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

2. Part III Working with Redundant Links

3. Aggregating Switch Links

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

5. 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

6. 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).

7. 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

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

9. 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

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

11. 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

12. 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

13. 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

14. 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

15. Troubleshooting an EtherChannel

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

17. Any questions ?

18. Thank you for your time ! 
شكرا
جزاكم الله خير