ERR_CONNECTION_REFUSED accessing PMG web interface or Exchange OWA from Chrome

Help!
1

HAProxy version 2.4.22-0ubuntu0.22.04.3

Proxmox Mail Gateway behind it.

All works fine, but suddenly started getting an error “ERR_CONNECTION_REFUSED” in any browser at some PCs of my copmpany. Some PCs works well howerever.
At the same time if i open the PMG by IP it works well.

Please help me resolve this issue or teach me please how to find the reason of that error?

Thanks in advance.

UPD: actually i have Exchange 2019 behind the Haproxy too. And from time to time some PCs can’t access OWA with the exactly same error.
Help needed. Thanks.

image

2

Any help?

3

No one?

4

Please provides some HAProxy logs, it’s difficult to know what’s going on with just a browser screenshot, that could be anything like your firewall or your computer.

5

Actually, I’m not familiar with haproxy logging. All i saw when the error repeated:

Jun 17 17:35:23 localhost haproxy[671]: 192.168.21.72:56356 [17/Jun/2024:17:35:23.312] fe_ex2019~ be_ex2019_mapi/exch01 0/0/2/10/12 401 514 - - ---- 47/47/38/38/0 0/0 "POST /mapi/nspi/?MailboxId=4ce22e83-ca6b-47d0-9f69-02dc1024ef02@mydomain1.com HTTP/1.1"
Jun 17 17:35:23 localhost haproxy[671]: 192.168.21.72:56350 [17/Jun/2024:17:35:23.341] fe_ex2019~ be_ex2019_mapi/exch01 0/0/1/11/12 401 514 - - ---- 47/47/40/40/0 0/0 "POST /mapi/nspi/?MailboxId=9e62a900-a795-4204-972f-6d0ee1cdc563@mydomain2.com HTTP/1.1"
Jun 17 17:35:23 localhost haproxy[671]: 192.168.21.72:56353 [17/Jun/2024:17:35:23.345] fe_ex2019~ be_ex2019_mapi/exch01 0/0/7/13/20 401 514 - - ---- 47/47/40/40/0 0/0 "POST /mapi/nspi/?MailboxId=9e62a900-a795-4204-972f-6d0ee1cdc563@mydomain2.com HTTP/1.1"
Jun 17 17:35:23 localhost haproxy[671]: 192.168.21.72:56356 [17/Jun/2024:17:35:23.325] fe_ex2019~ be_ex2019_mapi/exch01 0/0/0/39/40 200 1139 - - ---- 47/47/39/39/0 0/0 "POST /mapi/nspi/?MailboxId=4ce22e83-ca6b-47d0-9f69-02dc1024ef02@mydomain1.com HTTP/1.1"
Jun 17 17:35:23 localhost haproxy[671]: 192.168.21.72:56350 [17/Jun/2024:17:35:23.355] fe_ex2019~ be_ex2019_mapi/exch01 0/0/0/31/32 200 1140 - - ---- 48/48/39/39/0 0/0 "POST /mapi/nspi/?MailboxId=9e62a900-a795-4204-972f-6d0ee1cdc563@mydomain2.com HTTP/1.1"
Jun 17 17:35:23 localhost haproxy[671]: 192.168.21.72:56353 [17/Jun/2024:17:35:23.367] fe_ex2019~ be_ex2019_mapi/exch01 0/0/0/33/33 200 1139 - - ---- 48/48/38/38/0 0/0 "POST /mapi/nspi/?MailboxId=9e62a900-a795-4204-972f-6d0ee1cdc563@mydomain2.com HTTP/1.1"
Jun 17 17:35:23 localhost haproxy[671]: 192.168.21.72:56350 [17/Jun/2024:17:35:23.355] fe_ex2019~ be_ex2019_mapi/exch01 0/0/0/31/32 200 1140 - - ---- 48/48/39/39/0 0/0 "POST /mapi/nspi/?MailboxId=9e62a900-a795-4204-972f-6d0ee1cdc563@mydomain2.com HTTP/1.1"
Jun 17 17:35:23 localhost haproxy[671]: 192.168.21.72:56353 [17/Jun/2024:17:35:23.367] fe_ex2019~ be_ex2019_mapi/exch01 0/0/0/33/33 200 1139 - - ---- 48/48/38/38/0 0/0 "POST /mapi/nspi/?MailboxId=9e62a900-a795-4204-972f-6d0ee1cdc563@mydomain2.com HTTP/1.1"
Jun 17 17:36:07 localhost haproxy[671]: 192.168.21.72:55287 [17/Jun/2024:17:15:08.795] fe_ex2019~ be_ex2019_mapi/exch01 0/0/0/36/1259090 200 1679 - - ---- 44/44/36/36/0 0/0 "POST /mapi/emsmdb/?MailboxId=4ce22e83-ca6b-47d0-9f69-02dc1024ef02@mydomain1.com HTTP/1.1"
Jun 17 17:36:07 localhost haproxy[671]: 192.168.21.72:55791 [17/Jun/2024:17:26:08.827] fe_ex2019~ be_ex2019_mapi/exch01 0/0/0/17/599058 200 1354 - - ---- 44/44/34/34/0 0/0 "POST /mapi/emsmdb/?MailboxId=4983ec4f-5055-4ee4-b075-99d505efe435@mydomain2.com HTTP/1.1"
