Pakfire Problem with Upstream proxy

Hello I have an interesting problem here when retrieving updates via Pakfire, this retrieves its updates behind another IPFire, incl. URLFilter.

IPFire A:

Feb 16 15:17:58 prx-es-01 pakfire: DOWNLOAD INFO: 2.25-x86_64/lists/server-list.db has size of 3465 bytes
Feb 16 15:17:58 prx-es-01 pakfire: DOWNLOAD INFO: HTTP-Status-Code: 501 - 501 Not Implemented
Feb 16 15:17:58 prx-es-01 pakfire: DOWNLOAD ERROR: 501 Not Implemented
Feb 16 15:17:58 prx-es-01 pakfire: DOWNLOAD INFO: Host: pakfire.ipfire.org (HTTPS) - File: 2.25-x86_64/lists/server-list.db
Feb 16 15:17:58 prx-es-01 pakfire: DOWNLOAD INFO: Upstream proxy: 10.46.1.3:3128
Feb 16 15:17:58 prx-es-01 pakfire: DOWNLOAD INFO: 2.25-x86_64/lists/server-list.db has size of 3465 bytes
Feb 16 15:17:58 prx-es-01 pakfire: DOWNLOAD INFO: HTTP-Status-Code: 501 - 501 Not Implemented
Feb 16 15:17:58 prx-es-01 pakfire: DOWNLOAD ERROR: 501 Not Implemented
Feb 16 15:17:58 prx-es-01 pakfire: DOWNLOAD INFO: Host: pakfire.ipfire.org (HTTPS) - File: 2.25-x86_64/lists/server-list.db
Feb 16 15:17:58 prx-es-01 pakfire: DOWNLOAD INFO: Upstream proxy: 10.46.1.3:3128
Feb 16 15:17:58 prx-es-01 pakfire: DOWNLOAD INFO: 2.25-x86_64/lists/server-list.db has size of 3465 bytes
Feb 16 15:17:58 prx-es-01 pakfire: DOWNLOAD INFO: HTTP-Status-Code: 501 - 501 Not Implemented
Feb 16 15:17:58 prx-es-01 pakfire: DOWNLOAD ERROR: 501 Not Implemented
Feb 16 15:17:58 prx-es-01 pakfire: DOWNLOAD INFO: Host: pakfire.ipfire.org (HTTPS) - File: 2.25-x86_64/lists/server-list.db
Feb 16 15:17:58 prx-es-01 pakfire: DOWNLOAD INFO: Upstream proxy: 10.46.1.3:3128
Feb 16 15:17:58 prx-es-01 pakfire: DOWNLOAD INFO: 2.25-x86_64/lists/server-list.db has size of 3465 bytes
Feb 16 15:17:58 prx-es-01 pakfire: DOWNLOAD INFO: HTTP-Status-Code: 501 - 501 Not Implemented
Feb 16 15:17:58 prx-es-01 pakfire: DOWNLOAD ERROR: 501 Not Implemented
Feb 16 15:17:58 prx-es-01 pakfire: DOWNLOAD INFO: Host: pakfire.ipfire.org (HTTPS) - File: 2.25-x86_64/lists/server-list.db

IPFire Upstream:

