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Richard
2018-08-27T11:28:55Z

> Date: Sunday, August 26, 2018 22:37:55 -0400
> From: TE Dukes <tdukes at palmettoshopper.com>
>
>> From: CentOS [mailto:centos-bounces at centos.org] On Behalf Of
>> Richard Sent: Sunday, August 26, 2018 10:25 PM
>>
>>
>> > Date: Sunday, August 26, 2018 21:10:48 -0400
>> > From: TE Dukes <tdukes at palmettoshopper.com>
>> >
>> >> From: CentOS [mailto:centos-bounces at centos.org] On Behalf
Of
>> >> Richard Sent: Sunday, August 26, 2018 8:31 PM
>> >>
>> >> > Date: Sunday, August 26, 2018 16:25:14 -0400
>> >> > From: TE Dukes <tdukes at palmettoshopper.com>
>> >> >
>> >> >> From: CentOS [mailto:centos-bounces at centos.org] On
Behalf Of
>> >> >> Alexander Dalloz
>> >> >> Sent: Sunday, August 26, 2018 3:46 PM
>> >> >>
>> >> >> Am 26.08.2018 um 20:48 schrieb TE Dukes:
>> >> >> >> You see a basic error message "Could
not connect to
>> >> >> >> localhost:143". So test that without
using additional
>> >> >> >> software. Foremost consult the maillog, in
this case the
>> >> >> >> log content produced by dovecot. And test
connectivity on
>> >> >> >> the lowest level.
>> >> >> >>

>> >> >>
>> >> >> So port 143 is listening. Are we back to the point
that your
>> >> >> DNS or NSS is broken so that even
>> >> >
>> >> > I think so. Everything else work, I don't get it.
>> >> >>
>> >> >> telnet localhost 143
>> >> >>
>> >> >> fails while
>> >> >>
>> >> >> telnet 127.0.0.1 143
>> >> >>
>> >> >> is successful?
>> >> >>
>> >> >
>> >> > Yes, that is correct localhost fails but 127.0.0.1
responds.
>> >> >
>> >>
>> >> In your pastebin:
>> >>
>> >>
<https://paste.fedoraproject.org/paste/MMNEJmqIrEzK-A4N3MR0ZA>
>> >>
>> >> you show three nameservers:
>> >>
>> >>   nameserver 166.102.165.13
>> >>   nameserver 207.91.5.20
>> >>   nameserver 127.0.0.1
>> >>
>> >
>> > The first two nameservers belong to my ISP. Should I move
>> > 127.0.0.1 to the top?
>> >
>> >
>> >> I can't tell if that's what you still have in place,
but note
>> >> that your dns queries will query those DNS servers in that
>> >> order. Based on that order, the "localhost"
(127.0.0.1) server
>> >> is the last one that will be queried. Unless explicitly
queried
>> >> (e.g., with an @<nameserver> syntax) it will only be
queried if
>> >> the other two fail.
>> >>
>> >> Could you confirm the current order (and perhaps list) the
>> >> nameservers in your /etc/resolv.conf file - so we are aware of
>> >> any changes.
>> >
>> > They are still in that order.
>> >
>> >>
>> >> I did a "localhost" query against the first two and
they respond
>> >> correctly, e.g.,
>> >>
>> >>   ;; QUESTION SECTION:
>> >>   ;localhost.			IN	A
>> >>
>> >>   ;; ANSWER SECTION:
>> >>   localhost.		86400	IN	A	127.0.0.1
>> >>
>> >>   ;; Query time: 100 msec
>> >>   ;; SERVER: 166.102.165.13#53(166.102.165.13)
>> >>
>> >> Somewhat related to the:
>> >>
>> >>   > telnet localhost 143
>> >>   >
>> >>   > fails [while it works when you try 127.0.0.1]
>> >>
>> >
>> > Not sure what I have done, but telnet localhost 143 now works but
>> > telnet 127.0.0.1 143 fails.
>> >
>> >

