Cisco ONS 15454 Installation and Operations Guide, Release 3.2
Chapter 4, IP Networking

Table Of Contents

IP Networking

4.1 IP Networking Overview

4.2 ONS 15454 IP Addressing Scenarios

4.2.1 Scenario 1: CTC and ONS 15454s on Same Subnet

4.2.2 Scenario 2: CTC and ONS 15454s Connected to Router

4.2.3 Scenario 3: Using Proxy ARP to Enable an ONS 15454 Gateway

4.2.4 Scenario 4: Default Gateway on CTC Computer

4.2.5 Scenario 5: Using Static Routes to Connect to LANs

4.2.6 Scenario 6: Static Route for Multiple CTCs

4.2.7 Scenario 7: Using OSPF

4.3 Viewing the ONS 15454 Routing Table


IP Networking


This chapter explains how to set up Cisco ONS 15454s in internet protocol (IP) networks and includes:

Scenarios showing Cisco ONS 15454s in common IP network configurations

Procedures for creating static routes

Procedures for using the Open Shortest Path First (OSPF) protocol

The chapter does not provide a comprehensive explanation of IP networking concepts and procedures.


Note To set up ONS 15454s within an IP network, you must work with a LAN administrator or other individual at your site who has IP networking training and experience. To learn more about IP networking, many outside resources are available. IP Routing Fundamentals, by Mark Sportack (Cisco Press, 1999), provides a comprehensive introduction to routing concepts and protocols in IP networks.


4.1 IP Networking Overview

ONS 15454s can be connected in many different ways within an IP environment:

They can be connected to LANs through direct connections or a router.

IP Subnetting can create ONS 15454 node groups, which allow you to provision non-DCC connected nodes in a network.

Different IP functions and protocols can be used to achieve specific network goals. For example, Proxy Address Resolution Protocol (ARP) enables one LAN-connected ONS 15454 to serve as a gateway for ONS 15454s that are not connected to the LAN.

You can create static routes to enable connections among multiple CTC sessions with ONS 15454s that reside on the same subnet but have different destination IP addresses.

If ONS 15454s are connected to OSPF networks, ONS 15454 network information is automatically communicated across multiple LANs and WANs.

4.2 ONS 15454 IP Addressing Scenarios

ONS 15454 IP addressing generally has seven common scenarios or configurations. Use the scenarios as building blocks for more complex network configurations. Table 4-1 provides a general list of items to check when setting up ONS 15454s in IP networks. Additional procedures for troubleshooting Ethernet connections and IP networks are provided in Chapter 9, "Ethernet Operation."

Table 4-1 General ONS 15454 IP Networking Checklist

Item
What to check

PC/workstation

Each CTC computer must have the following:

Netscape 4.61 or Internet Explorer 5.0 or higher

JRE 1.3.0_C (PC) or JRE 1.3.0_01 (Solaris) for Releases 2.2.2 or higher; JRE 1.2.2_05 or higher (Windows), or 1.2.2_03 or higher (Solaris) for Releases 2.2.1 or earlier

Modified Java policy file

See the "Computer Requirements" section on page 2-2 for additional information.

Link integrity

Link integrity exists between:

CTC computer and network hub/switch

ONS 15454s (backplane wire-wrap pins or RJ-45 port) and network hub/switch

Router ports and hub/switch ports

ONS 15454 hub/switch ports

Set the hub or switch port that is connected to the ONS 15454 to 10 Mbps half-duplex.

Ping

Ping the node to test connections between computers and ONS 15454s.

IP addresses/subnet masks

ONS 15454 IP addresses and subnet masks are set up correctly.

Optical connectivity

ONS 15454 optical trunk ports are in service; DCC is enabled on each trunk port


4.2.1 Scenario 1: CTC and ONS 15454s on Same Subnet

Scenario 1 shows a basic ONS 15454 LAN configuration ( Figure 4-1). The ONS 15454s and CTC computer reside on the same subnet. All ONS 15454s connect to LAN A, and all ONS 15454s have DCC connections.


Note Instructions for creating DCC connections are provided in "SONET Topologies" within the BLSR, UPSR and linear ADM procedures.


