06-11-2008 04:40 AM - edited 03-05-2019 11:33 PM
I believe that on UNIX operating system there is a way to configure multiple NICs with the same mac address and so realise a load balancing btw multiple interfaces. Is this something what would work in a cisco LAN infrastructure? Like two 3560s uplinked together, and both switches have one NIC with the same mac-address? (same VLAN)
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06-11-2008 06:22 AM
Your talking about NIC bonding. You cannot have the same mac-address tied to 2 NICs at once because you will create MAC Flapping on the switches. The only way to do this is to create an LACP bond with your NIC interfaces & the switch interfaces, but these have to be either stacked switches(3750G only) or 2 x 6500 in VSS configuration.
In your case with 2 3560's, you cannot run LACP to 2 different switches, you can however run LACP to a single switch and have 2-8 NICs connecting into this 1 switch, the LACP port-channel will see 1 mac-address that is basically shared between multiple NICs on the server.
NIC Bond Modes
Mode 0 - balance-rr
Single switch/stack configuration or multiple switch,create non-lacp etherchannels on switch
This also creates a lot of âout of orderâ packets and forces TCP congestion control to kick in because it balances a tcp stream.
Mode 1 - active-backup
Can use on multiple switches - best for High availability
Mode 2 - balance-xor
Single switch/stack configuration, create non-lacp etherchannels on switch
Mode 3 - broadcast
Multiple switch configuration or stack that is not trunked together and connects to outside networks
Mode 4 - LACP
Single switch/stack configuration , create lacp etherchannels on switch
Mode 5 - balance-tlb (transmit load balancing)
Can use on multiple switches
Mode 6 - balance alb (adaptive load balancing, both tx and rx)
Can use on multiple switches
If you plan on connecting into 2 different 3560 switches then you can use Mode 0,1,5,6
Note: Using mode 6, the âupdelayâ needs to be set to something equal or greater than the switches forwarding-delay, the cisco default forwarding delay is set to 15. Cisco value of 15 is determined based upon the STP Diameter traversing 7 switches to a layer 2 destination. If you change the spanning-tree diameter then you should change the âupdelayâ to this forwarding-delay.
Also, you cannot have "portfast" enabled on your bonded switch interfaces, portfast can be enabled with LACP, but you cannot use this in your config.
Hope this helps.
06-11-2008 06:22 AM
Your talking about NIC bonding. You cannot have the same mac-address tied to 2 NICs at once because you will create MAC Flapping on the switches. The only way to do this is to create an LACP bond with your NIC interfaces & the switch interfaces, but these have to be either stacked switches(3750G only) or 2 x 6500 in VSS configuration.
In your case with 2 3560's, you cannot run LACP to 2 different switches, you can however run LACP to a single switch and have 2-8 NICs connecting into this 1 switch, the LACP port-channel will see 1 mac-address that is basically shared between multiple NICs on the server.
NIC Bond Modes
Mode 0 - balance-rr
Single switch/stack configuration or multiple switch,create non-lacp etherchannels on switch
This also creates a lot of âout of orderâ packets and forces TCP congestion control to kick in because it balances a tcp stream.
Mode 1 - active-backup
Can use on multiple switches - best for High availability
Mode 2 - balance-xor
Single switch/stack configuration, create non-lacp etherchannels on switch
Mode 3 - broadcast
Multiple switch configuration or stack that is not trunked together and connects to outside networks
Mode 4 - LACP
Single switch/stack configuration , create lacp etherchannels on switch
Mode 5 - balance-tlb (transmit load balancing)
Can use on multiple switches
Mode 6 - balance alb (adaptive load balancing, both tx and rx)
Can use on multiple switches
If you plan on connecting into 2 different 3560 switches then you can use Mode 0,1,5,6
Note: Using mode 6, the âupdelayâ needs to be set to something equal or greater than the switches forwarding-delay, the cisco default forwarding delay is set to 15. Cisco value of 15 is determined based upon the STP Diameter traversing 7 switches to a layer 2 destination. If you change the spanning-tree diameter then you should change the âupdelayâ to this forwarding-delay.
Also, you cannot have "portfast" enabled on your bonded switch interfaces, portfast can be enabled with LACP, but you cannot use this in your config.
Hope this helps.
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