To configure physical settings on the LAG, this is found under Switch > Ports > LAG Configuration. To configure VLAN settings on the LAG, navigate to Switch > VLAN > LAG settings. To configure Spanning Tree settings on the LAG, navigate to Switch > Spanning Tree > STP LAG Settings.
Virtual link trunking (VLT) allows physical links between two Dell switches to appear as a single virtual link to the network core or other. switches such as Edge, Access, or top-of-rack (ToR). As a result, the two physical switches appear as a single switch to the connected. devices.
Link Aggregation Control Protocol
In order to check to see how long the port is in Up or Down status, use the show interfaces [interface id] command. In the example, under the show interfaces FastEthernet0/1 command, look at a line that shows something such as: Last input 00:00:41, output 00:00:00, output hang never.
etherchannel summary command
The basic process for configuring your EtherChannel interfaces is as follows:
- Connect to the command-line interface (CLI) your switch.
- Access Privileged EXEC mode.
- Access Global Configuration mode.
- Access Interface Configuration mode.
- Change switchport to trunk or access, but all ports must be in the same VLAN.
PO1 is the etherchannel interface - Port channel interface. You can use Po1 interface as Layer 2 or Layer 3 interface incase of L3 you can assign IP to Po1 interface. Po interface represnts the channel, the grouped interfaces bye.
Verifying and Troubleshooting EtherChannelThere are a number of commands to verify an EtherChannel configuration. First, the show interface port-channel command displays the general status of the port channel interface. In Figure 1, the Port Channel 1 interface is up.
Port channel vs Etherchannel –
| PARAMETER | PORT CHANNEL | ETHERCHANNEL |
|---|
| Cisco's way of distinguishing | Port-channel is the name of Cisco's virtual interface for the purpose of Link aggregation | Etherchannel is a term used by Cisco to describe a link aggregation |
Etherchannel traffic distribution can be tested with the test etherchannel …command. This simulates which link in a port-channel will be used for a particular flow. Below is the example for IP based traffic, however there are other options such as MAC address that can be specified.
logical port-channel interface
A port channel is a communication link between two switches supported by matching channel group interfaces on each switch. A port channel is also referred to as a Link Aggregation Group (LAG). Port channels combine the bandwidth of multiple Ethernet ports into a single logical link.
When configuring Layer 2 EtherChannels, follow these guidelines:
- Assign all ports in the EtherChannel to the same VLAN, or configure them as trunks.
- If you configure an EtherChannel from trunk ports, verify that the trunking mode (ISL or IEEE 802.1Q) is the same on all the trunks.
The Port-Channel interface numbers are locally-significant only. On the 2960, the number can be anything between 1 and 6, and they do not have to match end to end. If it is possible, use the same number on both sides of a port-channel so that coordinating troubleshooting is less complicated.
Trunking and port channels function as follows: Port channels enable several physical links to be combined into one aggregated logical link. Trunking enables a link to carry (trunk) multiple VLAN traffic.
There is no way to delete a port channel. If you make it untrusted (the default confguration of a port channel) and no interfaces are assigned to it, it will go away.
LACP uses the port priority to decide which ports should be put in standby mode when there is a hardware limitation that prevents all compatible ports from aggregating. LACP also uses the port priority with the port number to form the port identifier. The default value is automatically set to 32768.
A port-channel can be configured to work as a Layer 2 port-channel or a Layer 3 port-channel. Based on the configuration mode of port-channel, it can allow configuring the respective properties like a Layer 2 port-channel can be configured as an access port or as a trunk port.
EtherChannel and IEEE 802.3ad standards are very similar and accomplish the same goal. EtherChannel supports both LACP and Cisco's PAgP, whereas 802.3ad uses LACP. LACP allows for up to 8 active and 8 standby links, whereas PAgP only allows for 8 active links.
LACP runs on any link that is configured to be in the active state. The port in an active mode also automatically initiates negotiations with other ports by initiating LACP packets. Passive mode—the interface is not in an active negotiating state. LACP runs on any link that is configured in a passive mode.
What are two requirements to be able to configure an EtherChannel between two switches? (Choose two.)
- The interfaces that are involved need to be contiguous on the switch.
- All the interfaces need to work at the same speed.
- All the interfaces need to be working in the same duplex mode.
switchport nonegotiate: Prevents the interface from generating DTP frames. You can use this command only when the interface switchport mode is access or trunk. You must manually configure the neighboring interface as a trunk interface to establish a trunk link.
Traffic in a port channel is distributed across the individual bundled links in a deterministic fashion. However, the load is not necessarily balanced equally across all of the links.
You can assign up to 16 physical interfaces to an EtherChannel but only 8 interfaces will be active at a time. If you want to configure an EtherChannel then we have three options: PAgP (Cisco proprietary)
A layer 3 etherchannel is similar to an interface on a router. The switch won't “switch” traffic on this interface but route it. Because it's a layer 3 interface, we configure an IP address on it. If you forget to run the no switchport command on an interface, your etherchannel will be layer 2 instead of layer 3!
You configure the load balancing and forwarding method with use of the port-channel load-balance {dst-ip | dst-mac | src-dst-ip | src-dst-mac | src-ip | src-mac} global configuration command. You can find out which interface is used in the EtherChannel to forward traffic based on the load balancing method.
