In this tutorial we will learn about PAGP.We will learn how to configure PAGP and how to verify and troubleshoot it after configuration. But before that we must know what PAGP is.PAgP is actually a Cisco Proprietary Protocol which is known as Port Aggregation Protocol which is used to combine two or more physical ports in to a single logical port or you can say it as a EtherChannel. PAGP is developed by CISCO company.The port modes are defined as either auto or desirable.
As we all Know there are total 3 Methods to Configure EtherChannel in cisco switch.
1.STATIC ( Configure it Manually or use below both protocols)
2.PAgP(Port Aggregation Protocol)
3.LACP(Link Aggregation Control Protocol)
Here in this tutorial we will learn to configure Etherchannel using PAgP .
NOTE:in real production environment we can either use PAGP or LACP.
Now going to configure PAgP EtherChannel in cisco switch:
STEP 1: PAGP Configuration on SWITCH 0
SWITCHA(config)#host switchA switchA(config)#int range fa0/1-2 switchA(config-if-range)#channel-group 1 mode desirable
STEP 2: Now go to Switch B and Configure PAgP
Switch(config)#host switchB switchB(config)#int range fa0/1-2 switchB(config-if-range)#channel-group 1 mode desirable
STEP 3: Verify EtherChannel PORT Configuration
switchA#show etherchannel summary Flags: D - down P - in port-channel I - stand-alone s - suspended H - Hot-standby (LACP only) R - Layer3 S - Layer2 U - in use f - failed to allocate aggregator u - unsuitable for bundling w - waiting to be aggregated d - default port Number of channel-groups in use: 1 Number of aggregators: 1 Group Port-channel Protocol Ports ------+-------------+-----------+---------------------------------------------- 1 Po1(SU) PAgP Fa0/1(P) Fa0/2(P)
switchA#show etherchannel load-balance EtherChannel Load-Balancing Operational State (src-mac): Non-IP: Source MAC address IPv4: Source MAC address IPv6: Source MAC address switchA#