HP 3000 Manuals HP 3000 Manuals
Network Interface and Link Types
The network interface (NI), the software that provides an interface
between a node and a network, specifies the type and maximum number of
links that can be configured for a node. Because a node's network
interface determines what links can be configured for the node, links are
said to be configured underneath network interfaces.
There are seven types of network interfaces (in addition to loopback):
* LAN for IEEE 802.3 and Ethernet networks.
* FDDI for fiber optic networks.
* Token ring for IEEE 802.5 networks.
* Point-to-point for networks that use point-to-point routing.
* X.25 for X.25 networks.
* NS over SNA is no longer offered as a product and has been removed
from the Corporate Price List. The product is obsolete with no
plans for support.
* Gateway half for nodes that function as gateway halves.
Each HP 3000 connected to the network must have at least one LAN, token
ring, FDDI, point-to-point, or X.25 network interface configured. This
network interface must be associated with the network to which the system
belongs.
Number of Network Interfaces
A system can have up to 12 network interfaces (NI) configured. One of
these network interfaces must be loopback. For each network interface,
the maximum number of links you can configure and the kinds of links
possible are determined by the network interface type, as follows:
* A LAN network interface can have only one link configured under
it; however, a single link can reach a large number of nodes.
ThickLAN cable supports up to 100 nodes per segment; ThinLAN cable
can be used for up to 30 nodes per segment; and each Ethertwist
3000/iX can be used for up to 50 nodes. Up to two LAN NIs can be
active at a time per system.
* A token ring interface can have only one link configured under it;
however, a single link can reach a large number of nodes. Token
Ring 3000/iX Network Link can support up to 250 nodes per ring
using shielded twisted pair (STP) cabling at 4 or 16 Mbps and 50
nodes per ring using unshielded twisted pair (UTP) cabling at 4
Mbps.Only one token ring NI can be active at a time per system.
* An FDDI interface can have only one link configured under it;
however, a single link can reach a large number of nodes. FDDI/iX
Network Link can support up to 1000 9X7, 9X8 or Corporate Business
Systems. Only one FDDI NI can be active at a time per system.
* A point-to-point network interface can have up to 40 links
configured under it.Point-to-point links may be dial links, in
which a modem attached to a node is used to transmit and receive
data carried across telephone wires, or leased lines, in which
data is sent over data-grade lines leased from a private carrier.
Up to 11 point-to-point NI's can be active at a time (one NI must
be loopback) for a total of 12 NI's per system.
* An X.25 network interface can have from one to 11 links
configured, depending on the number of configured X.25 network
interfaces on the node. (A single node can have up to 11 NIs and
up to 11 X.25 links.) Each link can be connected to as many as
1,024 remote nodes, with communication allowed with as many as 256
nodes at the same time. Up to 11 X.25 NI's can be active at a
time (one NI must be loopback) for a total of 12 NI's per system.
* A gateway half network interface can have only one link configured
under it (the gateway half link). Links connecting two gateway
halves can be only NS Point-to-Point 3000/iX Network links. Only
one gateway half NI can be active at a time per system.
If more than one (non-loopback) network interface is configured on a
node, the network portions of the IP addresses configured for the
interfaces should differ to correspond to the multiple networks to which
the node belongs.
Refer to "Software Configuration Maximums" table 2-2 at the end of this
chapter for information on configuration path maximums.
Priority of Network Interfaces
If it is possible to reach a destination through more than one active NI,
the network determines which NI to select according to the following
priority:
loopback
FDDI
LAN
token ring
X.25
gateway half
point-to-point (router)
If more than one NI of a given type is active, (for example, two X.25
NIs) the network will select the one that it finds first.