Kamailio 3.1 problems, calls between subscriber fails among other things - sip

I've installed Kamailio on Ubuntu 10.04 LTS via:
http://www.kamailio.org/dokuwiki/doku.php/packages:debs
Updated /etc/kamailio/kamctlrc with:
SIP_DOMAIN=MY-IP
DBENGINE=MYSQL
I've also installed the kamailio-mysql-modules via apt-get.
Then I've run kamdbctl create and created the MySQL database.
After that I've started Kamailio via kamctl start. Success.
At last I've added two users:
kamctl add 100 PASS1
kamctl add 101 PASS2
Now I should be able to call between the SIP clients with the subscribers, correct?
But when I try nothing happens. I also found out that no matter what I use for username and password on the clients, they WILL register successfully.
What is wrong?

You are using the default configuration for Kamailio, which is very open and insecure. In order to get some NAT support there's a flag in the kamailio.cfg file to turn on NAt support, which means that Kamailio will store the sender's IP address in the registration, not the address in the SIP message.
Good luck. If you have any further questions, I recommend the Kamailio user mailing list, which you can find on http://www.kamailio.org
/O

Related

Issues sending email through Google's SMTP Relay

My Ubuntu based webserver needs to occasionally send emails. My python code is:
withsmtplib.SMTP('smtp-relay.gmail.com', 587, 'mydomain.com') as s:
s.sendmail(fromaddr, toaddr, msg.as_string())
s.quit()
I have
a Google workspace account
am using IP authentication (not SMTP auth)
my staging and production servers added as trusted IPs (staging is
local, production is cloud)
This setup had been working fine for 6+ months.
Two days ago I upgraded Ubuntu from 20LTS to 22LTS and python 3.8 to 3.10. Now the email is working fine on the staging server, but production keeps throwing:
Invalid credentials for relay [...]. The IP\n5.7.1 address you've registered in your G Suite SMTP Relay
service doesn't\n5.7.7 match domain of the account this email is being sent from. If you are\n5.7.1 trying to
relay mail from a domain that isn't registered under your G\n5.7.1 Suite account or has empty envelope-from,
you must configure your\n5.7.1 mail server either to use SMTP AUTH to identify the sending domain or\n5.7.1 to
present one of your domain names in the HELO or EHLO command. For\n5.7.1 more information, please visit
https://support.google.com/a/answer/6140680#invalidcred ...
Any suggestions?
Edit 1:
I fired up my old ubuntu server in the cloud. I added its new IP as trusted on Google. The email worked fine. I can think of only three possibilities
Google somehow recognizes and trusts requests coming from the old
device (even though it now has a different IP)
Linode is somehow not sending the correct IP address from my new
server
Something broke during the Ubuntu upgrade
I find each of the 3 possibilities quite bizarre and unbelievable at this point, but I'll keep researching.
PS: Three factoids that may/may not be relevant:
I upgraded the staging server in place. For production I spun a new
instance, made sure everything else was working fine (except
email) and then transferred IP from the existing instance to new
When I log in to my google admin account to edit trusted IP list, my
IP is the same as staging server. I don't think I have the same
option for production, since it's an Ubuntu server I manage through SSH
I found some comments online (none in official documentation), that
the reverse DNS needs to be setup before Google would relay anything.
I set up the entry about 20 hours ago for production, but still
getting the same error. And for my staging server, I don't have rDNS
and it still sends emails (it's accessible from the internet, but I
don't have a static IP)
PPS:
The sender email is someuser#mydomain.com (not #gmail.com)
The production server is hosted on linode.com
This post comes close
to discussing a similar situation, but that is focused more on
signing in. My setup uses IP authentication, not SMTP auth. Plus it was working fine until Friday (8/12)
It turned out to be a really frustrating issue. My best guess is that Linode's Ubuntu 22.04 repository has issues. We were thinking of migrating to AWS anyway, this gave us a strong impetus.
Anyway, here are some tips from my experience that a future reader might be able to benefit from
When you're using IP authentication for Google's SMTP relay, the updates are fairly quick. I ended up spinning at least 5 instances with 5 different IPs, and each time Google was able to trust my IP within 2-3 seconds (after I updated in workspace console)
Google didn't care about my reverse DNS entries. I had read some comments online that Google wouldn't relay without rDNS, but I didn't face any such problems (at least not any rDNS I was setting. The ISP or the cloud provider have a default entry, that was good enough - if Google was even looking for it). This one was particularly problematic because that information can take hours to propagate, and I kept thinking maybe my code will start to work tomorrow.
The error message I received from Google was pretty uninformative. I contacted Google support to see if they have access to anything more meaningful on the server side. They didn't - it was a waste of time
It was somewhat helpful to run a fake SMTP server to see what my client was sending. I got it from this post. I ran it for a setup that was working and one that wasn't. In my case, the communication received was identical. Though in hindsight maybe I would've seen some differences if I ran it on a remote server.
python -m smtpd -n -d -c DebuggingServer localhost:2500

