New linux client can't find server

client
1

Hello,
I’m looking for any suggestions to get my new linux client to see my urbackup server. I already have other linux/windows clients that are correctly configured and working with this server.

client:
Linux rocky 5.14.0-503.21.1.el9_5.x86_64 #1 SMP PREEMPT_DYNAMIC Wed Jan 8 17:35:30 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux

Server is running in a Promox Debian VM.

Client is at 192.168.1.181
Server is at 192.168.1.90

Looking through some posts, I tried this command to see if the urbackup server pings were being received:
sudo tcpdump -i enp8s0 udp port 35622
tcpdump: verbose output suppressed, use -v[v]… for full protocol decode
listening on enp8s0, link-type EN10MB (Ethernet), snapshot length 262144 bytes
15:26:37.734173 IP 192.168.1.90.35623 > 255.255.255.255.35622: UDP, length 1
15:26:37.734174 IP6 fe80::be24:11ff:fe69:2d8d.35623 > ff12::f894:d:dd00:ef91.35622: UDP, length 1
15:26:37.734175 IP 192.168.1.90.35623 > rocky.35622: UDP, length 1

It looks like that is working correctly.

I also tried this command:
sudo netstat -tulpn | grep LISTEN

I got this output:
tcp 0 0 0.0.0.0:35621 0.0.0.0:* LISTEN 55250/urbackupclien
tcp 0 0 0.0.0.0:35623 0.0.0.0:* LISTEN 55250/urbackupclien
tcp6 0 0 :::35621 :::* LISTEN 55250/urbackupclien
tcp6 0 0 :::35623 :::* LISTEN 55250/urbackupclien

I think that looks good.

When I start the urbackupclientbackend I get this in the /var/log/urbackupclient.log

2025-01-18 14:56:15: SQLite: recovered 24 frames from WAL file /usr/local/var/urbackup/backup_client.db-wal code: 283
2025-01-18 14:56:15: FileSrv: Binding UDP socket at port 35622…
2025-01-18 14:56:15: FileSrv: done.
2025-01-18 14:56:15: FileSrv: Binding ipv6 UDP socket at port 35622…
2025-01-18 14:56:15: FileSrv: done.
2025-01-18 14:56:15: urbackupserver: Server started up successfully!
2025-01-18 14:56:15: Started UrBackupClient Backend…
2025-01-18 14:56:15: FileSrv: Servername: -rocky-
2025-01-18 14:56:15: FileSrv: Server started up successfully
2025-01-18 14:56:15: FileSrv: UDP Thread started
2025-01-18 14:56:16: Looking for old Sessions… 0 sessions
2025-01-18 14:56:16: Internet mode not enabled
2025-01-18 14:59:16: Internet mode not enabled
2025-01-18 15:26:17: Looking for old Sessions… 0 sessions

Here is the status output:
{
“capability_bits”: 65548,
“finished_processes”: ,
“internet_connected”: false,
“internet_status”: “no_server”,
“last_backup_time”: 0,
“running_processes”: ,
“servers”: ,
“time_since_last_lan_connection”: 14587823
}

I’m not seeing any errors… The client will sit there and never connect. I’ve let it run for an hour without any other updates. This is my first time using Rocky Linux… so I’m not sure if there are firewall settings that need changing. Any suggstions on things to try would be appreciated.

thanks!

2

I forgot to add the urbackup versions:
UrBackup Client Controller v2.5.25.0
UrBackupServer v2.5.33.0

3

Another update.

I saw this in the client logs when doing additional testing today:
2025-01-19 17:32:33: ERROR: Error joining ipv6 multicast group ff12::f894:d:dd00:ef91

Seems like there are a few of posts relating to ipv6 and urbackup. I’ll see if there are any things to try there. If anyone else encountered this and found a solution, it would be great to hear what you tried. I’ve tried disabling ipv6 on the server, no luck. I tried disabling ipv6 on the client… I still get the same error. I’m not sure if I’m disabling correctly (kinda hitting the limits of my networking knowledge).

later, I went to the sever web page and clicked on the “add new client” button. I selected the second option to manually enter the IP/hostname. When I did that and returned to the status page, the client was listed as “online=yes”. But when the server sent the UDP ping, it switched to “online-no”. It never added the client.

4

I was able to fix the ipv6 multicast error by enabling ipv6 using the nmtui app. (I had disabled earlier while testing things out)

This is what I get now when I start the client:

sudo /usr/local/sbin/urbackupclientbackend -v debug
2025-01-19 20:29:20: SQLite: recovered 24 frames from WAL file /usr/local/var/urbackup/backup_client.db-wal code: 283
2025-01-19 20:29:20: FileSrv: Binding UDP socket at port 35622…
2025-01-19 20:29:20: FileSrv: done.
2025-01-19 20:29:20: FileSrv: Binding ipv6 UDP socket at port 35622…
2025-01-19 20:29:20: FileSrv: done.
2025-01-19 20:29:20: urbackupserver: Server started up successfully!
2025-01-19 20:29:20: Started UrBackupClient Backend…
2025-01-19 20:29:20: FileSrv: Servername: -rocky-
2025-01-19 20:29:20: FileSrv: Server started up successfully
2025-01-19 20:29:20: FileSrv: UDP Thread started
2025-01-19 20:29:21: Looking for old Sessions… 0 sessions
2025-01-19 20:29:21: Internet mode not enabled

Still unable to connect. Before, I was able to get Online=yes when manually adding client to urbackup status page. But now, I’ve returned to Online=no. I’m currently unable to get Online=yes to show up.

5

Ok. It looks like it’s connecting to the server now. I was in the middle of trying different things when the log window started printing a long list of server connection text. Like a lot of other posts, it just started working and I’m not sure why. I think the last thing I was playing around with was the firewall settings.

I had used these commands earlier in the day to open up the ports:
sudo firewall-cmd --zone=public --permanent --add-port=35621/tcp
sudo firewall-cmd --zone=public --permanent --add-port=35622/udp
sudo firewall-cmd --zone=public --permanent --add-port=35623/tcp

But the client still couldn’t connect to the server. After trying several other tests, I had read a post about needing to restart the firewall after making changes. So I used this command to restart the firewall:

sudo firewall-cmd --reload

It starting connecting after that. I confirmed by closing/re-opening the ports and testing the connection. So in the end, I think I got it working… and I learned a little more about Rocky Linux firewall setup.