On 12/10/2010 08:46 AM, Baird, Josh wrote:

Maybe I am missing something here.. but what does ‘sudo’ have to do with DNS resolution?

From: centos-bounces@centos.org [mailto:centos-bounces@centos.org] On Behalf Of Steve Clark
Sent: Friday, December 10, 2010 7:44 AM
To: CentOS mailing list
Subject: [CentOS] sudo doing DNS lookup

Hi,

I have a confusing problem. I have two centos 5,5 boxes. Both have
sudo.i386 1.7.2p1-9.el5_5 installed

I am using the same sudoers file, but the one on box A keeps trying to do DNS lookups
while the one on box B does not. How do I disable this DNS lookup?

Thanks for any info.

That is a very good question.

But here is part of an strace of
sudo cat /etc/hosts

socket(PF_INET, SOCK_DGRAM, IPPROTO_IP) = 4
connect(4, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("198.6.1.4")}, 28) = 0
fcntl64(4, F_GETFL)                     = 0x2 (flags O_RDWR)
fcntl64(4, F_SETFL, O_RDWR|O_NONBLOCK) = 0
gettimeofday({1291986809, 169934}, NULL) = 0
poll([{fd=4, events=POLLOUT}], 1, 0)    = 1 ([{fd=4, revents=POLLOUT}])
send(4, "\1\231\1\0\0\1\0\0\0\0\0\0\5Z7070\tnetwolves\3com"..., 51, MSG_NOSIGNAL) = 51
poll([{fd=4, events=POLLIN}], 1, 5000) = 1 ([{fd=4, revents=POLLIN}])
ioctl(4, FIONREAD, [113])               = 0
recvfrom(4, "\1\231\201\203\0\1\0\0\0\1\0\0\5Z7070\tnetwolves\3com"..., 1024, 0, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("198.6.1.4")}, [16]) = 113
close(4)

--
Stephen Clark
NetWolves
Sr. Software Engineer III
Phone: 813-579-3200
Fax: 813-882-0209
Email: steve.clark@netwolves.com
http://www.netwolves.com