Lacp Active Vs Passive – How to Configure PAgP and LACP!

EtherChannel can be used to bundle physical links right into a single logical link. We are able to bundle more 8 physical links into one logical link. When physical links bundled right into a single logical link, the STP only sees just one logical link and can’t block anything.

There’s two kinds of protocol employed for EtherChannel, Port Aggregation Protocol (PAgP) and Link Aggregation Control Protocol (LACP). EtheChannel protocols remove any loops inside the physical links.


The Etherchannel protocols also maintain an eye on each physical link. In situation associated with a physical link failure or restoration, the protocols manage the deletion and inclusion of the hyperlink without informing the STP concerning the change.  ‘cisco’ switch uses the IEEE standard Link Aggregation Control Protocol (LACP)  and ‘cisco’ proprietary Port Aggregation Protocol.

Each EtherChannel is known as a funnel group. We are able to give a physical port in to the group while using “channel-group group-number mode on” command within the interface configuration mode. We are able to also create and configure the EtherChannel without using PAgP or LACP. This kind of EtherChannel is known as a static or Unconditional EtherChannel.


Port Aggregation Protocol (PAgP)

Port Aggregation Protocol is really a ‘cisco’-proprietary protocol that may only focus on ‘cisco’ switches or on switches licensed by vendors to aid Port Aggregation Protocol. The protocol helps the automated development of Etherchannel while using exchange of PAGP packets.

Port Aggregation Protocol packets are exchanged between EtherChannel-capable ports to barter the establishment of the funnel. Port Aggregation Protocol also checks for configuration stability and manages link additions and failures between two switches. It helps to ensure that when an EtherChannel is produced, all ports have a similar kind of configuration.

PAGP packets contain all the details from the neighbour switch. The receiving switch learns the neighbour switch identity capacity of supporting PAGP after which dynamically groups similarly configured ports right into a single logical link.  When PAgP is enabled, the PAgP packets are sent after every thirty seconds. The Main Harbour-Aggregation Protocol (PAgP) uses the layer 2 multicast address 01-00-0C-CC-CC-CC.


For creating EtherChannel, all ports must have a similar data speed, duplex setting, and VLAN information. Any modification around the port configuration may cause changes on other ports from the funnel. The figure shows the modes for Port Aggregation Protocol.

  • On- Interfaces configured with this particular mode don’t exchange PAgP packets. On mode pressure the interface to funnel without PAgP or LACP. Port with “on” mode, is going to be produced EtherChannel only if another interface group in EtherChannel “on” mode.
  • PAgP desirable- Interface with PAgP desirable mode stay in an energetic negotiating condition where the interface initiates negotiations along with other interfaces by delivering PAgP packets after every thirty seconds.
  • PAgP auto- Interface with PAgP automatic mode places the interface inside a passive negotiating condition where the interface answer the PAgP packets received, but doesn’t initiate any Port Aggregation Protocolnegotiation.


For creating EtherChannel the modes compatibility on side is essential. For instance, if a person side is configured to stay in automatic mode, awaiting sleep issues to initiate the EtherChannel settlement

If sleep issues can also be set to auto, the PAgP packet won’t ever exchange and also the EtherChannel doesn’t form. If all modes are disabled, or maybe no mode is configured, then your EtherChannel is disabled. The figure below illustrates the mode from the Port Aggregation Protocol for EtherChannel establishment.

The on mode by hand set the interface within an EtherChannel, with no settlement. If a person side is placed to on the other hand should be set to for creating EtherChannel. If sleep issues is placed to barter parameters through Port Aggregation Protocol, the EtherChannel isn’t feasible, since the side that’s set to on mode doesn’t negotiate. The Etherchannel configuration for that above topology is really as under:


Note:- PAgP Modes are: On, Desirable, Auto



Switch1(config)#interface range e0/-3

Switch1(config-if-range)#funnel-group 1 mode auto

Switch1(config-if-range)#interface port-funnel 1

Switch1(config-if)#switchport mode trunk



Switch2(config)#interface range e0/-3

Switch2(config-if-range)#funnel-group 1 mode desirable

Switch2(config-if-range)#interface port-funnel 1

Switch2(config-if)#switchport mode trunk


The Main Harbour Aggregation Protocol will a configuration check up on participating interfaces and confirms the neighbouring interfaces will also be using Port Aggregation Protocol. Within the Port Aggregation Protocol interfaces that do not have similar configurations won’t participate, so we won’t have an accidental switching loop.



LACP is definitely an open protocol, printed by IEEE underneath the 802.3ad specs. The IEEE also to produce new meaning of the LACP in IEEE 802.1AX standard for local and metropolitan area systems. LACP, similarly enables several physical ports to become bundled to determine just one logical funnel.

It enables a change to negotiate a computerized bundle while using LACP packets. The part from the LACP is comparable to PAgP with ‘cisco’ EtherChannel. The main difference is the fact that LACP is definitely an IEEE standard and PAgP is ‘cisco’ Propiaritry. The LACP can be used to determine EtherChannels in multivendor environments. On ‘cisco’ devices, we are able to use both protocols. The LACP uses multicast address 01-80-c2-00-00-02.


LACP is identical within the functioning and demonstrated exactly the same settlement benefits as PAgP. It will help establish the EtherChannel link by discovering the configuration of every side and appearance the compatibility. The figure shows the various modes for LACP.

  • On- similarly the on mode make sure the interface to funnel without LACP. Interfaces with this particular mode don’t exchange LACP packets.
  • LACP active- The active mode places a port within an active negotiating condition. The main harbour starts negotiations along with other ports by delivering LACP packets.
  • LACP passive- The passive mode places a port inside a passive negotiating condition. Within the passive mode, the main harbour reacts to the LACP packets it receives, nevertheless the passive port doesn’t initiate LACP packet settlement.

Much like PAgP, modes should be compatible on sides for creating EtherChannel. The on mode is repeated since it produces the unconditional EtherChannel configuration without PAgP or LACP dynamic settlement. The straightforward configuration of LACP for that above topology is really as under:


Note:- LACP Modes are: On, Active, Passive



Switch1(config)#interface range e0/-1

Switch1(config-if-range)#funnel-group 1 mode active

Switch1(config-if-range)#interface port-funnel 1

Switch1(config-if)#switchport mode trunk



Switch2(config)#interface range e0/-1

Switch2(config-if-range)#funnel-group 1 mode passive

Switch2(config-if-range)#interface port-funnel 1

Switch2(config-if)#switchport mode trunk

The configuration of LACP is nearly same to PAgP configuration. The main difference is simply the utilisation of the keyword. The keywords utilized by LACP is active and passive. The active keyword implies that the interface uses LACP protocol. The passive keyword signifies using LACP, however, it may only react to demands but cannot send any LACP packet.

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