Slow Steam download speed after switching from vdsl to ftth

glassyglass · Yesterday 09:13:20

Hello all,

I've recently switched from a vdsl connection to a 1gbp/s ftth. I have a router running openWRT connected through an ethernet cable straight to my ISP's provided ONT. Other than that, i am running adguard on another host on 192.168.1.116.

My issue is that Steam download speed are ridiculously slow, even slower than my speeds on my 100mbps vdsl connection. First thing I tried after reading online was messing with steam, switching download regions and deleting download cache. Also:

$ cat ~/.local/share/Steam/steam_dev.cfg 
@nClientDownloadEnableHTTP2PlatformLinux 0
@cMaxInitialDownloadSources 15

This did nothing.
At this point, i tried messing with my dns, even setting 1.1.1.1 as my default dns both locally and on my adguard. Also nothing

$ dig @192.168.1.116 store.steampowered.com

; <<>> DiG 9.20.24 <<>> @192.168.1.116 store.steampowered.com
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 21417
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;store.steampowered.com.		IN	A

;; ANSWER SECTION:
store.steampowered.com.	6	IN	A	2.16.189.131

;; Query time: 12 msec
;; SERVER: 192.168.1.116#53(192.168.1.116) (UDP)
;; WHEN: Sun Jun 21 12:05:36 EEST 2026
;; MSG SIZE  rcvd: 67

$ dig @1.1.1.1 steampowered.com

; <<>> DiG 9.20.24 <<>> @1.1.1.1 steampowered.com
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 20746
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;steampowered.com.		IN	A

;; ANSWER SECTION:
steampowered.com.	20	IN	A	23.196.141.21

;; Query time: 10 msec
;; SERVER: 1.1.1.1#53(1.1.1.1) (UDP)
;; WHEN: Sun Jun 21 12:05:59 EEST 2026
;; MSG SIZE  rcvd: 61

Next I've installed dnsmasq and set

 listen-addres=127.0.0.1

in /etc/dnsmasq.conf. Also probably related at this point

$ find /etc/systemd -type l -exec test -f {} \; -print | awk -F'/' '{ printf ("%-40s | %s\n", $(NF-0), $(NF-1)) }' | sort -f
autovt@.service                          | system
bluetooth.service                        | bluetooth.target.wants
cpupower.service                         | multi-user.target.wants
dbus-org.bluez.service                   | system
dbus-org.freedesktop.nm-dispatcher.service | system
dbus-org.freedesktop.timesync1.service   | system
display-manager.service                  | system
dnsmasq.service                          | multi-user.target.wants
docker.service                           | multi-user.target.wants
getty@tty1.service                       | getty.target.wants
gnome-keyring-daemon.socket              | sockets.target.wants
iwd.service                              | multi-user.target.wants
NetworkManager.service                   | multi-user.target.wants
NetworkManager-wait-online.service       | network-online.target.wants
p11-kit-server.socket                    | sockets.target.wants
paccache.timer                           | timers.target.wants
pipewire-pulse.socket                    | sockets.target.wants
pipewire-session-manager.service         | user
pipewire.socket                          | sockets.target.wants
reflector.timer                          | timers.target.wants
remote-fs.target                         | multi-user.target.wants
speech-dispatcher.socket                 | sockets.target.wants
sshd.service                             | multi-user.target.wants
systemd-timesyncd.service                | sysinit.target.wants
systemd-userdbd.socket                   | sockets.target.wants
wireplumber.service                      | pipewire.service.wants
xdg-user-dirs.service                    | graphical-session-pre.target.wants

Both speedtest.net and fast.com report speed >900mbps (even though they take a few seconds to ramp up, especially on fast.com) so i don't think i am isp throttled.

Finally, i tried passing everything through my vpn (using wireguard) but not much changed. Download speeds on steam maybe stabilized a bit more around 30mbps, but still far from the expected 90-100 i'd expect to see (and also fluctuating).
Also, on another machine on the same network I have a qbittorrent client which caps at around 90-100mbps.

