fighting with MTU on VirtualBox

[nickbash11]

I noticed that there is a ticket with number 30, but I am not sure that it is a relative.

My problem revealed on Virtualbox's OpenWrt 19 x86_64, where the packets with size more than 1448 bytes do not reach other node, and I just increased MTU of device up to 1536. It is a rough hack and I hope this problem can be fixed another way.

Correct me if I made a mistake:

/etc/config/network

---cut---
config device 'eth0_mtu1536'
    option name 'eth0'
    option mtu '1536'

config device 'eth0_30'
    option type '8021ad'
    option name 'eth0_30'
    option ifname 'eth0'
    option vid '30'

config interface 'eth0_30_ad'
    option ifname 'eth0_30'
    option auto '1'
---cut---

/etc/config/bmx7

config 'plugin'
        option 'plugin' 'bmx7_config.so'

config 'plugin'
        option 'plugin' 'bmx7_json.so'

config 'plugin'
        option 'plugin' 'bmx7_sms.so'

config 'dev' 'mesh_1'
        option 'dev' 'eth0_30'

config 'plugin'
        option 'plugin' 'bmx7_tun.so'

config tunDev 'tmain'
    option tunDev 'tmain'
    option tun4Address '172.16.1.1/32'

config tunOut 'cloud'
    option tunOut 'cloud'
    option network '172.16.0.0/16'
    option minPrefixLen '24'

/etc/openwrt_release

DISTRIB_ID='OpenWrt'
DISTRIB_RELEASE='19.07.4'
DISTRIB_REVISION='r11208-ce6496d796'
DISTRIB_TARGET='x86/64'
DISTRIB_ARCH='x86_64'
DISTRIB_DESCRIPTION='OpenWrt 19.07.4 r11208-ce6496d796'
DISTRIB_TAINTS=''