Hi Frank,

Thank you very much for the repid and detailed reply, here is my answer:

1) Notice 'gateway4' vs 'routes ...'
>> Yes, the default installation using the 'gateway4', but there is a warning popuped 'gateway4 has been deprecated' when I tried 'netplan apply' to generate the vlan interface. For eliminate this warning, I change 'gateway4' to 'routes' manually and 'apply' again, the warning disappeared but the vlan interface still not there. 

2) Do you have an openvswitch (ovs) in your environment? If so, how is it setup?
>> I don't think so, the only thing I've added was a 0.0.1000 OSA device and a vlan based on 0.0.1000, the vlan interface covers the IP addr.

3) Have you done any other network related (re-)configurations?
>> No, except the manual update in step 1)

4) Can you please perform a default installation w/o ovs?
>> I'll try this, but from my previous success trials on 20.04, 22.04... there were no ovs configure.

5) Could you also share the output of:
$ lszdev --online
>> 
[?2004hubuntu@ibm:~$ 
sudo lszdev --online
[?2004l
[sudo] password for ubuntu: 
 
TYPE       ID                                              ON   PERS  NAMES
zfcp-host  0.0.9000                                        yes  yes   
zfcp-host  0.0.9100                                        yes  yes   
zfcp-lun   0.0.9000:0x5001738030bb0141:0x0000000000000000  yes  yes   sg2
zfcp-lun   0.0.9000:0x5001738030bb0141:0x0001000000000000  yes  yes   sdb sg3
zfcp-lun   0.0.9000:0x5001738030bb0151:0x0000000000000000  yes  yes   sg0
zfcp-lun   0.0.9000:0x5001738030bb0151:0x0001000000000000  yes  yes   sda sg1
zfcp-lun   0.0.9100:0x5001738030bb0142:0x0000000000000000  yes  yes   sg4
zfcp-lun   0.0.9100:0x5001738030bb0142:0x0001000000000000  yes  yes   sdc sg5
zfcp-lun   0.0.9100:0x5001738030bb0152:0x0000000000000000  yes  yes   sg6
zfcp-lun   0.0.9100:0x5001738030bb0152:0x0001000000000000  yes  yes   sdd sg7
qeth       0.0.1000:0.0.1001:0.0.1002                      yes  yes   enc1000

6) Is your system a DPM system?
In case yes, can you also share:
sudo lszdev --auto-conf
>> Yes, 
[?2004hubuntu@ibm:~$ 
sudo lszdev --auto-conf
[?2004l
TYPE       ID                                              AUTO
zfcp-host  0.0.9000                                        yes
zfcp-host  0.0.9100                                        yes
zfcp-host  0.0.9200                                        yes
zfcp-host  0.0.9300                                        yes
zfcp-lun   0.0.9100:0x5001738030bb0142:0x0001000000000000  yes
qeth       0.0.1000:0.0.1001:0.0.1002                      yes


7) Can you please share the exact settings that you've specified in your early network configuration step?
>> I'll attach the full interaction messages in this ticket while installing. (ubuntu-23.04-install-osm)

8) Also also what you have specified in the semi-graphical (subiquity) installer screen?
>> Please see the screen shot 1 and 2 (network in subiquity 1.png; network in subiquity 2.png)

9) Please would you also share the entire /var/log/installer folder?
>> Zipped the folder and will attach it soon. (install.tar)

10) And thank you for the 'systemd-networkd-wait-online' sharing, I'll follow up your instruction.

Thanks~