Bug 238308

Created attachment 153726 [details]
/etc/sysconfig/sendmail

same result from a different cause is bug 217749.

What does etc/hosts look like?
Are there entries for localhost and localhost.localdomain for IPv4 and IPv6?

partial sanitised /etc/hosts:
# Do not remove the following line, or various programs
# that require network functionality will fail.
127.0.0.1 localhost.localdomain localhost localhost.myweb.com.au

192.168.2.0 network.myweb.com.au network #broadcast address
192.168.2.1 router.myweb.com.au router   #firewall/router/vpn
192.168.2.208 poweredge.myweb.com.au poweredge #dell 
...
$ ping localhost
PING localhost.localdomain (127.0.0.1) 56(84) bytes of data.
64 bytes from localhost.localdomain (127.0.0.1): icmp_seq=1 ttl=64 time=0.329 ms

--- localhost.localdomain ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.329/0.329/0.329/0.000 ms
$ ping localhost.localdomain
PING localhost.localdomain (127.0.0.1) 56(84) bytes of data.
64 bytes from localhost.localdomain (127.0.0.1): icmp_seq=1 ttl=64 time=0.133 ms

There is no IPV6 entries. Disabled as in:
http://fedorasolved.org/network-solutions/disable-ipv6

Have you set a hostname for this machine?
Is this hostname only resolvable by dns?

$ ping poweredge
PING poweredge (192.168.32.208) 56(84) bytes of data.
64 bytes from poweredge (192.168.32.208): icmp_seq=1 ttl=64 time=0.612 ms

$ ping 192.168.32.208
PING 192.168.32.208 (192.168.32.208) 56(84) bytes of data.
64 bytes from 192.168.32.208: icmp_seq=1 ttl=64 time=0.131 ms

$ cat /etc/host.conf 
order hosts,bind

if the /etc/hosts entry for poweredge is commented out, then is it no longer
able to resolve the name.

in system-config-network
dhcp(optional) hostname=poweredge
dns hostname=poweredge
dns search path=z  {i think because some tool required me to enter something,
even though it does not make sense to do so}.

$ cat /etc/resolv.conf
; generated by /sbin/dhclient-script
search z
nameserver 210.23.129.34
nameserver 203.0.178.191

I used s-c-n to remove the search path z, save, and restart the machine. same
delay in sendmail/sm-client startup and in fact the search setting came back.

$ rpm -qf /etc/hosts
file /etc/hosts is not owned by any package
I wanted to reset hosts to default as installed, but it isn't in an rpm.

I repeated f7t4 as fresh install {keeping /home partition}. This sendmail issue
did not occur. I am going to reload fc6, update and upgrade to see how
repeatable the fault is.

Created attachment 154687 [details]
three wireshark pcap traces captured as time 0.00 is sendmail start

Reinstallation of fc6 blanking the / partition. no delay.
Updated to 2007-05-14. problem now occurs.
Changing bug version to fc6.
Captured startup in wireshark, attached.
I can see the cause, dns resolution as expected.

1. dhcp and dns on another fc6 machine
s-c-n dns tab shows poweredge and search poweredge
# cat /etc/resolv.conf
; generated by /sbin/dhclient-script
nameserver 192.168.32.68
search poweredge
  * tries to lookup poweredge.poweredge which does not exist - dns informs
sendmail that "does not exist", but it waits 60 seconds and tries again etc.

2. dhcp and dns on home adsl router
s-c-n dns tab shows poweredge and search z
cat /etc/resolv.conf
; generated by /sbin/dhclient-script
search z
nameserver 210.23.129.34
nameserver 203.0.178.191
  * tries to lookup poweredge.z which does not exist - dns informs sendmail
that "does not exist", but it waits 60 seconds and tries again etc.

3. used system-config-network to uncheck get-hostname-from-dhcp.
s-c-n dns tab shows localhost.localdomain and search z
# cat /etc/resolv.conf
search z
nameserver 210.23.129.34
nameserver 203.0.178.191
  * tries to lookup localhost.localdomain, then localhost.localdomain.z which
do not exist - dns informs sendmail that "does not exist", sendmail accepts
this and sendmail/sm_client start in about 3/4 seconds.

I would say that it possible there is a bug elsewhere that is filtering through
to sendmail. Notice how with (3) unchecked get hostname, a lookup is done for
both:
- hostname =localhost.localdomain
- hostname.searchpath =localhost.localdomain.z
both of which fail, whereas with get hostname from dhcp checked,
only one lookup is made:
- hostname.hostname !!
which fails, but sendmail does not accept it, and tries again 60secs later.

[https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=217749]

Created attachment 154690 [details]
package changes leading up to difficulty with sendmail

I notice that dhcp apps have been modified, I will try to backpedal to an older
ones of these to see if it resolves itself.

Can you please try to temporary disable IPv6 for your system? It could be a
source of your problem.

Does disabling IPv6 help for you?

I missed the earlier ipv6 request. Note that ipv6 was disabled {and is also on
this F7 final install} in modprobe.conf:
install ipv6 /bin/true

# ifconfig
eth0      Link encap:Ethernet  HWaddr 00:C0:9F:28:57:E1  
          inet addr:192.168.32.210  Bcast:192.168.32.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1492  Metric:1
          RX packets:412083 errors:0 dropped:0 overruns:0 frame:0
          TX packets:557957 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100 
          RX bytes:212377848 (202.5 MiB)  TX bytes:569404884 (543.0 MiB)
          Base address:0xecc0 Memory:fe100000-fe120000 

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:12169 errors:0 dropped:0 overruns:0 frame:0
          TX packets:12169 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:32737176 (31.2 MiB)  TX bytes:32737176 (31.2 MiB)

# chkconfig --list sendmail
sendmail        0:off   1:off   2:on    3:on    4:on    5:off   6:off
{starting rl 5}

Since this was rather annoying, I disabled sendmail service. Note that since the
report, the machine has had a fresh CentOS install, and then a fresh F7 install.
The sendmail delay continues - even if started from command prompt:

In /etc/hosts there is no ipv6 localhost entry. The cause seems to be related to
the settings received from my dhcp server {a siemens adsl modem/router}, in that
sendmail tries dns lookup a non-existent host, which eventually times out.

sendmail tries to get the full qualified domain name, which is important for a
MTA. Can you please verify, where this "search z" comes from? 
Can you use poweredge.myweb.com.au instead of poweredge?

This bug entry was in needinfo for some time. Closing due to user inactivity as
"NOT A BUG".