Ok, I decided to step backwards, and start from the beginning. My first goal will be to make sure the hardware is ok, mainly, the network interfaces. I reinstalled Debian 10, turned it into a barebones router, and ran the *speedtest-netperf.sh* script from Openwrt , either from within the router, as well as from my 100/10 notebook. The results seem to indicate everything is fine: - From the server, the test maxes out the Internet link; - Fromt the notebook, the test kinda maxes out its interface roof: close to 90 Mbps in all four tests (I will assume this is because of poor hardware quality) I also switched WAN and LAN interfaces, just in case, and repeated the test, which gave similar results as before. PARTIAL CONCLUSION: So far so good. Attached, both results. *Atenciosamente,* *Gustavo Lapido Loureiro* Em qui., 4 de mar. de 2021 às 17:44, Gustavo Lapido Loureiro < gustavo.lapido@gmail.com> escreveu: > Hello, new member here. > First, thank you all involved in making this great piece of software, > which I have already experienced without issues during a couple of months. > Back then, it was on Openwrt, in a TP-LINK Archer C-7 router, bandwidth > capped to 60 Mbps (on the device's limits, but still making Internet usage > much smoother to all users). > Then I moved the router to a debian 10 Celeron J1900 mini-ITX, 4 GB of > RAM, two entry level Gigabit cards. > So far I couldn't get the stable A's in dslreports test I was getting with > the previous setup. > The point is that my Internet has been upgraded from 60 Mbps to 240/20 > Mbps. SInce most, if not all, devices are still 100 Mbps, I'm currently > capping cake at 85/18. > I basically "transported" the cake settings from Openwrt to debian, > basically adjusting the speed limits. > I would like to know where I start troubleshooting this, to help identify > what is causing bufferbloat on this new setup. > > Follow cake settings, then tc, then network hardware info > > *CAKE* > > # Uplink and Downlink values are in kbps > UPLINK=17500 > #DOWNLINK=216000 > DOWNLINK=90000 > > # SQM recipe to use. For more information, see /usr/lib/sqm/*.help > SCRIPT=piece_of_cake.qos > > # Optional/advanced config > > ENABLED=1 > QDISC=cake > > #LLAM=tc_stab > LINKLAYER=ethernet > OVERHEAD=22 > #STAB_MTU=2047 > #STAB_TSIZE=512 > #STAB_MPU=0 > > #ILIMIT= > #ELIMIT= > #ITARGET= > #ETARGET= > > # ECN ingress resp. egress. Values are ECN or NOECN. > IECN=ECN > EECN=NOECN > > # Extra qdisc options ingress resp. egress > IQDISC_OPTS="nat dual-dsthost" > EQDISC_OPTS="nat dual-srchost ack-filter" > > # CoDel target > #TARGET=5ms > > #ZERO_DSCP_INGRESS=1 > #IGNORE_DSCP_INGRESS=1 > > *TC SETTINGS:* > > qdisc noqueue 0: dev lo root refcnt 2 > qdisc pfifo_fast 0: dev enp2s0 root refcnt 2 bands 3 priomap 1 2 2 2 1 2 > 0 0 1 1 1 1 1 1 1 1 > qdisc cake 801b: dev enp3s0 root refcnt 2 bandwidth 17500Kbit besteffort > dual-srchost nat nowash ack-filter split-gso rtt 100.0ms noatm overhead 22 > qdisc ingress ffff: dev enp3s0 parent ffff:fff1 ---------------- > qdisc cake 801c: dev ifb4enp3s0 root refcnt 2 bandwidth 90Mbit besteffort > dual-dsthost nat wash no-ack-filter split-gso rtt 100.0ms noatm overhead 22 > > *NETWORK HARDWARE:* > > SCSI > *-network > description: Ethernet interface > product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller > vendor: Realtek Semiconductor Co., Ltd. > physical id: 0 > bus info: pci@0000:02:00.0 > logical name: enp2s0 > version: 06 > serial: c4:e9:84:00:1d:7b > size: 1Gbit/s > capacity: 1Gbit/s > width: 64 bits > clock: 33MHz > capabilities: pm msi pciexpress msix vpd bus_master cap_list > ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd > autonegotiation > configuration: autonegotiation=on broadcast=yes driver=r8169 > duplex=full firmware=rtl_nic/rtl8168e-2.fw ip=192.168.1.1 latency=0 > link=yes multicast=yes port=MII speed=1Gbit/s > resources: irq:17 ioport:e000(size=256) memory:d0704000-d0704fff > memory:d0700000-d0703fff > *-network > description: Ethernet interface > product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller > vendor: Realtek Semiconductor Co., Ltd. > physical id: 0 > bus info: pci@0000:03:00.0 > logical name: enp3s0 > version: 0c > serial: 44:8a:5b:94:96:37 > size: 1Gbit/s > capacity: 1Gbit/s > width: 64 bits > clock: 33MHz > capabilities: pm msi pciexpress msix vpd bus_master cap_list > ethernet physical tp aui bnc mii fibre 10bt 10bt-fd 100bt 100bt-fd > 1000bt-fd autonegotiation > configuration: autonegotiation=on broadcast=yes driver=r8169 > duplex=full firmware=rtl8168g-2_0.0.1 02/06/13 ip=179.210.1.62 latency=0 > link=yes multicast=yes port=MII speed=1Gbit/s > resources: irq:18 ioport:d000(size=256) memory:d0604000-d0604fff > memory:d0600000-d0603fff > *-network:0 > description: Ethernet interface > physical id: 1 > logical name: ifb4enp3s0 > serial: 76:6b:66:3c:6d:e9 > capabilities: ethernet physical > configuration: broadcast=yes > *-network:1 DISABLED > description: Ethernet interface > physical id: 2 > logical name: ifb1 > serial: 02:9e:3d:12:6e:16 > capabilities: ethernet physical > configuration: broadcast=yes > *-network:2 DISABLED > description: Ethernet interface > physical id: 3 > logical name: ifb0 > serial: 32:fe:93:2e:3a:1d > capabilities: ethernet physical > configuration: broadcast=yes >