Cradlepoint CBA850 and MX84

[dsekely_brs]

Need some assistance from the users that have successfully setup a cradle point as a cellular backup device for an MX84.

Here is what I am experiencing.  When connected to the cba850 directly from my laptop the cellular connection is smooth, speeds and signal strength are also good.  When I connect the cba850 to a WAN port on the MX84 and access the internet through the MX I get spotty connection.  Sometimes it is good and I can run speed tests and browse sites and other times sites time out as well as speed tests.   When I am able to run speed tests they line up with the speed I was seeing while directly connected to the cba850.  I had similar issues when using the USB modems connected to the MX84 but was never able to successfully browse websites so I am moving in the right direction.

We are using verizon without static IP and using the LAN2 port for IP Pass through.

Any help/suggestions would be appreciated.

[NolanHerring]

What firmware version is your MX84 running?
Do you have firewall features enabled like IPS/Malware/Content Filtering/VPN/SpeedThrottling etc.

I would whitelist your test client to make sure none of those things are causing you grief.

[dsekely_brs]

MX firmware is 14.40

We do have some of those features enabled but I was also able to mirror our production setup on a test MX84 and with just my laptop connected things were fine.  I seem to have the issues when I add more devices behind the MX84 if that makes sense.

[NolanHerring]

Well..hmm...what if you were to whitelist all clients (or just disable those features) and then test again with more clients behind it. If it still fails, I would suspect it might be a limitation of the wireless connection.

Using one client might work fine but when you start tossing in 10, 50, 100 people behind it, I could see it starting to tank. Just a theory at this point of course

[drgnslyr]

Have you checked your MTU? We've had problems with Verizon cradlepoints and cellular modems connected to our Meraki MX's and had to have support adjust the MTU setting down a bit to get a smooth connection.

[dsekely_brs]

I haven't looked on the Meraki side.  I have made sure the cradle point was using the specified 1428 MTU

[jdsilva]

I like @drgnslyr 's answer here. The MX defaults to the Ethernet default of 1500. If the cradlepoint is at 1428 then this could indeed be the problem. You cannot change the MTU of the MX in the dashboard, for that you have to call support and request them to make the change for you.

[dsekely_brs]

Having support change the MTU to 1428 which is what the cradlepoint is set to did not make any difference.

Any other suggestions or information that would assist in troubleshooting?

[NolanHerring]

Never messed with MTU stuff before. Would making it smaller do anything (on both devices), say like in the 1300-1400 range? (general question for anyone with experience out there on this).

[dsekely_brs]

I also tried turning off IDS and AMP and didn't see any change.  I don't expect this connection to be as fast and stable as cable/fiber but I was honestly expecting more than what I an experiencing.

[jdsilva]

Ugh. I'm not sure I have any other guesses here. Hopefully someone else can think of something. 

You could try and take the packet capture approach and see if you can see any problems that way. That's probably what I would try next. 

[cmr]

Can you try 15.16 on your test MX84 with a few more clients?  We use 15.14, 15.15 and 15.16 as our production firmwares but we only use the enterprise feature set.

[dsekely_brs]

@cmr I have not tried the 15.x firmware with the cradlepoint.  I did however try it when I was troubleshooting a USB modem prior to getting the cradlepoint.  The 15.x firmware did not help with the USB modem

[Happiman]

@dsekely_brs 

When you're configuring CradlePoint, and Meraki, which IP address do you use on Meraki WAN interface?

I had some issues using pass-through mode. I always purchase a staic IP address and set the cradlepoint as a dhcp server, then Meraki WAN interface is configred for "DHCP"

[dsekely_brs]

@Happiman The Meraki WAN interface is set for DHCP and I'm using the dynamic IP from verizon connected to the pass-through LAN2 port on the CradlePoint.

[Happiman]

@dsekely_brs 

I see. What I noticed when I dealing w/ 4G LTE device, its public IP address and default gateway share the same IP address. And I couldn't access the local portal page from other remote site.

Do you think you can change the IP setting to "NAT" and run the DHCP service from it ?

.

[dsekely_brs]

@Happiman Isn't that the same as using LAN1 instead of LAN2?  If so I tried that as well.

[Happiman]

with Skyus DS(Verizon), I get 3Mbit/s, and CradlePoint, 7-10Mbit.

What is your average and worse speed?

[dsekely_brs]

@Happiman  With the Cradlepoint I avg 15Mbps D and 8Mbps U

Did you see my response regarding setting the Cradlepoint as a DHCP server instead of Pass through to my Meraki MX?

[Happiman]

@dsekely_brs 

Yes I saw your response that you're still having the same issue.

Can you share the network performance data while you're running the speed test ?

[WldWzl]

I have had issues with Verizon LTE and MTU, in our environment we had to drop the MTU to 1350 to get stable performance, this was a change made on the MX side by support.  We ran into this with another vendor's LTE modem as well.

[dsekely_brs]

@WldWzl Did you experience similar issues as me before the MTU change? 

I tested this unit again on different network within our organization and the results were the same.  I was testing with two users trying to do speed tests and it was timing out and pages taking a while to load

[WldWzl]

@dsekely_brs  that is correct, your issue sounds almost identical to what we experienced before having the MX port MTU changed.

We found the issue first with our ISRs and were able to make adjustments until we found an MTU that Verizon would work with, happened to be 1350.