I just received my z100g and I must admit, I'm thoroughly impressed so far. I've only encountered one issue - I have avast antivirus installed on my laptops and it seems as if it's having trouble reaching its destinations to upgrade its virus database. From the z100g's logs, it appears that avast is sending "null payloads" to various IP addresses, all of which seem to be legitimate avast servers. Has anyone else encountered this? Is there a suggested workaround or solution? I'd rather not allow all null payloads, but it's hard to build a rule with so many seemingly random IP addresses. Thanks.

Can you please use a sniffer to capture the avast traffic and see if it is indeed null payload traffic?
If it is, then there's nothing we can do about it - it is blocked because this is what this feature does. If not, then it may be a bug and we need to investigate it further.
Please email the sniffer capture to our support team.
Thanks,
Oren

I solved the problem by turning off Avast's automatic network detection, which was sending out pings looking for a proxy server.