Hello all !

I have a trouble between 2 router in cascade. The first, an LHGG (LTE6 in router mode), second an hEX.
This config (router+router) is due to isolate some clients on another network.

Problem, i have 150 mbits of bandwidth connected directly on my LHGG, 45/50 max on the hEX (CPU low, no other client connected, conf stock with only FW default rules).
If i try to contact, through the hEX a fileserver (on the LHGG network), i have the full bandwidth.

I have test to activate/deactivate the fastrack (on LHGG and on hEX), nothing change.

The problem is only with the web through the hex ---> LHGG.

Any idee ?

Start with the basics.
What is the connection speed on the port?

Yes, all ports are in gigabit, all links are ok.

U can find my config in attachment.

But i have make some other tests and the problem seems to be linked to the first router : the LHGG !
Because i have already an ubiquiti er-X in place (who i want to replace), and this router have .... the same limitation (average 35---55 mbits/s) when i go to the WEB !

I have:
- Limited to the strict minimum all FW rules, no mangles, no NAT rules
- check the CPU when i try the speedtest : CPU of LHGG : 15-20% maximum
- all ROS are up to date and the LTE firmware modem is up to date

What's happened ? What's the best pratictice when i cascade 2 routers ?
MTU ?

Problem solved !

Issue due to an Ubiquiti WLAN out of date. I have, between my MT hEX and my LHGG an old WLAN ubiquity with a POE output (to link the LHGG), to simplify my installation....

Ubiquity replaced by a simple AC LR, direct connection between my hEX and my LHGG : full bandwith !

This config (router+router) is due to isolate some clients on another network.

Unless you've got multiple subnets (thus actual routing rules between them) I wouldn't describe this as router+router. It's a router and a smart switch. The hEX line makes a great upgrade to the CSS106 when a classic switch design doesn't have all the brains you want.

45/50 max on the hEX…hEX a fileserver (on the LHGG network), i have the full bandwidth.

I'm replying after you said you fixed this, but I remain confused about this pair of claims. If I'm right about what an "AC LR" is (this?) are you saying you now have a wireless link between the hEX and the LHGG?

You say the LHGG is PoE-powered. Are you replacing that wired link with wireless? If so, then maybe the problem was that your "gigabit" link dropped to 100 Mbit/sec due to PoE negotiation problems. Getting gigabit with PoE isn't always plug-and-play.

I'm a big fan of wired backbones, even in home settings with a lot of wireless going on. Maybe what you need is to upgrade from passive PoE to 802.3af/at.

Don't guess or take my speculations as gospel. The PoE readouts under RouterOS will indicate if this is what's happening.

ubiquiti er-X in place (who i want to replace)

The hEX is a pretty good match, feature-wise, but I prefer either the hEX PoE when I need PoE and the hEX S otherwise, because they have the SFP port for connecting by fiber back to a core switch. It's too bad that LHGG doesn't have SFP, but since you say you're PoE-powering it, both upgrades to the base hEX model (RB750Gr3) do better with PoE.

Whether this fixes your speed bottleneck is another question. I can't speak to that, since I don't have an LHGG.

What's the best pratictice when i cascade 2 routers ?

First commandment: don't do double-NAT.

This is part of the distinction I'm trying to make about routers vs smart switches. These hEX boxes are often considered home Internet gateway routers, but you wouldn't configure them like that in a setup like yours. They're better used as:

1. smart switches, extending the same flat LAN your gateway router sits on; or
2. subnet routers, extending a flat LAN with region boundaries (e.g. home office vs bedrooms); or
3. VLAN routers, extending #2 when you have ports that have to be on 2+ subnets at the same time

Nowhere in here do you use the hEX as a NAT router, only ever as a subnet router. Other than that, your choice of modes is up to you, matching needs to desired limits on complexity.