613727009.359      0 10.47.0.2 NONE/501 320 HEAD https://pakfire.ipfire.org/2.25-x86_64/lists/server-list.db - HIER_NONE/- text/html
1613727009.440      0 10.47.0.2 NONE/501 3784 GET https://pakfire.ipfire.org/2.25-x86_64/lists/server-list.db - HIER_NONE/- text/html
1613727009.521      0 10.47.0.2 NONE/501 320 HEAD https://pakfire.ipfire.org/2.25-x86_64/lists/server-list.db - HIER_NONE/- text/html
1613727009.578      0 10.47.0.2 NONE/501 3784 GET https://pakfire.ipfire.org/2.25-x86_64/lists/server-list.db - HIER_NONE/- text/html
1613727009.641      0 10.47.0.2 NONE/501 320 HEAD https://pakfire.ipfire.org/2.25-x86_64/lists/server-list.db - HIER_NONE/- text/html
1613727009.700      0 10.47.0.2 NONE/501 3784 GET https://pakfire.ipfire.org/2.25-x86_64/lists/server-list.db - HIER_NONE/- text/html
1613727009.785      0 10.47.0.2 NONE/501 320 HEAD https://pakfire.ipfire.org/2.25-x86_64/lists/server-list.db - HIER_NONE/- text/html
1613727009.870      0 10.47.0.2 NONE/501 3784 GET https://pakfire.ipfire.org/2.25-    x86_64/lists/server-list.db - HIER_NONE/- text/html
1613727009.954      0 10.47.0.2 NONE/501 320 HEAD https://pakfire.ipfire.org/2.25-    x86_64/lists/server-list.db - HIER_NONE/- text/html
1613727010.033      0 10.47.0.2 NONE/501 3784 GET https://pakfire.ipfire.org/2.25-x86_64/lists/server-list.db - HIER_NONE/- text/html
1613727010.126      0 10.47.0.2 NONE/501 320 HEAD https://firemirror.scp-systems.ch/pakfire2/2.25-x86_64/lists/packages_list.db - HIER_NONE/- text/html
1613727010.207      0 10.47.0.2 NONE/501 3840 GET https://firemirror.scp-systems.ch/pakfire2/2.25-x86_64/lists/packages_list.db - HIER_NONE/- text/html
1613727010.300      0 10.47.0.2 NONE/501 320 HEAD https://mirror7.ipfire.org/pakfire2/2.25-x86_64/lists/packages_list.db - HIER_NONE/- text/html
1613727010.381      0 10.47.0.2 NONE/501 3819 GET https://mirror7.ipfire.org/pakfire2/2.25-x86_64/lists/packages_list.db - HIER_NONE/- text/html
1613727010.465      0 10.47.0.2 NONE/501 320 HEAD https://mirror.csclub.uwaterloo.ca/ipfire/pakfire2/2.25-x86_64/lists/packages_list.db - HIER_NONE/- text/html
1613727010.804      0 10.47.0.2 NONE/501 3866 GET https://mirror.csclub.uwaterloo.ca/ipfire/pakfire2/2.25-x86_64/lists/packages_list.db - HIER_NONE/- text/html
1613727010.875      0 10.47.0.2 NONE/501 320 HEAD https://uk.mirrors.fossho.st/ipfire/pakfire2/2.25-x86_64/lists/packages_list.db - HIER_NONE/- text/html
1613727010.932      0 10.47.0.2 NONE/501 3848 GET https://uk.mirrors.fossho.st/ipfire/pakfire2/2.25-x86_64/lists/packages_list.db - HIER_NONE/- text/html
1613727011.006      0 10.47.0.2 NONE/501 320 HEAD https://mirror.aarnet.edu.au/pub/ipfire/pakfire2/2.25-x86_64/lists/packages_list.db - HIER_NONE/- text/html
1613727011.069      0 10.47.0.2 NONE/501 3862 GET https://mirror.aarnet.edu.au/pub/ipfire/pakfire2/2.25-x86_64/lists/packages_list.db - HIER_NONE/- text/html
1613727011.160      0 10.47.0.2 NONE/501 320 HEAD https://mirror7.ipfire.org/pakfire2/2.25-x86_64/lists/core-list.db - HIER_NONE/- text/html
1613727011.220      0 10.47.0.2 NONE/501 3807 GET https://mirror7.ipfire.org/pakfire2/2.25-x86_64/lists/core-list.db - HIER_NONE/- text/html
1613727011.294      0 10.47.0.2 NONE/501 320 HEAD https://ipfire.mirror.ac.za/pakfire2/2.25-x86_64/lists/core-list.db - HIER_NONE/- text/html
1613727011.359      0 10.47.0.2 NONE/501 3810 GET https://ipfire.mirror.ac.za/pakfire2/2.25-x86_64/lists/core-list.db - HIER_NONE/- text/html
1613727011.429      0 10.47.0.2 NONE/501 320 HEAD https://mirror.cedia.org.ec/ipfire/pakfire2/2.25-x86_64/lists/core-list.db - HIER_NONE/- text/html
1613727011.496      0 10.47.0.2 NONE/501 3833 GET https://mirror.cedia.org.ec/ipfire/pakfire2/2.25-x86_64/lists/core-list.db - HIER_NONE/- text/html
1613727011.568      0 10.47.0.2 NONE/501 320 HEAD https://uk.mirrors.fossho.st/ipfire/pakfire2/2.25-x86_64/lists/core-list.db - HIER_NONE/- text/html
1613727011.633      0 10.47.0.2 NONE/501 3836 GET https://uk.mirrors.fossho.st/ipfire/pakfire2/2.25-x86_64/lists/core-list.db - HIER_NONE/- text/html
1613727011.701      0 10.47.0.2 NONE/501 320 HEAD https://mirror.uta.edu.ec/ipfire/pakfire2/2.25-x86_64/lists/core-list.db - HIER_NONE/- text/html
1613727011.777      0 10.47.0.2 NONE/501 3827 GET https://mirror.uta.edu.ec/ipfire/pakfire2/2.25-x86_64/lists/core-list.db - HIER_NONE/- text/html

HTTP Error code 501 implies:

The server does not support the functionality required to fulfill the request. This is the appropriate response when the server does not recognize the request method and is not capable of supporting it for any resource.

Interestingly, your IPFire Upstream is getting the same HTTP error code response :thinking:
Really unusual, did pakfire updates work properly before? Are you sure the IPFire Upstream can really reach the destination pakfire mirrors?

The Upstream IPFire have no Problems with the Update, he can update his Update-List without Problems.
If I remove the upstream server from the other IPFire, it also works without problems.