Exch 2016 to O365 migration dropping packets

[forkies]

Dear all,

 

We are having a strange issue where by when I start any mailbox migrations going to O365 from on prem O365 we are having substancial packet loss on internet feed.

 

We have a 1Gb/1Gb leased line. Smoothwall S8 appliance. Smoothwall is at Leeds 28. Router is ISP provided Juniper SRX300 managed by them.

 

When the migration of some mailboxes starts we notice a considerable drop in pings outbound/inbound. Generally pinging from our internal network to the smoothwall is not dropping packets but pinging from smoothwall to router is dropping packets. Carrier and ISP saying no issues but high level of traffic coming from our network. I even limited the exchange server to a 100Mbps port and same happened. Internally everything is testing fine but traffic in/out of the network is effectively dropping 10+% of packets.

 

Not really sure why this would be given that the traffic is 30-60Mbps so we have plenty of capacity and never had any issues like this before. Has anybody come across something like this before or have any ideas as to why this is happening?

 

It is not really a big issue as I can just set migrations to happen overnight but it would be helpful if I could get them running through the day as we are currently getting about 16 mailboxes done per night.

 

Thanks,

Tom