EA8300/ipq40xx - Can MTU be changed?

Installing and Using OpenWrt
1

Hello,

I’m trying to set up batman-adv and in doing so I wish to set the MTU on the wan interface to 1532. I tried doing this on both the wan and the eth0. Both attempts caused me to lose access to the device. Is this possible on this switch, or do I have to live with 1500?

Thanks,
tyami94

Update: I just tried using iproute2 to set the MTU and this works fine? It only seems to explode when I use LuCI. Any ideas?

Update 2: I just tried setting the MTU on the wan interface again through LuCI after realizing (through my experiment with iproute2) that eth0's MTU would also be set as a side-effect, and now it works. I don't know what was happening before.

1 Like
2

You have to start with outher encapsulating device.
if the devices are in form wan@eth0, lan1@eth0 etc then eth0 has to be increased first. Starting with ifconfig / ip just to assess stability. Dont take my workd but ipqxxxx eth0 supports 8k-X (some encap is added to manage switch) MTU without changing any sub-devices MTU.

Same for any bridges involved. If you want a clean 9000 jumbo on a PC with many netcards first your bri-lan must be set to 9000 then members (there is no encap)

Do for starters - let this settle for a day

ifconfig eth0 mtu 8000

before fixing that parameter in luci