How to Confirm PostgreSQL on Ubuntu VM is communicating with External Server for Updates

I have an Ubuntu VM installed on a client's VMware system. Recently, the client's IT informed us that his firewall has been detecting consistent potential port scans to our VM's internal IP address (coming from 87.238.57.227). He asked if this was part of a known package update process on our VM.
He sent us a firewall output where we can see several instances of the port scan, but there are also instances of our Ubuntu VM trying to communicate back to the external server on port 37258 (this is dropped by the firewall).
Based on a google lookup, the hostname of the external IP address is "feris.postgresql.org", with the ASN pointing to a European company called Redpill-Linpro. As far as I can tell, they offer IT consulting services, specializing in open source software (like PostgreSQL, which is installed on our VM). I have never heard of them before though and have no idea why our VM would be communicating with them or vice-versa. I'm also not sure if I'm interpreting the IP lookup information correctly: https://ipinfo.io/87.238.57.227
I'm looking for a way to confirm or disprove that this is just our VM pinging for a standard postgres update. If that's the case I'd like to restrict this behaviour. We would prefer to do these types of updates manually and limit the communication outside of the VM to what is strictly necessary for the functionality of our application.
Update
I sent an email to Redpill's abuse account. They responded quickly saying that the server should not be port scanning anyone and if it appears that way, something is wrong.
The server is part of a cluster of machines that serves apt.postgresql.org among other postgres download sites. I don't think we have anything like ansible or puppet installed that would automatically check for updates but I will look into that to make sure. I'm wondering if Ubuntu reaching out to update the MOTD with the number of available packages would explain why our VM is trying to reach out to the external postgres server?
The abuse rep said in any case there should only be outgoing connections from the VM, not incoming. He asked for some additional info so I will keep communicating with him and try to update this post accordingly
My communication with the client's IT dropped off so I did not get a definitive answer on this, but I'll provide some new details:
I reached out to the abuse email for Redpill-Linpro. He got back to me and confirmed the server corresponding to the detected IP address is part of a cluster that hosts postgres download sites, including apt.postgresql.org. He was surprised to learn we had detected a port scan from their server and seems eager to figure out why that is happening.
He asked if the client IT could pass along some necessary info for them to set up tracking on that server. But the client IT never got back to me. I think he was satisfied that it wasn't malicious and stopped pursuing it.
Here's one of the messages the abuse rep sent me that may be relevant:
That does look a lot like the tcp to the apt download server yes. It's
strange that your firewall reports that many incoming connections, but
they could be fallout from some connection tracking that's not
operating as intended. The timing appears to be matching up more or
less perfectly. And there should definitely not be any ping-back
connections from it.
Since you appear to be using the http version of the server (and not https) bringing the data in cleartext, they should be able to just
dump the TCP connection contents and verify exactly what it does. But
I bet they are going to see a number of http requests initiated by the
apt client that is checking for updates.