Sorry for the long post but I am at a bit of a loss and out of ideas at this point. Cheers

Lone_Wolf · Yesterday 13:35:42

Both speedtest.net and fast.com report

What latency did they report and are download and upload same speed ?

Please post the outputs of

$ ip a
$ ip route
$ ip -6 route

from the router.

glassyglass · Today 13:00:35

Hey, thanks for the reply.

Lone_Wolf wrote:

Both speedtest.net and fast.com report
What latency did they report and are download and upload same speed ?

My connection is advertised as 1000/500 so:
Fast.com: dl -> 920mbps, up -> 370. latency "unloaded" 2m, "loaded": 7ms
speedtest.net: 912/465. latency 12ms for download and upload.

Lone_Wolf wrote:

Please post the outputs of
$ ip a
$ ip route
$ ip -6 route
from the router.

root@OpenWrt:~# ip a 
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1504 qdisc mq state UP qlen 1000
    link/ether my:public:ipv6:address brd ff:ff:ff:ff:ff:ff
    inet6 fe80::82af:xxxx:xxxx:xxxx/64 scope link 
       valid_lft forever preferred_lft forever
3: wan@eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP qlen 1000
    link/ether my:public:ipv6:address brd ff:ff:ff:ff:ff:ff
    inet6 my:routers:my:address1/64 scope link 
       valid_lft forever preferred_lft forever
4: lan1@eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-lan state UP qlen 1000
    link/ether my:public:ipv6:address brd ff:ff:ff:ff:ff:ff
5: lan2@eth0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue master br-lan state LOWERLAYERDOWN qlen 1000
    link/ether my:public:ipv6:address brd ff:ff:ff:ff:ff:ff
6: lan3@eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-lan state UP qlen 1000
    link/ether my:public:ipv6:address brd ff:ff:ff:ff:ff:ff
7: lan4@eth0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue master br-lan state LOWERLAYERDOWN qlen 1000
    link/ether my:public:ipv6:address brd ff:ff:ff:ff:ff:ff
8: br-lan: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP qlen 1000
    link/ether my:public:ipv6:address brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.1/24 brd 192.168.1.255 scope global br-lan
       valid_lft forever preferred_lft forever
    inet6 2a02:my:other:public:ipv6:iguess/60 scope global dynamic noprefixroute 
       valid_lft 44434sec preferred_lft 44434sec
    inet6 fdc3:other:public:addresses/60 scope global noprefixroute 
       valid_lft forever preferred_lft forever
    inet6 fe80::82af:xxxx:xxxx:xxxx/64 scope link 
       valid_lft forever preferred_lft forever
9: wan.835@wan: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1492 qdisc noqueue state UP qlen 1000
    link/ether my:public:ipv6:address brd ff:ff:ff:ff:ff:ff
    inet6 my:routers:my:address1/64 scope link 
       valid_lft forever preferred_lft forever
10: br-guest: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP qlen 1000
    link/ether my:public:ipv6:address brd ff:ff:ff:ff:ff:ff
    inet 192.168.3.1/24 brd 192.168.3.255 scope global br-guest
       valid_lft forever preferred_lft forever
    inet6 my:routers:mac:address2/64 scope link 
       valid_lft forever preferred_lft forever
11: phy1-ap0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-guest state UP qlen 1000
    link/ether my:raw:mac:address brd ff:ff:ff:ff:ff:ff
12: phy0-ap0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-guest state UP qlen 1000
    link/ether my:public:ipv6:address brd ff:ff:ff:ff:ff:ff
15: pppoe-wan: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1484 qdisc fq_codel state UNKNOWN qlen 3
    link/ppp 
    inet public.ipv4.162.153 peer public.ipv4.125.100/32 scope global pppoe-wan
       valid_lft forever preferred_lft forever
