My ISP supports this how can I enable it please? I tried setting 1508 MTU on eth0 but all lan posts disabled until the changes auto reverted and I rebooted router. Connection is PPPoE on VLAN 911 IPv4 and IPv6.
C:\Windows\System32>ping -f -l 1472 8.8.8.8
Pinging 8.8.8.8 with 1472 bytes of data:
Reply from 192.168.1.1: Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.
Ping statistics for 8.8.8.8:
Packets: Sent = 4, Received = 1, Lost = 3 (75% loss),
NETWORK
config interface 'loopback'
option device 'lo'
option proto 'static'
option ipaddr '127.0.0.1'
option netmask '255.0.0.0'
config globals 'globals'
option ula_prefix 'REDACTED'
option packet_steering '1'
config device
option name 'br-lan'
option type 'bridge'
list ports 'lan1'
list ports 'lan2'
list ports 'lan3'
list ports 'lan4'
list ports 'lan5'
config interface 'lan'
option device 'br-lan'
option proto 'static'
option ipaddr '192.168.1.1'
option netmask '255.255.255.0'
option ip6assign '60'
config interface 'wan'
option device 'eth1.911'
option proto 'pppoe'
option username 'REDACTED'
option password 'REDACTED'
option ipv6 'auto'
option peerdns '0'
list dns '1.1.1.1'
list dns '1.0.0.1'
list dns '2606:4700:4700::1111'
list dns '2606:4700:4700::1001'
config interface 'wan6'
option device 'eth1.911'
option proto 'dhcpv6'
option reqaddress 'try'
option reqprefix 'auto'
option norelease '1'
option peerdns '0'
list dns '2606:4700:4700::1111'
list dns '2606:4700:4700::1001'
config device
option type '8021q'
option ifname 'eth1'
option vid '911'
option name 'eth1.911'
Please connect to your OpenWrt device using ssh and copy the output of the following commands and post it here using the "Preformatted text </> " button:
Remember to redact passwords, MAC addresses and any public IP addresses you may have:
ubus call system board
cat /etc/config/network
cat /etc/config/dhcp
cat /etc/config/firewall
As I understand it with PPPoE due to protocol over head max MTU is 1492 but if your ISP supports baby jumbo fames, which they stay they do, and the router supports RFC 4638 which OpenWRT apparently does then you can increas max MTU to 1500. So I need to change MTU on the WAN interface to 1508 and it should give a max MTU of 1500. I'm not sure where/what to edit to change the MTU to 1508.
Did I enable ppp debug correctly I see nothing in the system log, rebooted router too still nothing. Is there another log somewhere?
config interface 'wan'
option device 'eth1.911'
option proto 'pppoe'
option username 'REDACTED'
option password 'REDACTED'
option ipv6 'auto'
option peerdns '0'
list dns '1.1.1.1'
list dns '1.0.0.1'
list dns '2606:4700:4700::1111'
list dns '2606:4700:4700::1001'
option pppd_options 'debug'
Not quite... the PPPoE header lives inside the ethernet payload. The result of that is that the typical MTU of the PPPOE tunnel is 1500, but traffic going through that tunnel will not see the PPPoE header but will still be limited by the available payload capacity through the tunnel.
The effect is that for traffic going through that tunnel it appears as if the maximum MTU that goes through without requiring fragmentaion is 1500-8=1492 bytes. BUT the actual MTU on the ethernet interface carrying the PPPOE traffic needs to be set to 1500 only the MTU of the PPPoE interface (on OpenWrt typically pppoe-wan) needs to be set to 1492 (as far as I know this will be performed automatically).
To allow baby-jumbo frames you need to do two things (which might or might not be supported by your router):
a) increase the MTU of the ethernet interface cayying the PPPoE traffic by 8 bytes (with DSA you occasionally see an interface MTU of 1504, in that case IIRC adjust to 1512, otherwise 1508)
b) increase the MTU on the PPPoE interface to 1500 bytes. Note your ISP also has to play ball for this to work, some do, some do not.
Thanks but no dice. I changed eth0 from 1504 to 1512 at luci/network/devices save and apply then this is what happens
all ethernet ports are disabled
applying configuration changes counts down to 0
Failed to confirm settings message
Have to power cycle router to get ports working again
My ISP does not support IPv6, so I am not sure about that part, but as far as IPv4 goes, here is the config that should work for you (I see that eth1 is your WAN interface).
config device
option name 'eth1'
option mtu '1508'
config interface 'wan'
option device 'eth1.911'
option proto 'pppoe'
option username 'XXXXXXXX'
option password 'XXXXXXXX'
option ipv6 '0'
option peerdns '0'
option mtu '1508'
list dns 'X.X.X.X'
list dns 'X.X.X.X'
You need to use eth1 instead. Once you add a new device section as per above, it will no longer be greyed out. You can add a device by editing /etc/config/network or by hitting that Configure ... button and setting up mtu on the interface (I think). I rarely use UI, so not sure.
I do not have this section and am also using VLAN tagging. Can you try removing it? It is not needed and might be getting in the way.
UPDATE: I noticed that just reloading config is not enough for these changes to take effect: I had to reboot the router every time I made changes when trying to figure this out.
Thanks that's done it. Was confused thought WAN was eth0.
ping -f -l 1472 8.8.8.8
Pinging 8.8.8.8 with 1472 bytes of data:
Reply from 8.8.8.8: bytes=1472 time=5ms TTL=118
Reply from 8.8.8.8: bytes=1472 time=5ms TTL=118
Reply from 8.8.8.8: bytes=1472 time=5ms TTL=118
Reply from 8.8.8.8: bytes=1472 time=5ms TTL=118
Ping statistics for 8.8.8.8:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 5ms, Maximum = 5ms, Average = 5ms
Here's the full working config.
config interface 'loopback'
option device 'lo'
option proto 'static'
option ipaddr '127.0.0.1'
option netmask '255.0.0.0'
config globals 'globals'
option ula_prefix 'REDACTED'
option packet_steering '1'
config device
option name 'br-lan'
option type 'bridge'
list ports 'lan1'
list ports 'lan2'
list ports 'lan3'
list ports 'lan4'
list ports 'lan5'
config interface 'lan'
option device 'br-lan'
option proto 'static'
option ipaddr '192.168.1.1'
option netmask '255.255.255.0'
option ip6assign '60'
config device
option name 'eth1'
option mtu '1508'
config interface 'wan'
option device 'eth1.911'
option proto 'pppoe'
option username 'REDACTED'
option password 'REDACTED'
option ipv6 'auto'
option peerdns '0'
option mtu '1508'
list dns '1.1.1.1'
list dns '1.0.0.1'
list dns '2606:4700:4700::1111'
list dns '2606:4700:4700::1001'
config interface 'wan6'
option device 'eth1.911'
option proto 'dhcpv6'
option reqaddress 'try'
option reqprefix 'auto'
option norelease '1'
option peerdns '0'
list dns '2606:4700:4700::1111'
list dns '2606:4700:4700::1001'
config device
option type '8021q'
option ifname 'eth1'
option vid '911'
option name 'eth1.911'
That's what was added when I setup the VLAN in the UI. I don't see VLAN 911 referenced anywhere else so it would probably break the connection if I remove that wouldn't it? I can try though if your curious.
I ran /etc/init.d/network restart for changes to take effect. Effectively the same as reboot I suppose.
Your device supports DSA config, yes?
Where in the world are you and most of New folks teached about 8021q configs??
With DSA and even most of old swconfig you do not need those.
I'm curious and wondering because it comes up far to frequently and introduces so much of confusion and bonkers configs...
