Description of problem: If /etc/resolv.conf contains an IPv6 nameserver entry with a space after the IP address, then clients only try to resolve the entry via the localhost, which fails because I don't have a nameserver locally: # cat -e /etc/resolv.conf nameserver 2001:470:20::2 $ # ping6 ipv6.google.com unknown host # strace -e connect ping6 ipv6.google.com connect(4, {sa_family=AF_FILE, path="/var/run/nscd/socket"...}, 110) = -1 ENOENT (No such file or directory) connect(4, {sa_family=AF_FILE, path="/var/run/nscd/socket"...}, 110) = -1 ENOENT (No such file or directory) connect(4, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("0.0.0.0")}, 28) = 0 connect(4, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("0.0.0.0")}, 28) = 0 connect(4, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("0.0.0.0")}, 28) = 0 connect(4, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("0.0.0.0")}, 28) = 0 unknown host # I'd guess the extra white space causes the resolver to treat the entry as a hostname or some other invalid entry. This caused me some confusion until I worked out I had an extra space at the end of the line, because the "dig" and "host" tools were working correctly (they don't use the glibc resolver). Version-Release number of selected component (if applicable): Seen in RHEL5.1 and RHEL5.4 How reproducible: Always Steps to Reproduce: 1. Enter a whitespace after the IPv6 address. 2. Try to ping6 a hostname 3. Actual results: "unknown host" and ping6 returns exit code 2. Expected results: Normal ping output. Additional info:
It's a relatively simple fix to the parsing of the resolv.conf file. I'm putting this in the queue of bugs to evaluate for Red Hat Enterprise Linux 5.9.
This request was evaluated by Red Hat Product Management for inclusion in a Red Hat Enterprise Linux release. Product Management has requested further review of this request by Red Hat Engineering, for potential inclusion in a Red Hat Enterprise Linux release for currently deployed products. This request is not yet committed for inclusion in a release.
Note for QE; we fixed this in RHEL 6 (789189), and there's a TCMS testcase for this bug that we can reuse.
Technical note added. If any revisions are required, please edit the "Technical Notes" field accordingly. All revisions will be proofread by the Engineering Content Services team. New Contents: Same as RHEL 6.3 BZ 789189
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. http://rhn.redhat.com/errata/RHBA-2013-0022.html