>> >>
>> > 127.0.0.1	localhost localhost.localdomain localhost4
>> > localhost4.localdomain4
>> ># 127.0.0.1     localhost.localdomain localhost
>> > 192.168.1.110	ts130.palmettodomains.com	ts130
>> > 192.168.1.110 mail.palmettodomains.com mail
>> >
>> > ::1         localhost localhost.localdomain localhost6
>> > localhost6.localdomain6
>> ># ::1       localhost6.localdomain6 localhost6
>> > 192.168.1.102	edukes1.palmettodomains.com edukes1
>> > 192.168.1.105	hp8200.palmettodomains.com hp8200
>> > ::1	localhost localhost.localdomain localhost6
>> > localhost6.localdomain6
>> >
>> > -rw-r--r--    1 root     root        509 Aug 26 14:02 hosts
>>
>> Since your:
>>
>>    dig @localhost localhost
>>
>> failed, try:
>>
>>    dig @127.0.0.1 localhost a
>>
>> (in this context, i like the longer output as it reveals more).
>
> From dig @127.0.0.1 localhost a
>
>
> ; <<>> DiG 9.9.4-RedHat-9.9.4-61.el7 <<>>
@127.0.0.1 localhost a
> ; (1 server found)
> ;; global options: +cmd
> ;; Got answer:
> ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 36452
> ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1,
> ADDITIONAL: 2
>
> ;; OPT PSEUDOSECTION:
> ; EDNS: version: 0, flags:; udp: 4096
> ;; QUESTION SECTION:
> ;localhost.			IN	A
>
> ;; ANSWER SECTION:
> localhost.		86400	IN	A	127.0.0.1
>
> ;; AUTHORITY SECTION:
> localhost.		86400	IN	NS	localhost.
>
> ;; ADDITIONAL SECTION:
> localhost.		86400	IN	AAAA	::1
>
> ;; Query time: 0 msec
> ;; SERVER: 127.0.0.1#53(127.0.0.1)
> ;; WHEN: Sun Aug 26 22:29:21 EDT 2018
> ;; MSG SIZE  rcvd: 96
>
>>
>> If that fails, then there is, at minimum, a problem with your local
>> dns server. If that works, try:
>>
>>    dig @localhost4 localhost a
>
> From dig @localhost4 localhost a
>
> ; <<>> DiG 9.9.4-RedHat-9.9.4-61.el7 <<>>
@localhost4 localhost a
> ; (1 server found)
> ;; global options: +cmd
> ;; Got answer:
> ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 39351
> ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1,
> ADDITIONAL: 2
>
> ;; OPT PSEUDOSECTION:
> ; EDNS: version: 0, flags:; udp: 4096
> ;; QUESTION SECTION:
> ;localhost.			IN	A
>
> ;; ANSWER SECTION:
> localhost.		86400	IN	A	127.0.0.1
>
> ;; AUTHORITY SECTION:
> localhost.		86400	IN	NS	localhost.
>
> ;; ADDITIONAL SECTION:
> localhost.		86400	IN	AAAA	::1
>
> ;; Query time: 0 msec
> ;; SERVER: 127.0.0.1#53(127.0.0.1)
> ;; WHEN: Sun Aug 26 22:30:35 EDT 2018
> ;; MSG SIZE  rcvd: 96
>
>>
>> This will explicitly use the ipv4 127. entry in your /etc/hosts,
>> while "localhost" could use either.
>>

Since the localhost4 approach worked, commend out the ipv6 localhost
entries in your /etc/hosts file, then try:

    dig @localhost localhost a

again. If that works try:

    telnet localhost 143

once again. If those work, it would seem that your ipv6 is messed up
and your system is trying it first and not falling back to ipv4.

Regarding your nameserver list in /etc/resolv.conf. If you have a
working 127.0.0.1 nameserver you generally don't include external
nameservers in that list. So, if non-ipv6 things seem to work, I'd
remove the two non-127 nameservers from that list.