Here’s a problem that a couple of customers have run into recently.  Not an easy one to identify the cause of, so I wanted to post the solution/workaround here.

The Issue

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When you are trying to configure Network Connector Server on either IAG or UAG, you may encounter the following error:

‘Wrong Network Connector parameters, invalid segment address’

This error occurs no matter what configuration you apply to the Network Connector server

The Cause

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IAG & UAG both make an assumption that the first byte of your network card’s MAC address will be ‘00’.  Years ago this was a pretty safe bet, but this is not true anymore.  We are starting to see more Network cards with Organizationally Unique Identifiers (OUIs) – the first 24 bits of the MAC address – that do not have ‘00’ as the first byte.  If your network card falls into this category then you will encounter this problem.

So if your MAC address is 00-12-34-56-78-90 then Network Connector will work fine.  But if it is XY-12-34-56-78-90 (where either X or Y are not zero) then it will fail.

Note that only the MAC address of your INTERNAL interface matters here.  Network Connector does not perform any checks on your external interface.

The Solution

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There is a very easy workaround that can be applied in most cases.  Simply change the first byte of your internal NIC MAC address to ‘00’.  Most NIC drivers will let you do this, and whilst it’s not ideal, it will let you get Network Connector up and running. The UAG dev team are investigating the options for a proper fix in the longer term.  If you run into problems in the meantime (if your NIC driver doesn’t let you modify the MAC address for example) send me a message via this blog and I’ll try and help out.