Reverse DNS Gives an Incorrect Hostname For My Server or Client: Difference between revisions
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{{Troubleshooting | {{Troubleshooting Header}} | ||
=Problem= | |||
A reverse lookup of the IP address of your machine (client or server) gives a hostname which is generated by the ISP, and is not the one you want to use: | A reverse lookup of the IP address of your machine (client or server) gives a hostname which is generated by the ISP, and is not the one you want to use: | ||
# host 123.124.125.126 | # host 123.124.125.126 | ||
dyn-126.125.my-isp.com | dyn-126.125.my-isp.com | ||
=Solution= | |||
Configure resolution of that IP address locally on the machine(s) which are getting the incorrect hostname: | Configure resolution of that IP address locally on the machine(s) which are getting the incorrect hostname: | ||
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is searched before name servers. | is searched before name servers. | ||
=Explanation= | |||
In this situation, the Amanda security layer does a reverse-DNS lookup of the other host's IP address, and thus sees incoming connections as from e.g., | In this situation, the Amanda security layer does a reverse-DNS lookup of the other host's IP address, and thus sees incoming connections as from e.g., | ||
Latest revision as of 23:19, 22 May 2007
This article is a part of the Troubleshooting collection.
Problem
A reverse lookup of the IP address of your machine (client or server) gives a hostname which is generated by the ISP, and is not the one you want to use:
# host 123.124.125.126 dyn-126.125.my-isp.com
Solution
Configure resolution of that IP address locally on the machine(s) which are getting the incorrect hostname:
- Define the IP address in the hosts file (/etc/hosts) on the backup client
XXX.XXX.XXX.XXX amanda.mydomain.com
- Change the name lookup order in /etc/nsswitch.conf file to
hosts: files dns
The lookup order, eg. files dns (and/or ldap, nis, ...) so that hosts file is searched before name servers.
Explanation
In this situation, the Amanda security layer does a reverse-DNS lookup of the other host's IP address, and thus sees incoming connections as from e.g.,
[email protected]
instead of the intended
[email protected]
and therefore rejects the connection