We were able to resolve the issue by setting the IP statically on the XCP-ng node(I believe a reboot was also required). That updated the console's URI and it was working again in XCP-ng Center and XO.

Would it be possible for XCP-ng XAPI to read and return, for example, the addresses contained in the [/etc/hosts] file? In this case, if we put both the local IP and the external address used to access NAT on /etc/hosts and do a careful reading and interpretation of its content, it would act analogously to a DNS to translate both the local address and the external to XAPI.

Could it be that when implementing a change like this in XCP-Ng, would XAPI work under NAT?

So if you XO can't reach this IP, console connection can't work.

There's any special configuration to work under NAT?

However, setting static IP address did not work to fix it. Had to reinstall, setting a static IP at re-installation time.

We were able to resolve the issue by setting the IP statically on the XCP-ng node(I believe a reboot was also required). That updated the console's URI and it was working again in XCP-ng Center and XO.

 egrep -R '(10\.40\.|192\.168\.)'  /etc

Like grep -R 'IP-Address' /etc

[23:59 xen-B xcp]# pushd /var/lib/xcp/
[23:59 xen-B xcp]# systemctl stop xapi
[23:59 xen-B xcp]# cp state.db ./state-YYYYMMDD-HHMM.db
[23:59 xen-B xcp]# egrep  '(192.168.2.141)' ./state.db | wc
      1   11757  454034
[23:59 xen-B xcp]# echo " :( 1 line with over 11,000 words :(" 
[23:59 xen-B xcp]# xmllint --format state.db >> state.xmllint--pretty.db
[23:59 xen-B xcp]# egrep  '(192.168.2.141)' ./state.db | wc
     10     193   13526
[23:59 xen-B xcp]# echo "i can deal with 193 words :) and edited with vi" 
[23:59 xen-B xcp]# mv state.xmllint--pretty.db ./state.db
[23:59 xen-B xcp]# systemctl start xapi

xe console-list indicates the the proper IP addresses:

[23:59 xen-B xcp]# xe console-list  vm-name-label=Control\ domain\ on\ host:\ xen-B

uuid ( RO)             : d5039d1a-64ad-c8a9-a309-51e568ba2926
          vm-uuid ( RO): 1593da28-8e85-4252-878e-778eb414c549
    vm-name-label ( RO): Control domain on host: xen-B
         protocol ( RO): VT100
         location ( RO): https://192.168.10.192/console?ref=OpaqueRef:7be93ca1-76cf-4649-8276-74891eac0a06


uuid ( RO)             : 7bcf725e-ae83-cf6f-7997-7dd63469929f
          vm-uuid ( RO): 1593da28-8e85-4252-878e-778eb414c549
    vm-name-label ( RO): Control domain on host: xen-B
         protocol ( RO): RFB
         location ( RO): https://192.168.10.192/console?ref=OpaqueRef:1361b935-2d25-4929-9b27-4b0483cbb0f7


[00:00 xen-B xcp]# ip a show dev xenbr0 | egrep inet
    inet 192.168.10.192/16 brd 192.168.255.255 scope global dynamic xenbr0

But there is still a blank host console in both XOA and xcp center. Suppose those OpaqueRefs have to be fixed up as well. EFI starting crashing on this r720, so having many other severe issues to deal with.

1. Stop XAPI service on all hosts of the pool
2. Copy /var/xapi/state.db somewhere else in case
3. Edit it, and find the bad IP, replace it with the right one
4. Save
5. Start XAPI on all hosts, master first

[02:37 xcp-ng-G ~]# xe console-param-clear param-name=location uuid=fb69931e-ae2b-c2d3-dbce-3e9a9ae57646
Error: Can only clear RW parameters

[02:38 xcp-ng-G ~]# xe console-param-clear uuid=12aae74a-4d4f-7ed3-976d-b36e0ae1905d param-name=location
Error: Can only clear RW parameters

[02:38 xcp-ng-G ~]# xe console-param-remove uuid=12aae74a-4d4f-7ed3-976d-b36e0ae1905d param-key=location param-name=location
Error: Can only remove from parameters of type Set or Map

[02:38 xcp-ng-G ~]# xe console-param-set uuid=12aae74a-4d4f-7ed3-976d-b36e0ae1905d

Is there some way to blow these old Dom0 consoles away?

[01:23 eceoxen-B ~]# xe console-list vm-name-label=Control\ domain\ on\ host:\ eceoxen-B
uuid ( RO)             : d5039d1a-64ad-c8a9-a309-51e568ba2926
          vm-uuid ( RO): 1593da28-8e85-4252-878e-778eb414c549
    vm-name-label ( RO): Control domain on host: eceoxen-B
         protocol ( RO): VT100
         location ( RO): https://192.168.2.141/console?ref=OpaqueRef:7be93ca1-76cf-4649-8276-74891eac0a06

uuid ( RO)             : 7bcf725e-ae83-cf6f-7997-7dd63469929f
          vm-uuid ( RO): 1593da28-8e85-4252-878e-778eb414c549
    vm-name-label ( RO): Control domain on host: eceoxen-B
         protocol ( RO): RFB
         location ( RO): https://192.168.2.141/console?ref=OpaqueRef:1361b935-2d25-4929-9b27-4b0483cbb0f7

[01:25 eceoxen-B ~]# ip a show  | egrep inet | egrep -v '(inet 127)'
    inet 192.168.10.192/16 brd 192.168.255.255 scope global dynamic xenbr0

192.168.10.193 != 192.168.10.192 Control domain consoles are still using a very very old IP address totally different than the statically leased DHCP address of Dom0. Even after an emergency network reset. Cannot delete this VM. The location parameter is ReadOnly, so i cannot delete it. I am going to try another Emergency Network Reset and set the static lease as a static IP address. If that does not work, is there a way to blow away these bad consoles or at least the IP addresses?

Because i knew i would wipe the machine and start over fresh anyway, i tried to save time by using DHCP.

Can you share your server specs so we can try to find a pattern?

I can ssh into the server and run xscenter and it works fine, but can't use XCP-ng Center 8.0.1 to see the console.

The consoles for the various VMs I have running work fine. No NAT involved, everything on same subnet.