Dovecot not responding
A user reported that she wasn't receiving any email. When I logged into
the mail servers, which runs
Dovecot for POP3/POP3S and used
Telnet to connect to
port 110, the
well-known port for POP3, I didn't get any response after I entered the
user command, so I exited to the telnet prompt with
Ctrl-].
$ telnet 127.0.0.1 110
Trying 127.0.0.1...
Connected to 127.0.0.1.
Escape character is '^]'.
user nell
^]
telnet> quit
Connection closed.
$
I logged into the root account and checked today's and yesterday's
maillog files for any references to Dovecot or POP3 issues, but saw none.
# grep -i dovecot /var/log/maillog
# grep -i dovecot /var/log/maillog.1
# grep -i pop3 /var/log/maillog.1
# grep -i pop3 /var/log/maillog
#
[ More Info ]
[/network/email/dovecot]
permanent link
Viewing the list of IP address ranges for AmazonAWS
If you need to create firewall rules for outgoing connectivity to
Amazon
Web Services (AWS) addresses, you can obtain a complete listing of the
IP address
ranges that
Amazon uses in
JavaScript Object Notation (JSON) format from
AWS IP Ranges Are Now Available in JSON Format - the download URL for the file
is
https://ip-ranges.amazonaws.com/ip-ranges.json
I downloaded the IP address range file from
https://ip-ranges.amazonaws.com/ip-ranges.json using
cURL, which
is present on Apple
OS X/macOS systems and is available for Linux and many other operating
systems, including Microsoft Windows - see
Releases and Downloads.
$ curl -o ip-ranges.json https://ip-ranges.amazonaws.com/ip-ranges.json
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 99k 100 99k 0 0 191k 0 --:--:-- --:--:-- --:--:-- 191k
$
The following Python script can be used to extract just the
Classless Inter-Domain Routing (CIDR) address blocks, i.e.,
the ip_prefix information from the JSON data stored in
the ip-ranges.json file downloaded from the
Amazon website and display it.
#!/usr/bin/python
import json
data = json.load(open('ip-ranges.json'))
for d in data["prefixes"]:
print d["ip_prefix"][ More Info ]
[/languages/python]
permanent link
