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Martin_Vlasko's avatar
Martin_Vlasko
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Nov 20, 2019

What are F5 VE SINGLE-NIC deployment limitations and considerations?

Hi,

I have a requirement from the client, that for a new F5 VE cluster I have to use only 1 single subnet for all interfaces.

Management, data and sync traffic - everything on the same subnet/vlan.

In standard multi-NIC mode, I would not be allowed to have IPs from the same subnet on both management and data interface.

So I had to fall back to single-NIC mode. But here I am struggling.

Some sources mention that HA is not available in single NIC mode, but I need HA.

I tried it anyway. I forced the VE to single-NIC mode:

tmsh load sys config default
tmsh save sys config
setdb provision.1nic forced_enable
reboot

After reboot, the web management GUI is now available on port 8443 as expected.

And I configured the interfaces:

VE1:

mgmt: 10.10.10.10

data: 10.10.10.20

sync: 10.10.10.30

VE2:

mgmt: 10.10.10.11

data: 10.10.10.21

sync: 10.10.10.31

Management IP/mask and management route 10.10.10.1 are configured through System->Platform.

I haven't configured any default gateway under Network->Routes, because doing so I would have 2 default routes for the same subnet.

Ping from VE1 to VE2 mgmt does NOT work

Ping from VE1 to VE2 data does work

same situation when testing from the other side.

I managed to form a cluster, but only with data interfaces, not management ones.

Then I experienced many unexpected failovers, no clue why they are happening.

Could somebody advise, what all is required to configure for single-NIC HA cluster?

And what are the limitations? is it even possible to achieve HA with single-NIC deployment?

Thanks.