From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:0.9.4+) Gecko/20010914 Description of problem: When attempting to connect by name using telnet 0.17.6x-18 there are very long delays before anything is displayed, including the "Trying {ipaddr}..." message. The destination computer name is in /etc/hosts, and /etc/host.conf states "order hosts,bind", yet it appears that telnet is still trying a DNS lookup, which for the host in question will not work. Attempting to connect by IP address immediately connects. Is telnet ignoring /etc/host.conf for some reason? Version-Release number of selected component (if applicable): 0.17.6x-18 How reproducible: Always Steps to Reproduce: 1. place host name in /etc/hosts - host must not resolve via DNS 2. verify /etc/host.conf contains "order hosts,bind" 3. run "telnet {hostname}" Actual Results: Long delay, eventual connect. Expected Results: Immediate connect.
New info: now I am seeing the delay on "telnet {ipaddr}" - what the heck could cause *that*?
So, any progress on figuring out what the heck is going on here?
Created attachment 40471 [details] Patch to optionally disable DNS lookups
I've noticed the same thing here... (on RH7.1 & 7.2) My "fix" is the attached patch which adds a new argument -N to optionally disable DNS-lookups. And I wouldn't mind at all if this showed up in the next RH telnet package :)
see http://sources.redhat.com/ml/libc-alpha/2000-11/msg00172.html
BTW I'm not talking about localhost here but something that doesn't exist in DNS at all. Also I found out that the kerberos-version of telnet doesn't seem to make a DNS-lookup if it's given an IP instead of a hostname.
Er, apparently nobody there has twigged to this yet: http://sources.redhat.com/ml/libc-alpha/2001-11/msg00125.html I only got wind of this a couple of days ago, and thought it'd be known to the telnet maintainers, so I didn't post anything. The bug is that telnet is now trying IPv6 lookups even though an IPv4 hostname is in the local hosts file. If there is an IPv4 entry in /etc/hosts for the system name, an IPv6 DNS lookup SHOULD NOT occur. Okay, now that we know what is happening - when can we expect a fix? :)
It seems telnetd may also be subject to this bug...
The best fix for RHL62 errata (where IPv6 was not supported yet) is to change the reference from PF_UNSPEC to PF_INET. Then getaddrinfo defaults to IPv4 lookups first. (perhaps this should be filed against telnet separately.) Anyway, marking this as a duplicate of a latter report on the same subject. *** This bug has been marked as a duplicate of 57998 ***