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LYNX-DEV dns lookups
From: |
Andy Harper |
Subject: |
LYNX-DEV dns lookups |
Date: |
Mon, 22 Dec 1997 15:10:13 GMT |
I discovered the following problem while using LYNX compiled with the socketshr
library for VMS to access a service provided by the british library:
Despite the name (opac97.bl.uk) resolving to an IP address, lynx fails to
connect with:
"unable to access remote host!"
At first, I thought it was inaccessible but no, I could connect to the port
using telnet. Further investigations showed that the socketshr package was
failing to return a valid hostent structure because the DNS could not reverse
lookup the ip address on a gethostbyname call (note: '..name' NOT '..addr')
Enquiries to the maintainers of the relevant DNS maintained that it was
incorrect behaviour and that they didn't see the need for a reverse DNS lookup
entry.
So, my question to the experts are:
* Is it sensible for a system to not have a reverse DNS entry (IE to map ip
address back to name)? I can't see any security risk posed by having one
but can see a lot of instances (EG mail) where it would be bad news NOT
to have one.
* What should a gethostbyname call do if, having gotten the IP address from
the DNS, it fails to retrieve the real name via a reverse lookup in order
to set the h_name item of the hostent structure?
This is not strictly a lynx question but, as it affects lynx, i thought it
useful to post here for info (and any answers if you have them..)
Thanks for any input.
Regards,
Andy Harper
Kings College London
- LYNX-DEV dns lookups,
Andy Harper <=