I have a GTM with a single ethernet connection to a switch. My goal is to establish a second ethernet connection to a second switch for redundancy. But my understanding from our Cisco guys is that I can't etherchannel across two different switches. From the F5 perspective, it appears that I can simply add a second physical interface to the VLAN. Will that work if I have two interfaces, which are not trunked, in a single F5 VLAN, connected to two different switches?

It depends on what type of Cisco switches. Some switches can be "stacked" that is two or more individual switches appear as a single switch.

Ask your Cisco guys if they can do LACP Etherchannels and rejoin them in the back end. I know some of the Nexus switches do this, because I've done it. It's a trunk on the F5 side, but don't tell them that, a Trunk is tagged VLANs in the Cisco world.

Thanks for your comments. I am aware, generallly speaking, of virtual etherchannel capability on the Nexus platform, but that isn't an option here - I am connected to 3500-series switches. We are doing (Cisco) LACP etherchannels on some of our F5 equipment already, so we do understand the difference between F5 and Cisco terminology (though that took some time to work through). I don't have any experience managing networking equipment outside F5 - intuitively it seems like it would be problematic if two different switches both see the same MAC address of the F5 VLAN?

I cant think of any cisco switches hat do not do lacp... Catos perhaps, but thats been obsolete for a long time. Nexus ONLY does LACP. No pagp at all. Smp... If you want to etherchannel over more than one switch you either need nexus (vPC), VSS on a 6500 (single control plane acorss multiple switches), or a 3750 switch stack (which looks like a singke switch having Multiple modules) H

I'm probably not communicating this very well. My goal is still to get some network redundancy *without* etherchannel. My idea is to simply connect two F5 interfaces to different switches, then add both F5 interfaces into the F5 VLAN. I'm wondering if this config will work without an F5 trunk, since I can't do etherchannel.

assigning multiple interfaces to VLAN

giltjr
Nimbostratus
Jun 28, 2012
It depends on what type of Cisco switches. Some switches can be "stacked" that is two or more individual switches appear as a single switch.
El_Jefe
Nimbostratus
Jun 28, 2012
Ask your Cisco guys if they can do LACP Etherchannels and rejoin them in the back end. I know some of the Nexus switches do this, because I've done it. It's a trunk on the F5 side, but don't tell them that, a Trunk is tagged VLANs in the Cisco world.
smp_86112
Cirrostratus
Jun 28, 2012
Thanks for your comments.

I am aware, generallly speaking, of virtual etherchannel capability on the Nexus platform, but that isn't an option here - I am connected to 3500-series switches. We are doing (Cisco) LACP etherchannels on some of our F5 equipment already, so we do understand the difference between F5 and Cisco terminology (though that took some time to work through).

I don't have any experience managing networking equipment outside F5 - intuitively it seems like it would be problematic if two different switches both see the same MAC address of the F5 VLAN?
Hamish
Cirrocumulus
Jun 28, 2012
I cant think of any cisco switches hat do not do lacp... Catos perhaps, but thats been obsolete for a long time. Nexus ONLY does LACP. No pagp at all.

Smp... If you want to etherchannel over more than one switch you either need nexus (vPC), VSS on a 6500 (single control plane acorss multiple switches), or a 3750 switch stack (which looks like a singke switch having Multiple modules)

H
smp_86112
Cirrostratus
Jun 28, 2012
I'm probably not communicating this very well. My goal is still to get some network redundancy *without* etherchannel. My idea is to simply connect two F5 interfaces to different switches, then add both F5 interfaces into the F5 VLAN. I'm wondering if this config will work without an F5 trunk, since I can't do etherchannel.
El_Jefe
Nimbostratus
Jun 28, 2012
@ Hamish - exactly what I was talking about.

@ smp - You can add VLANs to multiple interfaces. This might be helpful to read - http://support.f5.com/kb/en-us/products/big-ip_ltm/manuals/product/tmos_management_guide_10_1/tmos_vlans.html

Then, yes, as long as the ports on the different switches are on those VLANs, it would work. The MAC is different for each interface on the LTM, unless you are doing MAC Masquerading, then only the active box has that one. Regardless, it should work.
nitass
Employee
Jun 29, 2012
i think it is fine. also, if there is network connectivity between 2 switches, switch will block one link either between switch or bigip/switch by stp.
Hamish
Cirrocumulus
Jun 29, 2012
Just make sure you either have STP enabled either active or pass-though. If you block STP you'll get a bridging loop. That's bad... Symptoms ranging from it's a bit slow to 'oh my god the whole network just went down in both data centres'.

H
Hamish
Cirrocumulus
Jun 29, 2012
Just make sure you either have STP enabled either active or pass-though. If you block STP you'll get a bridging loop. That's bad... Symptoms ranging from it's a bit slow to 'oh my god the whole network just went down in both data centres'.

H
smp_86112
Cirrostratus
Jul 01, 2012
Is there a way to configure interfaces to work in an active/standby mode, so I can two interfaces connected to different switches, but only one being active?