Large-scale network connections create a lot of traffic between the links. Hence it is important to observe some protocols while establishing connections between different networks for the smooth operation of the overall connection grid.
Various parameters are taken into consideration while creating and implementing these network protocols.
Key Takeaways
- LACP is a standard protocol to bundle multiple physical links into a single logical link, while PAGP is a Cisco proprietary protocol used for the same purpose.
- LACP is an open protocol and can be used with any vendor’s equipment, while PAGP can only be used with Cisco equipment.
- LACP is a passive protocol, while PAGP is an active protocol that actively negotiates with other PAGP-capable devices to form a link aggregation group.
LACP vs PAgP
The difference between Cisco LACP and PAgP is the vendor connections and other third-party connections supported over these protocols. LACP offers an open-source connection that allows non-Cisco devices to connect to the network. PAgP is a proprietary protocol of Cisco, which allows only Cisco devices to access a particular network.

LACP is a protocol, that is, a set of rules for connecting various devices to a network and implementing the operation of these devices on the network.
Cisco created it to handle the network traffic generated after connecting non-Cisco devices to a Cisco network. This allowed for the easy functioning of the network.
PAgP is a proprietary control protocol developed by Cisco which can work only in a Cisco network, where only Cisco devices are used.
The protocol helps the network’s smooth operation by making the package transfer operation less time-consuming. The protocol is used to support a Cisco device-operated vendor network.
Comparison Table
Parameters of Comparison | LACP | PAgP |
---|---|---|
Operation Channel | EtherChannel and IEEE 802.3ad | EtherChannel |
Support over Vendors | It supports third-party device vendors as it is an open-source protocol | It can only support vendors using Cisco network devices as it is a Cisco proprietary product |
Created | IEEE 802.3ad authorized LACP in 2000 | Cisco PAgP was invented in the early 1990s |
Default operation | The default operation mode of LACP is Active | The default mode of operation of PAgP is Desirable |
Operation | LACP ports can only respond to requests but cannot send LACP packets | PAgP ports can respond to requests as well as send packets, but only to similar PAgP ports |
What is Cisco LACP?
Cisco LACP is an Ethernet connection protocol designed by Cisco. The protocol enables different Cisco switches and network devices to interact and manage Ethernet connections between other switches that operate on this protocol.
The protocol was developed to allow third-party switches to interact with Cisco switches, allowing these switches to operate on the same network.
As allowing different switches into the network would increase the network traffic, there was a need for a separate protocol to govern the switches’ functioning and manage the incoming traffic.
Thus a new set of rules was created for this purpose, conforming to the IEEE 802.3ad standards.
The protocol, known as Link Aggregation Control Protocol (LACP), was set according to the IEEE 802.3ad standard, and IEEE 802.3ad authorized it in the year 2000.
As the protocol was designed according to the IEEE 802.3ad standard, it allowed all the network devices conforming to the standard to operate on the Cisco network.
This allowed for more flexibility while making a network, as vendors using different devices could now request packages through a Cisco network, which was not possible earlier.
The configuration of the devices using the LACP protocol depends on the version of the device, and it can either be set to an “active” or “passive” state while operating.
What is Cisco PAgP?
Cisco PAgP is a Cisco proprietary protocol designed to aid in the management of network traffic in a Cisco switching network. The protocol is a proprietary product designed by Cisco, and it can only operate on a Cisco network.
The protocol was designed in the early 1990s to provide a set of rules for the proper functioning and operation of Cisco devices on a network.
The PAgP protocol works by implementing three modes of operation on devices on the network. “Auto” mode is a passive negotiation mode that sets the ports on the devices in a passive state.
“Desirable” is an active negotiation that allows for package delivery between different switches by setting the ports in an active state. The final mode is the “on” mode with no protocols.
The devices are set in the “Desirable” state by default. As only Cisco devices can operate using this protocol, only Cisco-licensed vendors can use this protocol. This limits the flexibility of this model, but the network traffic is greatly managed.
The only drawback of the Port Aggregation Protocol (PAgP) is that all the ports using the protocol must be on the same device. Ports of different devices are not aggregated into a group.
Main Differences Between Cisco LACP and PAgP
- Cisco LACP operates on Ethernetchannel as well as IEEE 802.3ad channel. PAgP only operates on Ethernetchannel.
- LACP was designed to support other network devices. Hence it is an open protocol. PAgP can only support ports of Cisco switches.
- IEEE 802.3ad authorized LACP in the year 2000. Cisco developed PAgP in the early 90s.
- LACP sets the ports in Active mode by default. PAgP sets the ports in Desirable mode by default.
- LACP ports can only respond to package requests. PAgP ports can respond to requests as well as send packages.