Application of IP over DCC

An Ethernet port is used to connect the U2000 and NEs. The NEs are connected to each other through fibers or Ethernet.

Application 1:Gateway NE Mode

If the U2000 and the GNE connect to the same Ethernet (the U2000 and the GNE need to be in the same subnet), and other NEs are accessed in the gateway NE mode, you need not to add any static routes.

As shown in Figure 1, the U2000 with the IP address of 10.9.0.100 uses the nearby NE1 as the GNE to access other NEs. You need not to add static routes on the U2000 or NEs.

Figure 1 Gateway NE mode

Application 2:Gateway NE Mode (by Default Gateway)

If the U2000 is connected to the GNE through a router and other NEs are accessed in the gateway NE mode, you need to add a default gateway on the U2000 and on the GNE.

As shown in Figure 2, the U2000 with the IP address of 10.100.11.12 connects with the GNE (NE1) through a router and accesses other NEs in the gateway NE mode. In this case, you need to set a default gateway on both the U2000 and NE1. Set the default gateway on the U2000 to 10.100.11.1, and that on NE1 to 10.9.0.254.

Figure 2 Gateway NE mode (by default gateway)

Application 3: Direct Connection Mode (by Static Routes)

If the U2000 and the GNE connect to the same Ethernet and other NEs are accessed in the direct connection mode, you need to set on the U2000 the default gateway to the IP address of the NE that is connected to the U2000 directly. Or you need to add the static route to the non-GNEs, with the forwarding address as the IP address of the GNE.

As shown in Figure 3, if the U2000 with the IP address of 10.9.0.100 needs to access NE3 directly, you need to add the static route to 192.168.0.0/24 on the U2000.

Figure 3 Direct connection mode (by static routes)

Application 4: Direct Connection Mode through a Router (by Static Routes)

The U2000 connects to the Ethernet port of a certain NE through a router and accesses other NEs in the direct connection mode. You need to perform the following operations.

On the U2000, set the static route to the GNE and non-GNEs.

On the GNE, set the default route to the U2000.

Add static routes to the U2000 on the destination station and the intermediate station.

As shown in Figure 4, the U2000 with the IP address of 10.100.11.12 connects to NE1 through a router and accesses NE3 in the direct connection mode. Suppose the IP address of the U2000 is 10.100.11.0 (subnet mask 255.255.255.0). Perform the listed operations:

Add the static route on the U2000 to the gateway 10.9.0.2.

Set the default gateway on NE1 to 10.9.0.254.

Add the static route on NE2 to 10.100.11.0, with the next hop address as 10.9.0.2.

Add the static route on NE3 to 10.100.11.0, with the next hop address as 192.168.0.2.

Figure 4 Direct connection mode through a router (by static routes)

Configuration Requirements

If NEs communicate with each other through IP over DCC, note the following rules for setting the network scale.

To prevent data loss, limit the number of NE nodes in the same OSPF area to 60.

When using the U2000 to monitor NEs, limit the number of non-GNEs monitored by one GNE to 60.

If NEs communicate with each other through IP over DCC, note the following rules for setting the IP address.

If NEs communicate through IP addresses on the network layer, each NE need to have a unique IP address to avoid routing error due to conflict.

NEs support standard A, B, C types of IP addresses, that is, the IP address ranges from 1.0.0.1 to 223.255.255.254. The 127.x.x.x, a loopback address, cannot be used.

The IP address must be used with the subnet mask. The subnet mask supports consecutive masks in addition to natural masks, for example, 255.255.224.0.

When the IP over DCC communication is used between a GNE and a non-GNE, the IP addresses can be of different network sections.

The GNE and non-GNEs cannot be in the same IP subnet. The NEs managed through the same GNE can be in different IP subnets.

Do not configure one GNE and one non-GNE into the same IP subnet.

The Ethernets in the network must belong to different subnets. Otherwise, a routing error will occur in the whole network. This is not allowed.

The subnet masks of the NEs must be the same.

The priority of static routes is higher than that of dynamic routes. If there is a conflict, static routes take priority.