Figure 4-1 Scenario 1: CTC and ONS 15454s on same subnet

4.2.2 Scenario 2: CTC and ONS 15454s Connected to Router

In Scenario 2 the CTC computer resides on a subnet (192.168.1.0) and attaches to LAN A ( Figure 4-2). The ONS 15454s reside on a different subnet (192.168.2.0) and attach to LAN B. A router connects LAN A to LAN B. The IP address of router interface A is set to LAN A (192.168.1.1), and the IP address of router interface B is set to LAN B (192.168.2.1).

On the CTC computer, the default gateway is set to router interface A. If the LAN uses DHCP (Dynamic Host Configuration Protocol), the default gateway and IP address are assigned automatically. In the Figure 4-2 example, a DHCP server is not available.

Figure 4-2 Scenario 2: CTC and ONS 15454s connected to router

4.2.3 Scenario 3: Using Proxy ARP to Enable an ONS 15454 Gateway

Scenario 3 is similar to Scenario 1, but only one ONS 15454 (node #1) connects to the LAN ( Figure 4-3). Two ONS 15454s (#2 and #3) connect to ONS 15454 #1 through the SONET DCC. Because all three ONS 15454s are on the same subnet, Proxy ARP enables ONS 15454 #1 to serve as a gateway for ONS 15454s #2 and #3.

Figure 4-3 Scenario 3: Using Proxy ARP

ARP matches higher-level IP addresses to the physical addresses of the destination host. It uses a lookup table (called ARP cache) to perform the translation. When the address is not found in the ARP cache, a broadcast is sent out on the network with a special format called the ARP request. If one of the machines on the network recognizes its own IP address in the request, it sends an ARP reply back to the requesting host. The reply contains the physical hardware address of the receiving host. The requesting host stores this address in its ARP cache so that all subsequent datagrams (packets) to this destination IP address can be translated to a physical address.

Proxy ARP enables one LAN-connected ONS 15454 to respond to the ARP request for ONS 15454s not connected to the LAN. (ONS 15454 Proxy ARP requires no user configuration.) For this to occur, the DCC-connected ONS 15454s must reside on the same subnet. When a LAN device sends an ARP request to an ONS 15454 that is not connected to the LAN, the gateway ONS 15454 returns its MAC address to the LAN device. The LAN device then sends the datagram for the remote ONS 15454 to the MAC address of the proxy ONS 15454. The proxy ONS 15454 uses its routing table to forward the datagram to the non-LAN ONS 15454. The routing table is built using the OSPF IP routing protocol. (An OSPF example is presented in Scenario 6.)

4.2.4 Scenario 4: Default Gateway on CTC Computer

Scenario 4 is similar to Scenario 3, but nodes #2 and #3 reside on different subnets, 192.168.2.0 and 192.168.3.0, respectively ( Figure 4-4). Node #1 and the CTC computer are on subnet 192.168.1.0. The network includes different subnets because Proxy ARP is not used. In order for the CTC computer to communicate with ONS 15454s #2 and #3, ONS 15454 #1 is entered as the default gateway on the CTC computer using the "Direct Connections to the ONS 15454" section on page 2-5.

Figure 4-4 Scenario 4: Default gateway on a CTC computer

4.2.5 Scenario 5: Using Static Routes to Connect to LANs

Static routes are used for two purposes:

To connect ONS 15454s to CTC sessions on one subnet connected by a router to ONS 15454s residing on another subnet. (These static routes are not needed if OSPF is enabled. Scenario 7 shows an OSPF example.)

To enable multiple CTC sessions among ONS 15454s residing on the same subnet. (Scenario 6 shows an example.)

In Figure 4-5, one CTC residing on subnet 192.168.1.0 connects to a router through interface A. (The router is not set up with OSPF.) ONS 15454s residing on subnet 192.168.2.0 are connected through ONS 15454 #1 to the router through interface B. Proxy ARP enables ONS 15454 #1 as a gateway for ONS 15454s #2 and #3. To connect to CTC computers on LAN A, a static route is created on ONS 15454 #1.

Figure 4-5 Scenario 5: Static route with one CTC computer used as a destination

The destination and subnet mask entries control access to the ONS 15454s:

If a single CTC computer is connected to router, enter the complete CTC "host route" IP address as the destination with a subnet mask of 255.255.255.255.