Is there any IRC Server / Demon with integrated "bouncer"?

I want to offer IRC service to other users on my local network.
I'd like to have persistent logs of all (or at least certain) channels and private messages that can be replayed by the client. The log capacity could be limited. I know this is usually handled by a bouncer.
I want this setup to work locally, even if the server uplink goes down, so I probably want to run my own IRC server.
Are there any IRC servers already support this?
Having a common chat and pastebin on the local network is very useful.
I've been attempting this today. And after some tribulations I have success.
I've been running ircd-hybrid without any problems for a while, but conversation histories, as you know, are not saved.
You could use any bouncer but I'll demonstrate ZNC:
If you're running linux, run...
sudo apt-get install znc
once it's installed, run...
znc --makeconf
This generates a config file. When asked for a port number specify a free port. This is the one you will connect to from your client and should NOT be the same as you IRC daemons port.
Later on you will be asked to specify the server you want to connect to, this should be 127.0.0.1:.
Make sure you firewall allows the new port, and restart ircd:
sudo service <your irc daemon> restart
That's it. Unless you've set it's modes to +i, your bouncer should now be visible on the channels you've asked it to join.
For more info on ZNC:
http://wiki.znc.in/FAQ
Might help to talk to the IRC crew at #ircd-coders on irc.ircd-hybrid.org
and for ZNC people... #znc on chat.freenode.net

Mail not getting send to specific domains

We have a VPS with CentOS combined with DirectAdmin which we use for a Magento shop. This runs fine, except for sending email.
Problem:
It appears that some specific domains won't receive our emails and we get a bounce. If we use any other email sending systems, the mails arrive without problems.
The bounce mail contains the following error:
SMTP error from remote mail server after HELO Company-Shops:
host mx-cluster-b2.one.com [IP ADRESS]: 504 5.5.2 :
Helo command rejected: need fully-qualified hostname
After googling and trying things for a week now, I am a bit lost. I tried checking postfix in CentOS, but this is not installed and I'm not quite sure if this is needed.
Possible issue?
I believe the hostfile in CentOS is setup incorrectly:
127.0.0.1 localhost localhost.localdomain localhost4 ... etc
OUR IP Company-Shops
'Company-Shops' should probably be a domain name, am I right? The same as the rDNS. But I'm afraid if I change this it will kill my site and whatnot. I'm not sure if this entry correlates with the 'company-Shops' helo label in the bounce error.
Some extra info:
- We use the webmail Roundcube from DirectAdmin
- At the moment we run one shop, but this might grow a bit (multiple sites on 1 IP)
- We don't use subdomains
- We've set up a reverse DNS, with the domain
Is there anyone with similiar experiences or with a bit more knowledge about this subject? I appreciate any advice we can get, as we are stuck..
Many thanks.
Yes, that's right: your mail server should identify itself using a fully-qualified domain name when it connects to send mail via SMTP. You don't say what mail server you're running, but since you're using DA, it's probably Exim. If so, you want to edit /etc/exim.conf and set primary_hostname to the FQDN of your server.
This would also be a good time to double-check that reverse DNS is set up properly for your IP address. Many hosts will also reject email from servers on IPs without a valid rDNS record.
I'm not familiar with Magento, but I can't see any way that changing the Exim configuration in this way could impact that program.

Receiving email with Amazon EC2?

I have no trouble sending out email with my EC2 server, but how can I check the email that is sent to me? I have an elastic IP setup and modified reverse DNS records. Do I need to install Postfix to receive email?
Ensure that port 25 is active and open on your server. Install an SMTP service on your instance ...postfix is mighty fine.
Ensure you have also set up some MX records if you want to receive email from the world...
I suppose the first thing to do is testing if you can open a telnet connection to port 25 on your server. Then you know if anything is listening for incoming mail.
If not, then you should probably install postfix as well as test your firewall settings (I seem to recall the EC2 having some sort of firewall setting for which ports to allow in the web interface)
edit: correct port number