Packet loss on MX100

stgonzo
Getting noticed

Packet loss on MX100

 

We have an issue with packet loss on an MPLS connection, this is a network which moved to a new office where the parent company’s MPLS connection is used, the old office the ISP connection used a primary and secondary leased line, no issues.  On the new site, users have been complaining of slow files transfers and MS Teams calls breaking up (only seems to break up for the users in the office, the people on the other end have no issue).  Some days users have no issues with MS Teams calls.

 

We set up some monitoring to various devices on the network and see a daily pattern of packet drops during certain times each weekday, doesn’t fully tie up with the office starting and finishing times.  MX WAN usage never goes over the 40% of the maximum available, we have tried Uplink configuration at 500Mbps (ISP link speed) and 1 Gbps (max), also tried with AMP off.  Firmware is on 16.16

 

We have logged a couple of tickets with Meraki, they have had a look at various settings and run packet captures, they say that the MX100 doesn’t look like it is dropping packets and the issue is more likely to be on an upstream hop.  Reporting back to the ISP, they say they can’t see any issues and speeds are fine.  We have raised this with the parent company, and they are putting it down to double NAT, we suspect there is some sort of policy applied on our connection, but don’t seem to be getting anywhere with the Parent company or ISP about this, MPLS firewall is co-managed by both.

 

We are trying to get another ISP connection installed but this may be some time off, just looking for ideas to move forward with this

6 Replies 6
alemabrahao
Kind of a big deal
Kind of a big deal

How many clients do you have under MX?

I am not a Cisco Meraki employee. My suggestions are based on documentation of Meraki best practices and day-to-day experience.

Please, if this post was useful, leave your kudos and mark it as solved.

Some days it may be 10, some other days up to 60

alemabrahao
Kind of a big deal
Kind of a big deal

I see, I read some documentation, but I did not find any special configuration for MPLS.

 

https://documentation.meraki.com/MX/Site-to-site_VPN/Configuring_Site-to-site_VPN_over_MPLS

 

https://documentation.meraki.com/MX/Deployment_Guides/MPLS_Failover_to_Meraki_Auto_VPN

I am not a Cisco Meraki employee. My suggestions are based on documentation of Meraki best practices and day-to-day experience.

Please, if this post was useful, leave your kudos and mark it as solved.
cmr
Kind of a big deal
Kind of a big deal

@stgonzo If you monitor a device on the other end from the site with the MX100s does that show the packet loss?  You could try forcing the speed and duplex of the WAN port, perhaps the MPLS router has them manually set.  The other thing to check is MTU size, check what the MPLS is using.  Also the MX100 only supported 650Mbps of throughput, so I wouldn't set the limit any higher than that.

PhilipDAth
Kind of a big deal
Kind of a big deal

This smells like a speed/duplex mismatch.

 

Check what the ISP is using (auto/auto, 1000/full, etc) and make sure the MX WAN port is configured the same way.

Thanks, I checked this after seeing one of you previous posts/replies. On this one, both sides set to Auto/Auto.

 

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