Jun 17 17:36:07 localhost haproxy[671]: 192.168.21.72:55933 [17/Jun/2024:17:30:08.880] fe_ex2019~ be_ex2019_mapi/exch01 0/0/0/15/359005 200 1227 - - ---- 44/44/32/32/0 0/0 "POST /mapi/emsmdb/?MailboxId=9e62a900-a795-4204-972f-6d0ee1cdc563@mydomain2.com HTTP/1.1"
Jun 17 17:36:08 localhost haproxy[671]: 192.168.21.72:56380 [17/Jun/2024:17:36:08.938] fe_ex2019~ be_ex2019_mapi/exch01 0/0/3/9/12 401 514 - - ---- 43/43/36/36/0 0/0 "POST /mapi/emsmdb/?MailboxId=9e62a900-a795-4204-972f-6d0ee1cdc563@mydomain2.com HTTP/1.1"
Jun 17 17:36:08 localhost haproxy[671]: 192.168.21.72:56379 [17/Jun/2024:17:36:08.938] fe_ex2019~ be_ex2019_mapi/exch01 0/0/3/10/13 401 514 - - ---- 43/43/35/35/0 0/0 "POST /mapi/emsmdb/?MailboxId=4ce22e83-ca6b-47d0-9f69-02dc1024ef02@mydomain1.com HTTP/1.1"
Jun 17 17:36:08 localhost haproxy[671]: 192.168.21.72:56378 [17/Jun/2024:17:36:08.938] fe_ex2019~ be_ex2019_mapi/exch01 0/0/3/10/13 401 514 - - ---- 43/43/34/34/0 0/0 "POST /mapi/emsmdb/?MailboxId=4983ec4f-5055-4ee4-b075-99d505efe435@mydomain2.com HTTP/1.1"
Jun 17 17:37:04 localhost haproxy[671]: 192.168.21.72:56483 [17/Jun/2024:17:37:04.400] fe_ex2019~ be_ex2019_default/exch01 0/0/2/1/3 302 255 - - ---- 46/46/0/0/0 0/0 "GET / HTTP/1.1"
Jun 17 17:37:04 localhost haproxy[671]: 192.168.21.72:56483 [17/Jun/2024:17:37:04.407] fe_ex2019~ be_ex2019_owa/exch01 0/0/1/12/13 302 570 - - --NI 46/46/0/0/0 0/0 "GET /owa/ HTTP/1.1"
Jun 17 17:37:04 localhost haproxy[671]: 192.168.21.72:56483 [17/Jun/2024:17:37:04.424] fe_ex2019~ be_ex2019_owa/exch01 0/0/0/11/11 200 29349 - - --NI 46/46/0/0/0 0/0 "GET /owa/auth/logon.aspx?url=https%3a%2f%2fmymailserver.com%2fowa%2f&reason=0 HTTP/1.1"
Jun 17 17:37:04 localhost haproxy[671]: 192.168.21.72:56483 [17/Jun/2024:17:37:04.496] fe_ex2019~ be_ex2019_owa/exch01 0/0/0/14/14 200 61294 - - --NI 46/46/0/0/0 0/0 "GET /owa/auth/logon.aspx?replaceCurrent=1&url=https%3a%2f%2fmymailserver.com%2fowa%2f HTTP/1.1"
Jun 17 17:37:04 localhost haproxy[671]: 192.168.21.72:56483 [17/Jun/2024:17:37:04.612] fe_ex2019~ be_ex2019_owa/exch01 0/0/0/11/11 200 57089 - - --NI 46/46/0/0/0 0/0 "GET /owa/auth/15.2.986/themes/resources/segoeui-regular.ttf HTTP/1.1"
Jun 17 17:37:04 localhost haproxy[671]: 192.168.21.72:56483 [17/Jun/2024:17:37:04.652] fe_ex2019~ be_ex2019_owa/exch01 0/0/0/11/11 200 8201 - - --NI 46/46/0/0/0 0/0 "GET /owa/auth/15.2.986/themes/resources/favicon.ico HTTP/1.1"
Jun 17 17:37:42 localhost haproxy[671]: 192.168.21.72:56498 [17/Jun/2024:17:37:42.377] fe_ex2019~ be_ex2019_mapi/exch01 0/0/1/10/11 401 514 - - ---- 45/45/38/38/0 0/0 "POST /mapi/nspi/?MailboxId=4ce22e83-ca6b-47d0-9f69-02dc1024ef02@mydomain1.com HTTP/1.1"
Jun 17 17:37:42 localhost haproxy[671]: 192.168.21.72:56498 [17/Jun/2024:17:37:42.390] fe_ex2019~ be_ex2019_mapi/exch01 0/0/0/31/31 200 1140 - - ---- 45/45/38/38/0 0/0 "POST /mapi/nspi/?MailboxId=4ce22e83-ca6b-47d0-9f69-02dc1024ef02@mydomain1.com HTTP/1.1"

Does that mean anything?
Or could you please tell me how can i receive more informational logs?

This time the [ERR_CONNECTION_REFUSED] appears in Chrome when i tried to open OWA. And i opened Edge alongside and there are no problems on OWA page. WTH?

6

I noticed in logs that each connection starts with 401 response, if it may be a problem?
/mapi/nspi/?MailboxId=5c5de78e-6f85-4217-808f-3b61c3d4337e@mydomain1.com HTTP/1.1"
Jun 24 09:25:20 localhost haproxy[680]: 192.168.21.53:53008 [24/Jun/2024:09:25:20.656] fe_ex2019~ be_ex2019_mapi/exch01 0/0/0/37/37 200 1232 - - ---- 40/40/29/29/0 0/0 “POST /mapi/nspi/?MailboxId=5c5de78e-6f85-4217-808f-3b61c3d4337e@mydomain1.com HTTP/1.1”

7

Finally got it. My misconfig. I have setuped 2 DNS servers one internal and one external. When i deleted external DNS, everything got ok.