Does Kaltura server required inverse (PTR) record for DNS?

Community Forums
1

Hi Jess,

I wonder if you could help. Thank you. Dmitri

nslookup 212.x.x.x
** server can’t find 212.x.x.x .in-addr.arpa.: NXDOMAIN

nslookup my.public.domain.name.com
Address: 212.x.x.x

https://httpd.apache.org/docs/2.4/dns-caveats.html

2

@astrava,

No. So long as the Kaltura endpoint/service URL you inputted durnig the configuration stage is resolvable/reachable from within the Kaltura server and all the machines from which you intend to use the web interfaces [Admin Console and KMC] it should be fine.

3

my.public.domain.name.com
IP Address: 212.x.x.x
On proxy server SSl/TLS

My Kaltura server has different host/domain name
kaltura.local.domain.com
10.10.x.x
and /etc/hosts file
kaltura.local.domain.com 10.10.x.x
my.public.domain.name.com 212.x.x.x

KALTURA_FULL_VIRTUAL_HOST_NAME=my.public.domain.name.com:80
CDN_HOSTmy.public.domain.name.com
SERVICE_URL= public.domain.com:443

  1. RHEL 6.9 Kaltura Server v 9.18 (sphinx batch front) 80
  2. RHEL 6.9 MySQL Server v5.6.26
  3. Apache Proxy SSL 433

I appreciate your time and effort. Thanks. Dmitri

4

Hi Jess,

The Apache project has recommendation to use IP and ServerName. I appreciate your help. Thanks, Dmitri

https://httpd.apache.org/docs/2.4/dns-caveats.html

Issues Regarding DNS and Apache HTTP Server

This page could be summarized with the statement: don’t configure Apache HTTP Server in such a way that it relies on DNS resolution for parsing of the configuration files.

If httpd requires DNS resolution to parse the configuration files then your server may be subject to reliability problems (ie. it might not start up), or denial and theft of service attacks (including virtual hosts able to steal hits from other virtual hosts).

;# This is a misconfiguration example, do not use on your server

ServerAdmin webgirl@example.dom
DocumentRoot “/www/example”

In order for the server to function properly, it absolutely needs to have two pieces of information about each virtual host: the ServerName and at least one IP address that the server will bind and respond to.
The above example does not include the IP address, so httpd must use DNS to find the address of www.example.dom. If for some reason DNS is not available at the time your server is parsing its config file, then this virtual host will not be configured. It won’t be able to respond to any hits to this virtual host.

Suppose that www.example.dom has address 192.0.2.1. Then consider this configuration snippet:

;# This is a misconfiguration example, do not use on your server
<VirtualHost 192.0.2.1>
ServerAdmin webgirl@example.dom
DocumentRoot “/www/example”

This time httpd needs to use reverse DNS to find the ServerName for this virtualhost. If that reverse lookup fails then it will partially disable the virtualhost. If the virtual host is name-based then it will effectively be totally disabled, but if it is IP-based then it will mostly work. However, if httpd should ever have to generate a full URL for the server which includes the server name (such as when a Redirect is issued), then it will fail to generate a valid URL.

Here is a snippet that avoids both of these problems:
<VirtualHost 192.0.2.1>
ServerName www.example.dom
ServerAdmin webgirl@example.dom
DocumentRoot “/www/example”