If CTC computers on a subnet are connected to router, enter the destination subnet (in this example, 192.168.1.0) and a subnet mask of 255.255.255.0.

If all CTC computers are connected to router, enter a destination of 0.0.0.0 and a subnet mask of 0.0.0.0. Figure 4-6 shows an example.

The IP address of router interface B is entered as the next hop, and the cost (number of hops from source to destination) is 2.

Figure 4-6 Scenario 5: Static route with multiple LAN destinations

Procedure: Create a Static Route

Use the following steps to create a static route.


Step 1 Log into the ONS 15454 and select the Provisioning > Network tabs.

Step 2 Click the Static Routing tab. Click Create.

Step 3 In the Create Static Route dialog box enter the following:

Destination—Enter the IP address of the computer running CTC. To limit access to one computer, enter the full IP address (in the example, 192.168.1.100). To allow access to all computers on the 192.168.1.0 subnet, enter 192.168.1.0 and a subnet mask of 255.255.255.0. You can enter a destination of 0.0.0.0 to allow access to all CTC computers that connect to the router.

Mask—Enter a subnet mask. If the destination is a host route (i.e., one CTC computer), enter a 32-bit subnet mask (255.255.255.255). If the destination is a subnet, adjust the subnet mask accordingly, for example, 255.255.255.0. If the destination is 0.0.0.0, enter a subnet mask of 0.0.0.0 to provide access to all CTC computers.

Next Hop—Enter the IP address of the router port (in this example, 192.168.90.1) or the node IP address if the CTC computer is connected to the node directly.

Cost—Enter the number of hops between the ONS 15454 and the computer. In this example, the cost is two, one hop from the ONS 15454 to the router and a second hop from the router to the CTC workstation.

Step 4 Click OK. Verify that the static route displays in the Static Route window, or ping the node.


4.2.6 Scenario 6: Static Route for Multiple CTCs

Scenario 6 shows a static route used when multiple CTC computers need to access ONS 15454s residing on the same subnet ( Figure 4-7). In this scenario, CTC #1 and #2 and all ONS 15454s are on the same IP subnet; ONS 15454 #1 and CTC #1 are attached to LAN A. ONS 15454 #2 and CTC #2 are attached to LAN B. Static routes are added to ONS 15454 #1 pointing to CTC #1, and to ONS 15454 #2 pointing to CTC #2. The static route is entered from the node's perspective.

Figure 4-7 Scenario 6: Static route for multiple CTCs

4.2.7 Scenario 7: Using OSPF

Open Shortest Path First (OSPF) is a link state Internet routing protocol. Link state protocols use a "hello protocol" to monitor their links with adjacent routers and to test the status of their links to their neighbors. Link state protocols advertise their directly-connected networks and their active links. Each link state router captures the link state "advertisements" and puts them together to create a topology of the entire network or area. From this database, the router calculates a routing table by constructing a shortest path tree. Routes are continuously recalculated to capture ongoing topology changes.

ONS 15454s use the OSPF protocol in internal ONS 15454 networks for node discovery, circuit routing, and node management. You can enable OSPF on the ONS 15454s so that the ONS 15454 topology is sent to OSPF routers on a LAN. Advertising the ONS 15454 network topology to LAN routers eliminates the need to manually enter static routes for ONS 15454 subnetworks. Figure 4-8 shows the same network enabled for OSPF. Figure 4-9 shows the same network without OSPF. Static routes must be manually added to the router in order for CTC computers on LAN A to communicate with ONS 15454 #2 and #3 because these nodes reside on different subnets.

OSPF divides networks into smaller regions, called areas. An area is a collection of networked end systems, routers, and transmission facilities organized by traffic patterns. Each OSPF area has a unique ID number, known as the area ID, that can range from 0 to 4,294,967,295. Every OSPF network has one backbone area called "area 0." All other OSPF areas must connect to area 0.

When you enable ONS 15454 OSPF topology for advertising to an OSPF network, you must assign an OSPF area ID to the ONS 15454 network. Coordinate the area ID number assignment with your LAN administrator. In general, all DCC-connected ONS 15454s are assigned the same OSPF area ID.

