# Getting SERVFAILs after upgrade on Raspian 10
**URL:** https://discourse.pi-hole.net/t/getting-servfails-after-upgrade-on-raspian-10/75279
**Category:** Help
**Created:** [January 21, 2025, 9:01pm UTC](https://discourse.pi-hole.net/t/getting-servfails-after-upgrade-on-raspian-10/75279 "2025-01-21T21:01:47Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@bkd84wktgc0k](https://discourse.pi-hole.net/u/bkd84wktgc0k)
#### Post date: [January 21, 2025, 9:01pm UTC](https://discourse.pi-hole.net/t/getting-servfails-after-upgrade-on-raspian-10/75279/1 "2025-01-21T21:01:47Z")
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## Expected Behaviour:
-hardware: Raspberry Pi Model B 2012
-OS: Raspian 10 (Buster)
-Pi-Hole: v5.18.4
-FTL: v5.25.2
-Web interface: v5.21
Today, I attempted to run `pihole -up` and received the message that Buster was no longer supported, so I ran
```auto
sudo PIHOLE_SKIP_OS_CHECK=true pihole -r
```
I chose the repair option, and the install appeared to be successful.
I would expect Pi-Hole to continue running as before.
## Actual Behaviour:
I am now getting SERVFAILs on random domains.
A workaround I found is when I change my upstream DNS server to for example Quad9, DNS resolution starts working again. Previously, my upstream DNS server was a DNS server provided behind the VPN I pay for along with its public IP as a backup.
When I try to change DNS settings from the web interface, I now get the message
```auto
There was a problem applying your settings.
Debugging information:
PHP error (2): fsockopen(): unable to connect to 127.0.0.1:4711 (Connection refused) in /var/www/html/admin/scripts/pi-hole/php/FTL.php:47
```
and FTL stops for about 10-15 seconds before restarting. Not sure if this is related.
## Debug Token:
[https://tricorder.pi-hole.net/mQppsUgU/](https://tricorder.pi-hole.net/mQppsUgU/)
---
### Author:  [@system](https://discourse.pi-hole.net/u/system)
#### Post date: [February 11, 2025, 9:01pm UTC](https://discourse.pi-hole.net/t/getting-servfails-after-upgrade-on-raspian-10/75279/2 "2025-02-11T21:01:55Z")
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