A switch allows each connected device to have dedicated bandwidth instead of shared bandwidth. Note: The Portfast feature must never be used on switch ports that connect to other switches or hubs or routers. CS: Lab 7-3: Testing Mode: Connect a Computer to a Network. This is because when you understand the basics of MLSP you get at the heart of MLS, and this is essential to effectively troubleshoot the MLS. Try to work with the switch software first. Remember that the point of MLS is to create a shortcut between two VLANs, so that the routing between the two end devices can be performed by the switch, and this frees the router for other tasks. An Ethernet crossover cable is used for switch to switch or hub to switch connections.
Single mode fiber generally reaches 10 kilometers, and multi-mode fiber can usually reach 2 kilometers, but there is the special case of 100BaseFX multi-mode used in half-duplex mode, which can only go 400 meters. The initial connectivity delay is also frequently seen in a switched environment in which a network administrator updates software or drivers. Lab 7-3 testing mode connect a computer to a network adapter. MLSP also allows the MLS-SE to learn the Media Access Control (MAC, layer-two) addresses of the MLS-enabled router interfaces, check the flowmask of the MLS-RP (explained later in this document), and confirm that the MLS-RP is operational. Note: Technically, the listening and learning stage is both be 15 seconds, which is how the forward delay parameter is set for this VLAN. Go to the Support and Documentation web site to get detailed support information by specific products or technologies. Image text-base: 0x00003000, data-base: 0x00259AEC. This example also shows that a link can be successfully connected when there is a mismatch in the duplex modes.
These categories are explored a little deeper. Each flow is unidirectional; communication between PCs, for example, requires the setup and use of two shortcuts. Do not just swap it with any other cable; make sure that you swap it with a cable that you know is good and is of the correct type. The software configuration guides give you background information about what the feature does and what commands to use to configure it on your switch. If you do this with the power on, make sure the module is hot swappable. The default of most Cisco switches is to have a port in notconnect state, which means that it is currently not connected to anything, but it wants to connect. The switch does not actually route; it rewrites the frames so that it appears to the end devices that they talk through the router. Change the speed on port 1/1 in Switch A to 10Mb. The status can be "connected" even if duplex has been incorrectly negotiated or misconfigured. The counters are visible with theshow maccommand. Mismatched Parameters. Building configuration...... spanning-tree portfast... Lab 7-3: testing mode: connect a computer to a network router. Now do the timing test with Portfast enabled. The pings began to fail.
Commands that generate this type of output on the Catalyst 4000/5000/6000 switches areshow portandshow mac. Lab 7-3: testing mode: connect a computer to a network services. If the destination MAC address is not in the CAM table (the address is unknown), the switch sends the frame out all other ports that are in the same VLAN as the received frame. Ping- to test connectivity to the other switch. The mismatch was caused by the 1/1 port of Switch B, which default to half-duplex because it sensed its Link Partner could no longer perform auto-negotiation. For fiber connections, make sure the transmit lead of one port is connected to the receive lead of the other port, and vice versa; transmit to transmit, receive to receive, does not work.
Note that the 4. x train has 'gone General Deployment (GD), ' or passed rigorous end-user criteria and field-experience targets for stability, so check the Cisco website for the latest releases. Since the switch decides on a frame by frame basis which ports exchange data, it is a natural extension to put logic inside the switch to allow it to choose ports for special groupings. The symptoms that you see in your network can be the result of problems in another area or layer. Trunking is a mechanism that is most often used to allow multiple VLANs to function independently across multiple switches.
The 1900 automatically saves the configuration after changes have been made. This location information is placed in a Content Addressable Memory table (CAM - named for the type of memory used to store these tables). Recertification for. Enter Selection: Timing Tests on the Catalyst 1900. Maximum distances for Ethernet or Fast Ethernet copper wires are 100 meters. Make sure that you have the correct cable for the type of connection that you make. Multilayer Switching (MLS). Dependent upon the physical connections involved, the frames can actually multiply exponentially due to the flooding algorithm, which can cause serious network problems. A flow diagram to use to troubleshoot basic IP MLS is included and discussed. Note: If you hard code the speed on a port, it disables all auto-negotiation functionality on the port for speed and duplex.
Also, after you turn on portfast, the elapsed time for the port to come up is already less than 1 second, so there is not much point to try to change speed/duplex negotiation settings to speed things up. The test then proceeds to turn portfast on and measure the time, then turn PAgP to off and measure the time, then turn trunking off and measure the time. Aside from what has already been mentioned, the most common cause of this error is when the switch learns multiple identical Ethernet Media Access Control (MAC) address within the same VLAN; Ethernet standards do not allow for identical MAC addresses within the same VLAN. This message is displayed on the console of SwitchB when the ports of SwitchA were disabled. 2/2 auto negotiate not-trunking 1... Switch-A (enable) set trunk 2/1-2 off.
A little lower in the output, the Transmit information (Xmit-Unicast) shows how SwitchA distributed the traffic across the channel to SwitchB. Valid EtherChannel configurations include these: Table 22-5: Valid EtherChannel Configurations. Last reset from power-on. There is a benefit to a physical loop in your network: it can provide redundancy. Both network-to-network and network-to-host. Now, if SwitchA drops out for some reason, or if new hardware replaces SwitchA, SwitchB tries to re-establish the channel. For MLS to work, be sure that VTP is enabled on the switch: set vtp enable.
The third major component of MLS is the Multilayer Switching Protocol (MLSP). Use Portfast and Other Commands to Fix End-Station Startup Connectivity Problems. Spanning tree type ieee. The Multilayer LAN Switches link leads you to documentation for all Cisco LAN switches. A switch can greatly increase the available bandwidth in your network, which can lead to improved network performance. It especially wants to know whether this port is part of a physical loop. Every time a link becomes active and moves to the forwarding state in spanning tree, the switch sends a special spanning tree packet called a Topology Change Notification (TCN). Duplex Mismatch: If the switch port receives a lot of late collisions, this usually indicates a duplex mismatch problem. Warning: Whenever you make configuration changes to a router intended to be permanent, remember to save those changes with acopy running-config starting-config(shortened versions of this command includecopy run startandwr mem). Shut down the port and repeat the test. 0 Model: WS-C5505 Serial #: 066507453. Not every Fast Ethernet module supports EtherChannel. The final result gives a time of2 seconds(0528 to 0530).
You can verify this happens with theshow maccommand. See the "Troubleshoot Ethernet 10/100Mb Half/Half/Full Duplex Auto-Negotiation" for additional information on the caveats of auto-negotiation. 2 24 WS-X5225R 012785227 Hw: 3. When you use the word layer, you refer to the 7-layer OSI model. Go to and under the section Service & Support, choose Technical Documents. Turn the devices off and back on again. In this case the total time was under1 second. The rest of the ports are significant, as well, because they connect the actual users of the network. LAN Switching Introduction. Note: Financial Aid Self Service scheduled to be released by Ellucian in Fall 2019*. A few essential assumptions are made: You are familiar with the basic configuration steps required to enable IP MLS on the router and switches and have completed these steps: see the resources listed at the end of this document for excellent material. In order to verify that traffic goes over all the ports in the channel, you can use theshow maccommand. The configuration of the switches has been cleared with the clear config all command. When an error is encountered while you configure EtherChannel, be sure to check the status of the ports after you correct the EtherChannel error situation.