There is no set limit on the number of PVCs (subinterfaces) the NetVanta 3200 can terminate, but the best performance will be obtained on units where the total does not exceed one hundred thirty (130).

Routing is a straightforward process. Either the router has a route to a remote network or it sends the packet to its default route. Try to determine where the routing fails. You can use the traceroute command from the privileged prompt to see what is the last gateway a packet gets to. Also the ping command will help. Ping along the route until a response is not received. Next, ensure the router where pings fail is configured properly. That is:

• If not already set, enable IP routing (on by default). All interfaces need IP addresses or unnumbered references. If statically routing, configure static routes on both far & near router as well as the default route. (e.g. ip route 0.0.0.0 0.0.0.0 A.B.C.D where A.B.C.D. is the far-end WAN address)
• RIP routing must be configured if dynamically routing. Far and near routers need to have all network numbers included under the RIP configuration:

  Router(config)# router ripRouter(config-rip)# version 2Router(config-rip)# network 192.168.1.0 255.255.255.0 ! WAN networkRouter(config-rip)# network 192.168.20.0 255.255.255.0 ! LAN

  Router(config-rip)# passive-interface ethernet 0/1

• Passive disables rip broadcasts on the local Ethernet.

Now check the routing table:

Here the router lists all the places it knows how to get to. It does not however know if those remote gateways know how to get back to the network where the ping is originating. Imagine that the workstation on 192.168.20.3 tries to ping a workstation on 192.168.30.5. Assuming that the pings are successful from 20.3 to 192.168.1.2, we should check the far-end router. If it shows a route to 20.0 and to 30.0, we need to find out if the 30.0 router has a default route to 10.0 or has a route to 20.0. If it does then the configuration of the far-end workstation should be checked for a valid default gateway.

Passwords cannot be hidden in the configuration file. They can be encrypted so they are not readily obtained from the configuration file. To encrypt your passwords use the following command:

The password is encrypted with the md5-hashing scheme and does not appear in clear text in the configuration file. Remember to save with the "copy run start" command.

The NetVanta 3200 will require direct physical access to bypass the configured password for privileged mode. This procedure cannot be used remotely over Telnet. First, connect a terminal session cable to the console port on the NetVanta 3200. Establish a connection by using settings: 9600 bps, 8 bits, no parity, and 1 stop bit. Reboot the NetVanta 3200 by using the reload command in privileged mode or by simply repowering the unit. As the unit boots, you will be given the opportunity to break out into monitor mode by pressing the ESC key within 5 seconds. While in the monitor mode issue the following command:

Notice that you are not issuing the reboot command following the bypass command. Once bypassed, the enable or privileged mode is accessible by entering enable <cr>. You will not be challenged for the password. Once in the privileged mode, you can enter a new password with the "enable password <word>" command where <word> is the new password. Also remember to change telnet passwords if they are also affected.

Router troubleshooting need not be difficult if a systematic approach is used. First try to generalize the issue to discern if the problem can be localized. For instance, if data is flowing slowly is it also slow between devices on the LAN? Dividing the problem simplifies troubleshooting. If a remote workstation cannot be pinged, can the remote router be pinged? How about the local router?

Once the problem is isolated, try to identify which of the three networking layers appears to be affected. If there is a physical layer issue, it does not make sense to solve a network layer routing symptom first. When in doubt, start at the physical layer. Next troubleshoot the link layer, then finally the network layer.

The first command to use is "show interface ppp 1." This command lists the current state of the ppp link as shown below:

The link state or LCP here shows that at least the link is functional. If bridging or IP had been configured the NCP (Bridge or IPCP) layer would have gone active. If the LCP was inactive, the configuration should be checked to ensure it is correct for this physical link. Sometimes it is helpful to debug the ppp function to determine what is going wrong. Also, the security settings (CHAP, PAP, or NONE) should be correct at both ends. Try disabling security at both ends to see if configuration could be the issue.

