© 2015 Mohamed Samir YouTube channel All rights reserved. Samir CCNP-SWITCHING 300-115 Mohamed Samir YouTube channel Double

© 2015 Mohamed Samir YouTube channel All rights reserved. www.mohamedsamir.comMohamed Samir

CCNP-SWITCHING 300-115Mohamed Samir YouTube channel

Double CCIEs #27042(R/S&SP)


Part III Working with Redundant Links


Aggregating Switch Links


SW1

SW4

FA0/2

SW3

SW2

FA0/1FA0/1

FA0/1

FA0/11

FA0/11FA0/1

FA0/2

FA0/2 FA0/2


Switch Port Aggregation with EtherChannel

Two to eight links can be aggregateFor redundancy Link expansion & grow the load is not always distributed equallyamong 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 ofthe 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-protocol pagp• 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-protocol lacp• 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• Switch(config-if)# channel-protocol lacp• Switch(config-if)# channel-group 1 mode active


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 ?


Thank you for your time !

شكراخير الله جزاكم

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© 2015 Mohamed Samir YouTube channel All rights reserved. Samir CCNP-SWITCHING 300-115 Mohamed Samir YouTube channel Double