The Neighbor Gateway Reachable Networks screen (#158) in
Figure 9-9 "Neighbor Gateways Reachable
Networks Screen" is displayed when you select a gateway name at the
Neighbor Gateways screen (Figure 9-8 "Neighbor
Gateways Screen") and press the [Add] or [Modify] function
key. It is also displayed when you type the path name:
@NETXPORT.NI.NIname.INTERNET.gatewayn
in the command window of any screen and press the [Enter] key, where
NIname is a configured FDDI NI, and gatewayn is the configured
FDDI neighbor gateway name.
Figure 9-9 Neighbor Gateways Reachable Networks Screen
After you have entered all the required data, press the [Save Data]
function key to transfer the data displayed on the screen
to the configuration file you are creating or updating. Verify that
the data record has been created by checking that the Data flag
is set to Y.
NOTE: The information configured in this screen can extend to more than
one page, if necessary, to allow configuration of up to 2550 reachable networks
per link (255 pages and 10 reachable nets per page). Press [Next Page]
to proceed to a new page. Press [Prev Page] to display a prior page. Use
[First Page] to display the first page (for example, if you are viewing
the third page, pressing [First Page] will immediately display the first
page). Press [Last Page] to display the last page of reachable networks
that has been configured. To consolidate reachable networks entries (from
several pages, for example) press [Condense Page].
Fields
Neighbor gateway IP internet address
Enter the full network address of a gateway node
(on this network) that is to be used to reach other networks (any
network in the same internetwork other than the network of which
this node is a member). The network portion of the address must
be the same as that entered on the IP Protocol Configuration screen
for the network interface you are configuring; however, the node
portion need not match.
There are two methods of entering an internet protocol (IP)
address within NMMGR:
Enter the fully qualified IP address (for example, Class C,
C 192.191.191 009)
OR
Enter only the network (nnn) and node (xxx)
portions of the IP address as four positive integers between 0 and
255 separated by periods or blanks (for example,
15.123.44.98).
You need not enter the following items as NMMGR will fill these in:
- Class A, B, C
- Leading zeros for the network and node portion of the IP
address.
Addresses are made up of a network
portion and a node portion. The
supported classes of network addresses have the following forms:
Class C:
C nnn.nnn.nnn xxx
Class B:
B nnn.nnn xxx.xxx
Class A:
A nnn xxx.xxx.xxx
where nnn is a value ranging from 000 to 255, representing eight
bits of the network portion of an address and xxx is a value
ranging from 000 to 255, representing the node portion of the address.
Note that network and node values of all zeros or all ones are not
allowed. These are special values.
The leftmost group of nnn has the following ranges for each
address class:
Class C:
192-223
Class B:
128-191
Class A:
001-126
The network address (network portion of the IP address) configured in
NETXPORT.NI.NIname.PROTOCOL.IP must match the neighbor gateway
IP internet address configured in the current screen.
Default value: None
Configured reachable networks IP network address
Enter the internet addresses of the remote networks that
can be reached through the gateway whose network address is configured
in the previous field.
You can also designate this gateway as a default gateway by entering an
"at" sign (@) in one of the Configured reachable networks IP
network address fields. The network will route messages to the
default gateway if it is unable to locate their destination by any other
means. The default gateway will then attempt to locate the destination.
When specifying reachable networks, entering only the network portions,
and optionally the subnet, of the IP address (setting the node portion to
all zeros) allows this node to communicate with any other node on the
remote network.
If the remote network is subnetted, you can restrict communication of
this node to particular subnets by entering the decimal equivalent of
those subnets and including the IP mask in the IP mask field.
To allow this node to communicate with other subnets on the local
network, enter the decimal equivalent of the subnet in the IP network
address field and enter the subnet mask in the IP mask field. If you do
not enter a subnet mask, one of the following occurs:
If the IP address is the same as the node you are configuring,
the IP mask configured in the IP Protocol Configuration screen
(Figure 9-5 "IP Protocol
Configuration Screen") is used.
If the IP address is different from the node you are
configuring, NMMGR assumes no subnets.
Related screen:
NETXPORT.NI.NIname.INTERNET
This path name corresponds to the Neighbor Gateways screen. A
Neighbor Gateway Reachable Networks screen must be configured
for each gateway configured in the Neighbor Gateways
screen.
IP mask
The IP mask identifies a portion of the IP address for subnets. The
subnet is specified in the same format as an IP address, that is, the
32-bit mask is grouped in octets expressed as decimal integers and
delimited by a "." or a space. For example, a mask for a class A address
with the subnet field being the first 8 bits of the
node portion would be expressed
as 255 255.000.000. The default is no IP mask.
Configured reachable networks hops
Enter the internet hop count to the reachable network whose
IP address is configured to the left of the hops field. (The internet
hop count is the number of full internet gateways that will be used to
route a message to the destination network. If two partner gateway halves
are used as part of the internet route, they are counted as one hop.)
Hop count is used internally to determine which neighbor gateway
(if more than one exists) is on the shortest path to the remote
network. If more than one gateway can reach a given remote network,
and the number of hops to the remote network is equal for each gateway,
you can specify which gateway the network transport will use by
configuring an artificially high hop count. The network transport
will always use the gateway with the lowest hop count. If the same
hop count value is configured for multiple gateways, the network
transport will choose internally from among the routes with equal
hop counts.
Range: 1-32767
NOTE: To delete a reachable network entry, fill the field
to be deleted with blanks and press the [Save Data] function key.