CCNP-SWITCHING 300-115 Mohamed Samir YouTube channel Double CCIEs #27042(R/S&SP)

Part III Working with Redundant Links

Aggregating Switch Links

SW2 SW1 FA0/1 FA0/1 FA0/11 FA0/2 FA0/2 FA0/11 FA0/1 FA0/1 FA0/2 FA0/2 SW4 SW3

Switch Port Aggregation with EtherChannel Two to eight links can be aggregate For redundancy Link expansion & grow the load is not always distributed equally among the individual links EtherChannel also provides redundancy with several bundled physical links

Switch Port Aggregation with EtherChannel cont. distributing the physical links across multiple switches at each end of the EtherChannel. Cisco stackable Catalyst switches or chassis-based Virtual Switching System (VSS) switch families. This known as This is known as a multichassis EtherChannel (MEC).

Bundling Ports with EtherChannel From 2 to 8 with the same type carry the same set of vlan and same native vlan Distributing Traffic in EtherChannel The algorithm can use source IP address, destination IP address, or a combination of source and destination IP addresses, source and destination MAC addresses, or TCP/UDP port numbers

Configuring EtherChannel Load Balancing Switch(config)# port-channel load-balance method

Configuring EtherChannel Load Balancing cont. In common access layer switch (3750) the default is src-mac You can verify the load balancing method currently Switch# show etherchannel load-balance If one source , multiple source , router source,non IP source ,….etc To verify that you use the right one show etherchannel port-channel

EtherChannel Negotiation Protocols The Port Aggregation Protocol (PAgP) is a Cisco proprietary solution Link Aggregation Control Protocol (LACP) is standards based.

Port Aggregation Protocol PAgP also dynamically modifies parameters of the EtherChannel PAgP can be configured in active mode (desirable), or in passive mode (auto, the default), Link Aggregation Control Protocol The switch with the lowest system priority is allowed to make decisions about what ports actively are participating in the EtherChannel at a given time LACP, a switch selects up to eight of these having the lowest port priorities as active Ether Channel links at any given time. The other links are placed in a standby state

EtherChannel Configuration Configuring a PAgP EtherChannel Switch(config)# interface type member/module/number Switch(config-if)# channel-protocol pagp Switch(config-if)# channel-group number mode {on | {{auto | desirable} [non-silent]} Silent for connection with server Switch(config)# port-channel load-balance src-dst-port Switch(config)# interface range gig 1/0/1 – 4 Switch(config-if)# channel-group 1 mode desirable non-silent

Configuring a LACP EtherChannel Switch(config)# lacp system-priority priority priority defined (1 to 65,535)(if equal poriority lowest mac-add Switch(config)# interface type member/module/number Switch(config-if)# channel-protocol lacp Switch(config-if)# channel-group number mode {on | passive | active} Switch(config-if)# lacp port-priority priority Example Switch(config)# lacp system-priority 100 Switch(config)# interface range gig 1/0/1 – 4 , gig 2/0/1 – 4 Switch(config-if)# channel-group 1 mode active Switch(config-if)# lacp port-priority 100 Switch(config-if)# exit Switch(config)# interface range gig 1/0/5 – 8 , gig 2/0/5 – 8

Avoiding Misconfiguration with EtherChannel Guard STP will not operate consistently on all interfaces because Switch A is expecting a working EtherChannel. The solution:EtherChannel Guard Switch(config)# [no] spanning-tree etherchannel guard misconfig To recover from a misconfigured EtherChannel Switch(config)# interface port-channel1 Switch(config-if)# shutdown Switch(config-if)# no shutdown

Troubleshooting an EtherChannel

Troubleshooting an EtherChannel Switch# show etherchannel summary Switch# show etherchannel port Show etherchannel load-balance

Any questions ?

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