Figure 4-8 Scenario 7: OSPF enabled

Figure 4-9 Scenario 7: OSPF not enabled

Use the following procedure to enable OSPF on each ONS 15454 node that you want included in the OSPF network topology. ONS 15454 OSPF settings must match the router OSPF settings, so you will need to get the OSPF Area ID, Hello and Dead intervals, and authentication key (if OSPF authentication is enabled) from the router to which the ONS 15454 network is connected before enabling OSPF.

Procedure: Set up OSPF


Step 1 Log into the ONS 15454 node.

Step 2 In node view, select the Provisioning > Network > OSPF tabs. The OSPF pane has several options ( Figure 4-10).

Figure 4-10 Enabling OSPF on the ONS 15454

Step 3 On the top left side, complete the following:

DCC OSPF Area ID—Enter the number that identifies the ONS 15454s as a unique OSPF area. The OSPF area number can be an integer between 0 and 4294967295, and it can take a form similar to an IP address. The number must be unique to the LAN OSPF area.

DCC Metric—This value is normally unchanged. It sets a "cost" for sending packets across the DCC, which is used by OSPF routers to calculate the shortest path. This value should always be higher than the LAN metric. The default DCC metric is 100.

Step 4 In the OSPF on LAN area, complete the following:

OSPF active on LAN—When checked, enables ONS 15454 OSPF topology to be advertised to OSPF routers on the LAN. Enable this field on ONS 15454s that directly connect to OSPF routers.

Area ID for LAN Port—Enter the OSPF area ID for the router port where the ONS 15454 is connected. (This number is different from the DCC Area ID.)

Step 5 In the Authentication area, complete the following:

Type—If the router where the ONS 15454 is connected uses authentication, select Simple Password. Otherwise, select No Authentication.

KeyIf authentication is enabled, enter the OSPF key (password).

Step 6 In the Priority and Intervals area, complete the following:

The OSPF priority and intervals default to values most commonly used by OSPF routers. In the Priority and Invervals area, verify that these values match those used by the OSPF router where the ONS 15454 is connected.

Router Priority—Used to select the designated router for a subnet.

Hello Interval (sec)—Sets the number of seconds between OSPF "hello" packet advertisements sent by OSPF routers. Ten seconds is the default.

Dead Interval—Sets the number of seconds that will pass while an OSPF router's packets are not visible before its neighbors declare the router down. Forty seconds is the default.

Transit Delay (sec)—Indicates the service speed. One second is the default.

Retransmit Interval (sec)—Sets the time that will elapse before a packet is resent. Five seconds is the default.

LAN MetricSets a "cost" for sending packets across the LAN. This value should always be lower than the DCC metric. Ten is the default.

Step 7 In the OSPF Area Range Table area, complete the following:

Area range tables consolidate the information that is propagated outside an OSPF Area border. One ONS 15454 in the ONS 15454 OSPF area is connected to the OSPF router. An area range table on this node points the router to the other nodes that reside within the ONS 15454 OSPF area.

To create an area range table:

a. Under OSPF Area Range Table, click Create.

b. In the Create Area Range dialog box, enter the following:

Range Address—Enter the area IP address for the ONS 15454s that reside within the OSPF area. For example, if the ONS 15454 OSPF area includes nodes with IP addresses 10.10.20.100, 10.10.30.150, 10.10.40.200, and 10.10.50.250, the range address would be 10.10.0.0.

Range Area ID—Enter the OSPF area ID for the ONS 15454s. This is either the ID in the DCC OSPF Area ID field or the ID in the Area ID for LAN Port field.

Mask Length—Enter the subnet mask length. In the Range Address example, this is 16.

Advertise—Check if you want to advertise the OSPF range table.

c. Click OK.

Step 8 All OSPF areas must be connected to Area 0. If the ONS 15454 OSPF area is not physically connected to Area 0, use the following steps to create a virtual link table that will provide the disconnected area with a logical path to Area 0:

a. Under OSPF Virtual Link Table, click Create.

b. In the Create Virtual Link dialog box, complete the following fields (OSPF settings must match OSPF settings for the ONS 15454 OSPF area):

Neighbor—Enter the router ID of the Area 0 router.