To setup the router for listening, but no RIP transmitting on an interface enter the following command in router rip configuration mode:Router(config rip)# passive-interface ethernet 0/1

If you want to stop transmitting on another interface simply replace ethernet 0/1 in the above command with the appropriate frame relay or PPP virtual interface name (e.g. fr 1.16, ppp 1, etc)

Should you ever need to upgrade your unit, several steps need to be taken to assure a valid upgrade. First, save your existing configuration to a tftp server. The command to execute this step is "copy start tftp." You will be prompted for file names and the server address in the process. Next, download the latest AOS software from the ADTRAN support website. When properly installed on your tftp server, the file will have the form "01010X.biz" where X is the latest version number. The release file is 010100.biz. From your privileged prompt:

During the tftp download you will be prompted for the tftp server name, the tftp server file name, and finally the name of the file once it is transferred to the on-board flash. The flash can hold up to eight megabytes of files, whether AOS or configuration files. Now from the Configuration prompt:

The boot command tells the router which software on the flash to use as the boot up AOS. The router should now be rebooted with the privileged command "reload." When the unit reboots, it will be running the latest software.

To setup an interface for V2 listening only, first go to the interface configuration mode:Router(config-eth 0/1)# ip rip receive version 2

The command shown instructs the interface to only listen for V2 advertisements.

A router can be used in one of two modes: it can be setup in a host mode, or it can be used as a router. First, let's consider host mode operation. Host mode is useful when first sending the router to a remote site for installation and configuration, providing Telnet access to the device. The host mode resembles a plain workstation and requires an IP host address as well as a default gateway. The default gateway is where the device will send packets not on the subnet defined by the host address and mask. Now consider the operation in router mode. The router has a similar set of decisions but over a wider number of interfaces. First, the router must determine if the incoming packet is destined for that router, one of the attached interfaces, or some other network. So the default route (defined by the static route command " ip route 0.0.0.0 0.0.0.0 A.B.C.D" where A.B.C.D. is the address of the far end router serving as the gateway for all unknown route packets) if configured, serves as the destination for packets that a route is not known for. If the default route is learned through a routing protocol, it is also known as the gateway of last resort.

How you chose to route with the NetVanta 3200 is a result of several input factors. First, decide if the bandwidth to the NetVanta 3200 is large enough to support a routing protocol. Usually, at least 128Kbps is sufficient to support V1 or V2. Next decide whether RIP V1 is already supported in your network. If no other V1 is in use, simply use V2 since bandwidth requirements are similar, and V2 offers greater flexibility with respect to subnets. On low bandwidth circuits or in situations where static routes are already being redistributed, use Static Routes to forward traffic to remote networks.

Frame relay is a polled-response protocol. If the physical layer like the T1 is up, the NetVanta 3200 should poll the frame relay switch, and get a response back every ten seconds.

The following is the output of a show frame-relay lmi command:

This command tells us we are polling the switch and that it is responding. The "clear counters" command will let you clear these statistics and evaluate what is happening. Once you determine the LMI is fine, you need to determine if the far end is up and the local DLCI active. An inactive DLCI means the far end is down, deleted means the local DLCI is wrong or not working. To do this use the "show frame-relay pvc" command and evaluate the output:

If you plan on providing Telnet access to your NetVanta 3200 you MUST set a Telnet password. Use the following commands to enable Telnet on the virtual console interfaces while in configuration mode:

Where <word> is the password you wish to use for Telnet. The Telnet password cannot be encrypted at this time.

The NetVanta 3200 has several Network Interface Modules (NIMs) to support various services. The T1 NIM is normally used with a ESF/B8ZS full or fractional T1 service. The T1 can be used for access to a frame relay provider or may be a dedicated point-point circuit. Normally, frame service is used for service over longer distances (also called inter-LATA). Dedicated or point-point T1 service is most cost effective for intra-LATA (within a city or town) traffic. Additionally, a DDS NIM is available for 56 or 64Kbps access service. This transport can also be used for frame relay or point-point services. Finally, a V.35 or Serial NIM is available for connection to SMDS, ATM, or other access service for point-point or frame access.

Setting up the NetVanta 3200 for host mode is very easy. First, erase any configuration in the router by issuing the "erase start" command at the privileged prompt. Reload the router. Next disable IP routing by issuing the "no ip routing" command. Next assign an ethernet IP address and "no shut" the ethernet interface. Finally, enter a default gateway as shown below. Do NOT use the gateway of last resort or default route since this command is only useful in the router mode (e.g. x.x.x.x 0.0.0.0 0.0.0.0 a.b.c.d.).

Where a.b.c.d is the router's directly connected interface that will serve as the default gateway for the NetVanta 3200.

