Network uses the default mtu values if public/private mtu are not set

[weizhouapache]

There are two global settings for mtu size

• vr.private.interface.max.mtu
• vr.public.interface.max.mtu

however, when I create a VPC tier without specified mtu, the VPC tier is created with default private mtu (1500) .
It should use the mtu size in the global settings if not set in api parameters of createNetwork api.

Please note:
isolated networks do not have the issue

ISSUE TYPE

• Bug Report

COMPONENT NAME

CLOUDSTACK VERSION

4.20, the same issue should exist in 4.19 as well.

CONFIGURATION

OS / ENVIRONMENT

SUMMARY

STEPS TO REPRODUCE

EXPECTED RESULTS

ACTUAL RESULTS

[weizhouapache]

fixed by #10257