Transit Delay (sec)—The service speed. One second is the default.

Hello Int (sec)—The number of seconds between OSPF "hello" packet advertisements sent by OSPF routers. Ten seconds is the default.

Auth Type—If the router where the ONS 15454 is connected uses authentication, select Simple Password. Otherwise, set it to No Authentication.

Retransmit Int (sec)—Sets the time that will elapse before a packet is resent. Five seconds is the default.

Dead Int (sec)—Sets the number of seconds that will pass while an OSPF router's packets are not visible before its neighbors declare the router down. Forty seconds is the default.

c. Click OK.

Step 9 After entering ONS 15454 OSPF area data, click Apply.

If you changed the Area ID, the TCC+ cards will reset, one at a time.


4.3 Viewing the ONS 15454 Routing Table

ONS 15454 routing information is displayed on the Maintenance > Routing Table tabs ( Figure 4-11). The routing table provides the following information:

Destination—Displays the IP address of the destination network or host.

Mask—Displays the subnet mask used to reach the destination host or network.

Gateway—Displays the IP address of the gateway used to reach the destination network or host.

Usage—Shows the number of times this route has been used.

Interface—Shows the ONS 15454 interface used to access the destination. Values are:

cpm0—the ONS 15454 Ethernet interface, that is, the RJ-45 jack on the TCC+ and the LAN 1 pins on the backplane.

pdcc0—an SDCC interface, that is, an OC-N trunk card identified as the SDCC termination.

lo0—a loopback interface

Figure 4-11 Viewing the ONS 15454 routing table

Table 4-2 shows sample routing entries for an ONS 15454.

Table 4-2 Sample Routing Table Entries

Entry
Destination
Mask
Gateway
Interface

1

0.0.0.0

0.0.0.0

172.20.214.1

cpm0

2

172.20.214.0

255.255.255.0

172.20.214.92

cpm0

3

172.20.214.92

255.255.255.255

127.0.0.1

lo0

4

172.20.214.93

255.255.255.255

0.0.0.0

pdcc0

5

172.20.214.94

255.255.255.255

172.20.214.93

pdcc0


Entry #1 shows the following:

Destination (0.0.0.0) is the default route entry. All undefined destination network or host entries on this routing table will be mapped to the default route entry.

Mask (0.0.0.0) is always 0 for the default route.

Gateway (172.20.214.1) is the default gateway address. All outbound traffic that cannot be found in this routing table or is not on the node's local subnet will be sent to this gateway.

Interface (cpm0) indicates that the ONS 15454 Ethernet interface is used to reach the gateway.

Entry #2 shows the following:

Destination (172.20.214.0) is the destination network IP address.

Mask (255.255.255.0) is a 24-bit mask, meaning all addresses within the 172.20.214.0 subnet can be a destination.

Gateway (172.20.214.92) is the gateway address. All outbound traffic belonging to this network is sent to this gateway.

Interface (cpm0) indicates that the ONS 15454 Ethernet interface is used to reach the gateway.

Entry #3 shows the following:

Destination (172.20.214.92) is the destination host IP address.

Mask (255.255.255.255) is a 32 bit mask, meaning only the 172.20.214.92 address is a destination.

Gateway (127.0.0.1) is a loopback address. The host directs network traffic to itself using this address.

Interface (lo0) indicates that the local loopback interface is used to reach the gateway.

Entry #4 shows the following:

Destination (172.20.214.93) is the destination host IP address.

Mask (255.255.255.255) is a 32 bit mask, meaning only the 172.20.214.93 address is a destination.

Gateway (0.0.0.0) means the destination host is directly attached to the node.

Interface (pdcc0) indicates that a SONET SDCC interface is used to reach the destination host.

Entry #5 shows a DCC-connected node that is accessible through a node that is not directly connected:

Destination (172.20.214.94) is the destination host IP address.

Mask (255.255.255.255) is a 32-bit mask, meaning only the 172.20.214.94 address is a destination.

Gateway (172.20.214.93) indicates that the destination host is accessed through a node with IP address 172.20.214.93.

Interface (pdcc0) indicates that a SONET SDCC interface is used to reach the gateway.