Hot Downloads

Welcome, Guest
Username: Password: Remember me

TOPIC: LACP on C3750 switches

LACP on C3750 switches 6 years 1 month ago #35660

  • simwintech
  • simwintech's Avatar
  • Offline
  • New Member
  • Posts: 10
  • Karma: 0
Hi,

2 x C3750 switches are interconnected with each other using 2 x fibre optic cables and i want to bind the bandwidths of two ports to 2Gbps using LACP on C3750 switches. Below are the configurations done on both the Cisco switches and LACP is not working, still getting 1 Gbps speed.

Switch A port Gig1/1 is connected with Switch B port Gig1/1
Switch A port Gig1/2 is connected with Switch B port Gig1/2

Switch A:

# Interface Gig1/1
channel-protocol LACP
channel-group 1 mode active

# Interface Gig1/2
channel-protocol LACP
channel-group 1 mode active

Switch B:

# Interface Gig1/1
channel-protocol LACP
channel-group 1 mode active

# Interface Gig1/2
channel-protocol LACP
channel-group 1 mode active

Can anyone help me?
The administrator has disabled public write access.

Re: LACP on C3750 switches 6 years 1 month ago #35662

  • S0lo
  • S0lo's Avatar
  • Offline
  • Moderator
  • Posts: 1577
  • Thank you received: 7
  • Karma: 3
Your config is probably OK. Etherchannel is not strictly round robin load-balancing. In otherwords, Etherchannel does NOT necessarily distribute the load evenly across the aggregated links to utilize the the sum of the bandwidths

As far as I know, Cisco's Etherchannel (in many switch models including the 3750) usually uses information in the frame (like the source/destination MAC address or source/destination IP address) to determine what physical port the frame will be sent through. This is why if your sending from a single host to a single host, it would probably end up using only one port on the switch (thus the 1Gbps).

Try sending from say host A to host B and from host C to host D at the same time. See if that makes a difference.

You can configure the load balancing and forwarding method using the port-channel load-balance command.

You can also find out which interface is used in the EtherChannel to forward traffic based on the load balancing method using test etherchannel load-balance interface port-channel command

Hope this gives a clue.
Studying CCNP...

Ammar Muqaddas
Forum Moderator
www.firewall.cx
The administrator has disabled public write access.

Re: LACP on C3750 switches 6 years 1 month ago #35663

  • Losh
  • Losh's Avatar
  • Offline
  • Distinguished Member
  • Posts: 103
  • Karma: 0
Just to be sure your etherchannel is up,type this command.

Switch#show etherchannel summary

the port channel should be up & with the initials (SU) if its L2.
Then again Solo is right,as usual.
~ Networking :- Just when u think its starting to make sense......... ~
____________________________________________
CCNA, CCNP, CCNA Security, JNCIA, APDS, CISA
The administrator has disabled public write access.
Time to create page: 0.077 seconds

CCENT/CCNA

Cisco Routers

  • SSL WebVPN
  • Securing Routers
  • Policy Based Routing
  • Router on-a-Stick

VPN Security

  • Understand DMVPN
  • GRE/IPSec Configuration
  • Site-to-Site IPSec VPN
  • IPSec Modes

Cisco Help

  • VPN Client Windows 8
  • VPN Client Windows 7
  • CCP Display Problem
  • Cisco Support App.

Windows 2012

  • New Features
  • Licensing
  • Hyper-V / VDI
  • Install Hyper-V

Linux

  • File Permissions
  • Webmin
  • Groups - Users
  • Samba Setup