    inet6 other::public:addresses_fe:12b2:d964:e16b:9777:bc8f/64 scope global dynamic noprefixroute 
       valid_lft 2591908sec preferred_lft 604708sec
    inet6 fe80::d96a::yet:another:address/128 scope link flags 02 
       valid_lft forever preferred_lft forever
root@OpenWrt:~# ip route 
default via public.ipv4.125.100 dev pppoe-wan 
public.ipv4.125.100 dev pppoe-wan scope link  src public.ipv4.162.153 
192.168.1.0/24 dev br-lan scope link  src 192.168.1.1 
192.168.3.0/24 dev br-guest scope link  src 192.168.3.1 
root@OpenWrt:~# ip -6 route
default from 2a02:probably:primary:address:from:isp::/56 via fe80::aede::router::address dev pppoe-wan  metric 512 
default from other::public:addresses_fe:12b2::/64 via fe80::aede::router::address dev pppoe-wan  metric 512 
other::public:addresses_10:2204::/62 via another:ipv6:routing:address dev br-lan  metric 1024 
2a02:probably:primary:address:from:isp::/64 dev br-lan  metric 1024 
other::public:addresses_16:604::/62 via another:ipv6:routing:address dev br-lan  metric 1024 
unreachable 2a02:probably:primary:address:from:isp::/56 dev lo  metric 2147483647 
other::public:addresses_1a:e04::/62 via another:ipv6:routing:address dev br-lan  metric 1024 
unreachable other::public:addresses_fe:12b2::/64 dev lo  metric 2147483647 
fdc3:other:public:addresses/64 dev br-lan  metric 1024 
fdc3:other:public:addresses/62 via another:ipv6:routing:address dev br-lan  metric 1024 
unreachable fdc3:other:public:addresses/48 dev lo  metric 2147483647 
fe80::aede::router::address dev pppoe-wan  metric 256 
fe80::d96a::yet:another:address dev pppoe-wan  metric 256 
fe80::/64 dev eth0  metric 256 
fe80::/64 dev br-guest  metric 256 
fe80::/64 dev br-lan  metric 256 
fe80::/64 dev wan  metric 256 
fe80::/64 dev wan.835  metric 256 
anycast 2a02:probably:primary:address:from:isp:: dev br-lan  metric 0 
anycast other::public:addresses_fe:12b2:: dev pppoe-wan  metric 0 
anycast my:local:prefix:: dev br-lan  metric 0 
anycast fe80:: dev eth0  metric 0 
anycast fe80:: dev br-guest  metric 0 
anycast fe80:: dev br-lan  metric 0 
anycast fe80:: dev wan.835  metric 0 
anycast fe80:: dev wan  metric 0 
multicast ff00::/8 dev eth0  metric 256 
multicast ff00::/8 dev br-lan  metric 256 
multicast ff00::/8 dev br-guest  metric 256 
multicast ff00::/8 dev wan  metric 256 
multicast ff00::/8 dev wan.835  metric 256 
multicast ff00::/8 dev pppoe-wan  metric 256

Also when i initially installed the ftth all i did was create a new wan.865 device (mtu 1492) as my ISP requires specific tagging. Then a new PPPoE-wan interface with my ISP provided credentials and finally on the firewall tab i did "software flow offloading" (speeds were slow everywhere without this). I was actually surprised that it was that easy, maybe i messed up somewhere. On the other hand only Steam is having issues and also other devices on the same network don't have issues.

Lone_Wolf · Today 13:51:15

One thing I considered was whether CGNAT was involved (yes, there are fiber providers that use that) but you have many public ip-addresses.

Please post the output of the same commands but this time from the troublesome device.

Moderator Note
moving to Networking, Server, and Protection

Arch Linux

#1 Yesterday 09:13:20

Slow Steam download speed after switching from vdsl to ftth

#2 Yesterday 13:35:42

Re: Slow Steam download speed after switching from vdsl to ftth

#3 Today 13:00:35

Re: Slow Steam download speed after switching from vdsl to ftth

#4 Today 13:51:15

Re: Slow Steam download speed after switching from vdsl to ftth

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