Slow Site-to-Site VPN traffic

[DSklar]

I have a main office with an MX85 and a small remote office with a Z3. Recently, traffic through the VPN tunnel gets very slow during the day. After resetting the Z3, traffic will speed up for a couple of hours but then slow down again. Direct traffic to the internet is very fast at both ends. Pings through the tunnel start in the range 20-30ms but after a couple of hours suddenly increase to 500+ms. Pings to the outside IP address are in the <10ms range at all times. The Z3 reports bandwidth usage  under 5mb/s at peak, usually well below that. If I reset it after office hours, it returns to 20-30ms and stays that way until late morning the next day.

[RaphaelL]

Hi ,

Have you recently upgraded your MX/Z ? Let's say to version MX18.107 ?

[DSklar]

Yes, the Z3 is running firmware 18.107 and the MX85 is running 17.10.2

[RaphaelL · Accepted solution]

Lots of people claming that S2S performance dropped with that version : https://community.meraki.com/t5/Security-SD-WAN/New-MX-18-107-stable-release-candidate-firmware-many...

I personnally haven't noticed yet. ( running MX68 and MX450 )

[DSklar]

Thanks for point that out. I'll try switching to the stable release and see how it performs.

[DSklar]

A full day on the 17.10.2 firmware and the issue hasn't come back. I'm going to mark this as solved.

Thanks.

[cmr]

18.107.2 has been released to fix this bug 🙂

[ANC]

I have a StS configuration with 2 mx and 18.107.2 and the connection is 1Mb/s. The connection between one of them and a USG 3p with StS is 10Mb/s which is the maximum that the USG gives.