I. IIS service conflict leads to
It turns out that because IIS is installed on Windows Server, the IIS service in the system is turned on, and there is a default FTP site in the IIS service. The default port is 21, and the default port in SERV-U is also 21, which happens to be a conflict (you can modify the service port of iis or serv_u).
[Solution] So, I stopped the FTP service in the IIS service (or changed the port of the FTP service in IIS, or changed the default port of Serv-U), and I could use SERV-U normally.
After finishing it, not everything works well. I found that Serv-U still prompts "Domain is offline". Just think about it and you can figure it out. Personally, I think that because the FTP in the IIS service has stopped, the status in the Serv-U domain has not been refreshed or updated. So we just need to change the current status of Serv-U or log out of Serv-U and log in again.
In fact, another important question is registration information. Check whether your Serv-U has been successfully registered.
2. The permission settings are incorrect
If we resume FTP space. The corresponding permissions in SERV-U are set. However, FTP still cannot upload files if it logs in. Check the disk and directory permissions specified by SERV-U. If there is no serv account in the permission account, we can manually add one and set the corresponding read and write permissions.
3. Serv-U domain is automatically offline
It’s strange that the FTP built in a few days later, the Serv-U domain was automatically offline as soon as it was turned on. Refill in the domain IP, and after application, it became normal. However, after restarting, it hangs up, causing the FTP connection to fail.
View Serv-U log:
Wed 29Apr09 07:58:56 - SERVER IS NOT LISTENING ON IP 172.16.88.202: Trying to use non-existent IP address?
This should be the normal situation:
Wed 29Apr09 09:07:24 - FTP Server listening on port number 21, IP 172.16.88.202, 127.0.0.1
Check the event log of Windows and the application-related events:
FTP Server listening on port number 43958, IP 127.0.0.1
SERVER IS NOT LISTENING ON IP 172.16.88.202: Trying to use non-existent IP address?
In the system related event log:
Your computer failed to renew its address from the network for a network card with the network address of 0015600F1E28 (from the DHCP server). The following error occurred:
The signal light timeout has arrived. The computer will continue to try to obtain the address from the Network Address (DHCP) server. Based on this, I think there is a problem with DHCP assigning IP addresses, so the Serv-U domain is automatically offline. So, I changed the Serv-U domain IP address to "use any available IP address".
Based on this, I think there is a problem with DHCP assigning IP addresses, so the Serv-U domain is automatically offline. So, I changed the Serv-U domain IP address to "use any available IP address".
This way, FTP can serve normally if any IP is replaced.
However, what went wrong with DHCP obtaining IP addresses is still not clear.
It turns out that because IIS is installed on Windows Server, the IIS service in the system is turned on, and there is a default FTP site in the IIS service. The default port is 21, and the default port in SERV-U is also 21, which happens to be a conflict (you can modify the service port of iis or serv_u).
[Solution] So, I stopped the FTP service in the IIS service (or changed the port of the FTP service in IIS, or changed the default port of Serv-U), and I could use SERV-U normally.
After finishing it, not everything works well. I found that Serv-U still prompts "Domain is offline". Just think about it and you can figure it out. Personally, I think that because the FTP in the IIS service has stopped, the status in the Serv-U domain has not been refreshed or updated. So we just need to change the current status of Serv-U or log out of Serv-U and log in again.
In fact, another important question is registration information. Check whether your Serv-U has been successfully registered.
2. The permission settings are incorrect
If we resume FTP space. The corresponding permissions in SERV-U are set. However, FTP still cannot upload files if it logs in. Check the disk and directory permissions specified by SERV-U. If there is no serv account in the permission account, we can manually add one and set the corresponding read and write permissions.
3. Serv-U domain is automatically offline
It’s strange that the FTP built in a few days later, the Serv-U domain was automatically offline as soon as it was turned on. Refill in the domain IP, and after application, it became normal. However, after restarting, it hangs up, causing the FTP connection to fail.
View Serv-U log:
Wed 29Apr09 07:58:56 - SERVER IS NOT LISTENING ON IP 172.16.88.202: Trying to use non-existent IP address?
This should be the normal situation:
Wed 29Apr09 09:07:24 - FTP Server listening on port number 21, IP 172.16.88.202, 127.0.0.1
Check the event log of Windows and the application-related events:
FTP Server listening on port number 43958, IP 127.0.0.1
SERVER IS NOT LISTENING ON IP 172.16.88.202: Trying to use non-existent IP address?
In the system related event log:
Your computer failed to renew its address from the network for a network card with the network address of 0015600F1E28 (from the DHCP server). The following error occurred:
The signal light timeout has arrived. The computer will continue to try to obtain the address from the Network Address (DHCP) server. Based on this, I think there is a problem with DHCP assigning IP addresses, so the Serv-U domain is automatically offline. So, I changed the Serv-U domain IP address to "use any available IP address".
Based on this, I think there is a problem with DHCP assigning IP addresses, so the Serv-U domain is automatically offline. So, I changed the Serv-U domain IP address to "use any available IP address".
This way, FTP can serve normally if any IP is replaced.
However, what went wrong with DHCP obtaining IP addresses is still not clear.