A router is useful to divide high traffic networks into smaller, logical entities. The bridge also divides networks for the purpose of making them more efficient. The difference is that the bridge does its dividing based on the MAC or layer 2 address, and the router divides based on IP or layer 3 address. So the router divides broadcast domains, and the bridge (or switch) divides the collision domain. As the previous definition implies, the collision domain is that collection of wiring and devices that all contend for the same bandwidth. Consider that we start a company and connect all our workstations and servers to a series of hubs. As the company grows, and finally expands to a second building we notice that our traffic is growing slower. A bridge is selected to connect the 2 buildings together. Since a bridge divides the collision domain each building gets its own 100 Megabit LAN to share among that building's computers. If any Ethernet frame is destined for the other building it is forwarded through the bridge. The bridge learns which computer (MAC address) is in each building. So traffic from one building does not affect the other – except for broadcasts. As broadcasts in the 2-building network grow we replace our bridge with a router. All the computers in each building need to be given an IP address in that building's own unique network. No broadcasts are sent between building because the router divides the broadcast domain.

So:

If you need to add a building or remote network to your building and only routable protocols like IP are on the LANs, use a router. Lower bandwidth links can be used between locations increasing efficiency. If only a few non-routable protocols are also being used consider setting up simple bridging where IP is routed and all other protocols are bridged. The NetVanta 3200 supports this mode of operation. Finally, if only non-routable protocols are in use, or ample bandwidth is available and simplicity is needed (simple LAN joining desired), use a bridge.

First, review the T1 settings. The defaults expect the incoming T1 to be ESF/B8ZS. The defaults also assume that the timing source for the system is the network. Also ensure that the T1 interface is administratively up by issuing the "no shut"command in T1 interface configuration mode. If the T1 is still not active, connect a loopback plug in the T1 RJ-45 jack. While in T1 interface configuration mode, enter the command "test QRSS." Next, while still in T1 interface configuration mode enter "test clear." Let the test run for a minute or so and then enter "show QRSS." The count should be 0 indicating no errors while in loop. To verify QRSS is working you may wish to use the "test insert" command to inject a single error, and use the "show QRSS" command to see the single error injected. If the interface becomes active with no errors, you may safely assume there is an issue with the Telco circuit. If there are errors on a valid loopback the NIM may need to be repaired. The show interface t1 1/1 should look like:

A router like the NetVanta 3200 is used to properly send Internet Protocol ( IP, the language of the Internet) packets from one location (network) to another. The router is capable of terminating a broadcast domain, effectively allowing high traffic IP areas to be divided into separate, lower traffic logical entities called networks. Each of these networks is assigned a unique IP address of the form A.B.C.D. Part of each network address is the subnet mask. The mask is used to determine which of the 32 bits in the address are used to identify networks, and which are used to determine the host address. In the IP address 192.168.10.1 mask 255.255.255.0, the first three bytes (all 255, or ff – hex, 11111111 binary) of the mask indicate that the first three bytes of the address are the network part. Therefore the unique network number in this system is 192.168.10.0. The address also indicates that this address is #1 of 254 possible host addresses.

IP (Internet Protocol) addresses should be assigned logically and in a fashion to simplify the routing task. IP addresses come in two types: public and private. Public addresses are purchased from an Internet Service Provider (ISP) and are required for operation to and from the world wide Internet. Private addresses are not routed on the Internet and consist of three ranges: class A network 10.0.0.0/8, class B networks 172.16.0.0/12 and class C network 192.168.0.0/16. The simplest of these are the class C networks. They allow up to 254 host addresses on a single network and require no specialized subnetting. So the networks 192.168.1.0 – 192.168.254.0 with the default mask 255.255.255.0 are available for internal use. Try to use adjacent networks when possible in order to summarize if necessary. As an example:

Several books are available on basic networking. These texts can provide further information on subnetting, which is needed for using the large class A 10.0.0.0 network. Also they discuss the concept of NAT or Network Address Translation. Many companies internally use private addresses and use a firewall/router like the ADTRAN 2100 to map to one or more public addresses on a shared basis. The advantages of this approach include: protecting the identity of the workstations from Internet hackers, decreasing the cost of Internet access by using fewer public addresses, and providing access control of Internet resources.

A VT 100 terminal emulator is a software package that allows an end-user to communicate with a DCE device (data communications equipment) locally or remotely. A VT 100 terminal emulator can be used to configure the NetVanta 3200 router products by issuing configuration commands directly to the unit. The proper default setting for the terminal program port setup is 9600 bps, 8 data bits, no parity bits, and one stop bit. Please refer to the User Manual for more information about the VT 100 terminal menu.