3com 500 Manuel D’Utilisation

 

 

A

 

P

 

P

 

E

 

N

 

D

 

I

 

X

 

 A: 

 

B

 

R

 

I

 

D

 

G

 

I

 

N

 

G

 

 

 

A

 

N

 

D

 

 R

 

O

 

U

 

T

 

I

 

N

 

G

 

Using of any of the address classes in a private TCP/IP network is not a 

 

problem, providing that connections outside of that private network 

 

to external public or private TCP/IP networks are never needed. If a 

 

private IP addressing number scheme is established within a private 

 

corporate network, connections out of that network to external public 

 

or other private TCP/IP networks, can be achieved via a computer 

 

which has software which enables it to act as an IP 

 

. These 

 

devices, if configured correctly, provide the IP numbering/address 

 

translation between the two networks. 

 

 

Subnet Masking is a mechanism which can be enabled in computer 

 

and communications equipment which tells the equipment and the 

 

network, which parts of the IP address are to be used as the 

 

 

 

identifier and which are the 

 

 identifier. 

 

A subnet mask consists of a similar field structure to that of the IP 

 

address (123.123.123.123). For example:

255.255.0.0

 

This means that the first two three digit bytes of the IP address (the 

 

fields 

 

 by - 255.255) are to be recognized and used as the 

 

Network address, and the last two bytes (those set to .0.0) are to be 

 

used to identify the Host address. 

 

An alternative way of expressing a subnet mask is a single number 

 

indicating how many bits of the IP address are to be used for the 

 

network address. For example 255.255.0.0 can be expressed as 16 while 

 

255.255.255.192 can be expressed as 24.

 

The AccessBuilder 500 can be configured to use subnet masking to 

 

enable ISDN Autocalls to be made on groups of IP addresses or on 

 

specific IP addresses. 

 

Normally, a subnet mask would be set so that any IP address, in a range 

 

of hosts on a destination LAN which are detected on the unit’s locally 

 

connected LAN port, causes an ISDN Autocall to be made out to that 

 

destination.