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Topic: Set MTU for wireless interface (particulatly bridged one)

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Post #1
broucari
29 Aug 2015, 14:51

How can I set the mtu for a bridge ?  I need first to set the mtu of each downstream interface then to the bridge (manually it work doing ifoncifg interface mtu 2000).

I have tried something like this but it does not work (setting LAN_V20 to mtu 2000)

/etc/config/network

config interface 'loopback'
    option ifname 'lo'
    option proto 'static'
    option ipaddr '127.0.0.1'
    option netmask '255.0.0.0'

config globals 'globals'
    option ula_prefix 'fd02:15b3:9237::/48'

config interface 'INTERFACE_ETH1'
    option proto 'none'
    option auto '1'
    option ifname 'eth1'
    option mtu '4000'

config interface 'BRIDGE_V1'
    option type 'bridge'
    option proto 'none'
    option auto '1'
    option stp '1'
    option _orig_ifname 'eth1 wlan1'
    option _orig_bridge 'true'
    option ifname 'eth1'
    option mtu '1500'

config interface 'LAN_V1'
    option force_link '1'
    option proto 'static'
    option ipaddr '192.168.1.1'
    option netmask '255.255.255.0'
    option _orig_ifname 'eth1'
    option _orig_bridge 'false'
    option ifname 'br-BRIDGE_V1'
    option mtu '1500'

config interface 'BRIDGE_V20'
    option type 'bridge'
    option proto 'none'
    option ifname 'eth1.20'
    option auto '1'
    option stp '1'
    option mtu '1500'

config interface 'SWITCH_V100'
    option type 'bridge'
    option proto 'none'
    option ifname 'eth1.100'
    option auto '1'
    option mtu '1500'

config interface 'LAN_V20'
    option proto 'static'
    option ifname 'br-BRIDGE_V20'
    option netmask '255.255.255.0'
    option ipaddr '192.168.20.1'

config interface 'WAN'
    option ifname 'eth0'
    option proto 'dhcp'

config interface 'WAN_6M'
    option ifname 'eth0'
    option _orig_ifname 'eth0'
    option _orig_bridge 'false'
    option proto 'static'
    option ip6addr '2a01:e35:2f01:a60::2/64'
    option ip6gw 'fe80::6aa3:78ff:fe1c:2b77'
    option ip6prefix '2A01:E35:2F01:A60::/61'

config switch
    option name 'switch0'
    option reset '1'
    option enable_vlan '1'
    option mirror_source_port '0'
    option mirror_monitor_port '0'

config switch_vlan
    option device 'switch0'
    option vlan '1'
    option vid '1'
    option ports '0 2'

config switch_vlan
    option device 'switch0'
    option vlan '2'
    option ports '1 6'
    option vid '2'

config switch_vlan
    option device 'switch0'
    option vlan '3'
    option ports '0t 1t 2t 3t 6t'
    option vid '100'

config switch_vlan
    option device 'switch0'
    option vlan '4'
    option vid '101'
    option ports '0t 3'

config interface 'BRIDGE_V200'
    option type 'bridge'
    option proto 'none'
    option ifname 'eth1.200'
    option auto '1'
    option stp '1'
    option mtu '1500'

config interface 'LAN_V200'
    option proto 'static'
    option ifname 'br-BRIDGE_V200'
    option ipaddr '192.168.200.1'
    option netmask '255.255.255.0'

config switch_vlan
    option device 'switch0'
    option vlan '5'
    option vid '20'
    option ports '0t 4t 5t'

config interface 'LAN_V20_6'
    option proto 'static'
    option ifname 'br-BRIDGE_V20'
    option ip6addr '2a01:e35:2f01:a61::1/64'

config interface 'LAN_V20_6L'
    option proto 'static'
    option ifname 'br-BRIDGE_V20'
    option ip6addr 'fd02:15b3:9237:20::1/64'

config interface 'LAN_V200_6L'
    option proto 'static'
    option ifname 'br-BRIDGE_V200'
    option ip6addr 'FD02:15B3:9237:200::1/64'

config interface 'WAN_6D'
    option proto 'dhcpv6'
    option ifname 'eth0'
    option reqaddress 'try'
    option reqprefix 'auto'
    option master '1'

