for configuration instructions.
Some remote nodes or remote routers cannot be dynamically assigned an IP address. For example, a remote
node may offer a service to other hosts on its network. If the other hosts are statically configured to use that
IP address to contact the remote node, the node's IP address must not change. In this situation, two courses
of action may be taken: the caller may be permitted to choose any address, or may be restricted to a specific
address or range of addresses.
Permitting the caller to choose an address presents a number of risks. If the caller chooses an unacceptable
IP address (for example, the address of a server), it could affect the accuracy of routing tables elsewhere on
the network. In addition, the caller could choose an IP address intended for another host, compromising
network security.
Table 6-2: Available IP Addresses
Reserved
0.0.0.0
127.0.0.0
128.0.0.0
191.255.0.0
192.0.0.0
223.255.255.0
224.0.0.0 to 255.255.255.254
255.255.255.255
6-2
Available
1.0.0.0 to 126.0.0.0
128.1.0.0 to 191.254.0.0
192.0.1.0 to 223.255.254.0
None
IP Addresses