Self-service help page
There are cases where things dont works and you need to debug your system. SA course lab instructors will publish a list of QA to help you self-debug your errors.
- Firewall and security groups in ETAIS
iptables -S
iptables -n -L -v --line-numbers
iptables -F
- Warning use with caution will delete all Firewall rules
- DNS
- Pay attention to the details when you end name in zone file with dot
.
and when not. If you don't end a name with.
(dot) bind will autocomplete it with yourORIGIN
. If you end a name in zone file with.
(dot) the address in absolute and no auto-completion will be used. dig @172.17.64.203 www.teacher.est
dig @172.17.64.203 teacher.est MX
dig @172.17.64.203 mail.teacher.est MX
- Pay attention to the details when you end name in zone file with dot
- Postfix (
postconf
)
- Dovecot (
doveconf
)
- Apache configuration
apachectl configtest
- https://info.teacher.est/server-info - Has full configuration of teacher.est Apache available. Good for reference.
- If something still does not work go for the log files. (If needed allow extra logging!)
ETAIS Security Groups overview
{{anchor|DNS-host-errors}}
Common DNS errors in your host machine
In any ooperating system you MUST configure your system to use our System Administration course DNS server 172.17.64.203
. There are many ways to do it and depending of your connection, VPN, WiFi, cable it may differ greatly. Nevertheless you should understand that nslookup
and ping
act very differently when checking if DNS is working.
First you should check if known good host is available. (i.e. www.teacher.est)
nslookup www.teacher.est
ping www.teacher.est
Then check if your machine is available
nslookup www.<yourdomain>.est
ping www.<yourdomain>.est
If nslookup
works, but ping
fails your machine is confused which DNS server to use as nslookup
always queries DNS server, but ping
uses cache and fails if first DNS server is answering
with error. You can tell Windows to refresh DNS server list with.
ipconfig /flushdns
ipconfig /registerdns
If still no luck and you are also using VPN try executing this command in elevated Powershell command prompt
Set-ItemProperty -Path HKLM:\SYSTEM\CurrentControlSet\Services\Dnscache\Parameters\DnsPolicyConfig\OpenVPNDNSRouting -Name GenericDNSServers -Value "172.17.64.203;8.8.8.8"
If all previous attempts fail tell Windows/Linux/iOS manually where <yourdomain>.est is located by adding manual DNS records to C:\Windows\System32\drivers\etc\hosts
or /etc/hosts
file depending of your host to solve your domain name.
192.168.X.Y www.<yourdomain>.est
ETAIS in ERRED state
As ETAIS User Interface is quite loosely connected to OpenStack back-end sometimes state in front-end & back-end would be different that results in ERRED
state of your private cloud. Normally syncronize
will fix it.