config interface 'A_EMERGENCY'
    option proto 'none'
    option ifname 'br-BRIDGE_V1'

config interface 'A_MAIN'
    option proto 'none'
    option ifname 'br-BRIDGE_V20'

config interface 'A_PRIVATE_OBJECT'
    option proto 'none'
    option _orig_ifname 'br-BRIDGE_200'
    option _orig_bridge 'false'
    option ifname 'br-BRIDGE_V200'

config interface 'BRIDGE_V101'
    option type 'bridge'
    option ifname 'eth1.101'
    option _orig_ifname 'eth1.101'
    option _orig_bridge 'true'
    option proto 'none'
    option mtu '1500'
    option stp '1'

config interface 'LAN_V101'
    option proto 'static'
    option ifname 'br-BRIDGE_V101'
    option ipaddr '192.168.101.1'
    option netmask '255.255.255.0'

config interface 'LAN_V101_6'
    option proto 'static'
    option ifname 'br-BRIDGE_V101'
    option ip6assign '64'
    option ip6hint '0'

And /etc/config/wireless

config wifi-device 'radio0'
    option type 'mac80211'
    option hwmode '11g'
    option path 'platform/qca955x_wmac'
    option htmode 'HT20'
    option channel '3'
    option country 'FR'
    option distance '10'
    option txpower '20'

config wifi-device 'radio1'
    option type 'mac80211'
    option channel '36'
    option hwmode '11a'
    option path 'pci0000:01/0000:01:00.0'
    option htmode 'VHT80'
    option txpower '17'
    option country 'FR'
    option distance '10'

config wifi-iface
    option device 'radio1'
    option mode 'ap'
    option wds '1'
    option network 'BRIDGE_V20'
    option encryption 'psk2+ccmp'
    option key 'XXXXXXXXXXXXXXX'
    option macaddr '02:16:3E:95:01:14'
    option ssid 'titikata_bridge_V20'

config wifi-iface
    option device 'radio0'
    option mode 'ap'
    option ssid 'Titikaka_SOS1'
    option encryption 'psk2+ccmp'
    option key 'XXXXXXXXXXXXXXX'
    option hidden '1'
    option network 'BRIDGE_V1'

config wifi-iface
    option device 'radio0'
    option mode 'ap'
    option ssid 'Titikaka_V20'
    option network 'BRIDGE_V20'
    option encryption 'psk2+ccmp'
    option key 'XXXXXXXXXXXXXXX'
    option wps_pushbutton '0'

config wifi-iface
    option device 'radio0'
    option mode 'ap'
    option network 'BRIDGE_V200'
    option encryption 'psk2+ccmp'
    option key 'XXXXXXXXXXXXXXX'
    option wps_pushbutton '0'
    option ssid 'Titikaka_V200'

Thanks

Bastien

Post #2
makarel
29 Aug 2015, 15:10

seems wifi doesnt have specific mtu option(maybe it gets the lan vlan mtu you bridged it to)
in your case BRIDGE_V1

http://wiki.openwrt.org/doc/uci/wireless

(Last edited by makarel on 29 Aug 2015, 15:12)

Post #3
broucari
29 Aug 2015, 15:40

I have tried to to increase the mtu of the bridge BRIDGE_V20. It does not work either.

Bastien

Post #4
makarel
29 Aug 2015, 17:55

i tryied on mine(AA) and cant change it either

Post #5
broucari
29 Aug 2015, 18:10

So bug. Opened #20425

Post #6
makarel
29 Aug 2015, 18:23

seems some older devices(mine also) cant handle mtu > 1500 and  in some builds mtu is locked wan<>lan
https://dev.openwrt.org/ticket/14148
i cant change mtu more or less then default 1500(i have wan pppoe.. autoconfigured mtu 1492); lan has mtu 1500

here it sais that per interface shouold work - but doesnt
https://lists.openwrt.org/pipermail/ope … 27941.html

and here .. manual config should work
https://www.gargoyle-router.com/phpbb/v … amp;t=1419

ifconfig eth0.1 mtu 1500

(Last edited by makarel on 29 Aug 2015, 18:33)

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