Connecting Multiple 3560s

[slt81]

Can I use (2) SFP Patch Cables to link 2 Catalyst 3560s together instead of one? I am hoping it will increase the bandwidth between the 2 switches. Are there any special configuation settings that need to be taken into account?

Thanks
Scott

 

[NettableWalker]

Hi Scott,

Sounds like Etherchannel is what you are looking for.

Configure the ports as follows and they will load balance as if a much larger BW link.

interface Port-channel1
switchport trunk encapsulation dot1q
switchport trunk native vlan 99
switchport mode trunk
switchport nonegotiate

interface GigabitEthernet0/27
switchport trunk encapsulation dot1q
switchport trunk native vlan 99
switchport mode trunk
switchport nonegotiate
channel-group 1 mode desirable
!
interface GigabitEthernet0/28
switchport trunk encapsulation dot1q
switchport trunk native vlan 99
switchport mode trunk
switchport nonegotiate
channel-group 1 mode desirable


HTH.

MCP,CCA, Net+, Half CCNP...

 

[ADB100]

You can create an EtherChannel using upto 8 connections. All interfaces must be of the same speed and duplex - so on a 3560 you could combine the 4 SFP ports to create a 4Gbps channel. On a 3560G you could connect 8 1000BaseT ports and create an 8Gbps channel...

Do you need this much bandwidth?

interface GigabitEthernet0/1
channel-group 1 mode on
!
interface GigabitEthernet0/2
channel-group 1 mode on
!


The configuration of each port must be identical - i.e. if one is an 802.1q trunk allowinging VLAN's 10 & 20 then the others must be configured exactly the same. If you initally configure the ports as I have detailed above then configuring the logical PortChannel interface will replicate the configurations onto the physical members of the EtherChannel:

interface PortChannel 1
switchport trunk encapsulation dot1q
switchport mode trunk
switchport trunk allowed vlan 10,20
switchport trunk native vlan 900
!

This would be pushed to the physical EtherChannel members.

HTH

Andy

 

[slt81]

Given that there are (4) SFP ports per switch ... could I also use the other 2 fiber ports on each switch to connect back to my core?? (4 total connections back to the core ... 2 from each switch .. as well as the 2 SFP interconnect cables) I am assuming it will work and those additional ports will load balance back to my core stack which is a group of 3750s.

Thanks again,
Scott

 

[NettableWalker]

yes, that would work.

MCP,CCA, Net+, Half CCNP...