Alcatel AST570, User Manual

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VLSM, CIDR
Supernetting and
Aggregation
14 Networking Services - IP
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3EC 17766 AAAA TCZZA Ed. 04
Next to traditional classful IP addressing, (sub)netmasking and
routing the AST570 features also the following new IP standards:
Variable Length Subnet Masking ( VLSM )
VLSM refers to the fact that one network can be configured
with different contiguous masks. This offers the capability to
allocate subnetworks with variable numbers of hosts, thus
allowing a better utilization of address space.
Classless Inter Domain Routing ( CIDR )
In CIDR, an IP network is represented by a prefix, which is the
IP address of a network, followed by a slash and, lastly, an
indication of the number of leftmost contiguous bits
corresponding to the network mask to be associated with that
network address.
Supernetting
A network is referred to as Supernet when a prefix netmask
boundary contains fewer bits than a network's natural -
classful mask.
Route Aggregation
Route Aggregation refers to the way CIDR and its prefix
notation can be used to advertise multiple IP networks with
one aggregate Supernet route indication.
Therefor, the AST570 is compliant to all relevant sections in
RFC1338, RFC1518 and RFC1519
See these RFCs for more information.