main December 2020

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9 participants
6 discussions

Are VPNs really this complex to install and use?
by Chris Green 14 Jan '21

14 Jan '21

I'm looking at ways of connecting a small Linux system (a Beaglebone Black, but a Raspberry Pi is near enough) on my boat in France which is headless and behind a NAT WiFi (or 3G/4G) server to my home desktop or laptop so I can 'talk' to it. Currently I have ssh reverse tunnels set up by outward connections from the remote Linux system that allow me to ssh into the system. This works OK except that the marina WiFi it uses is a 'captive portal' system where you have to open a web browser and it pops up a login screen where you enter name and password before it connects you to the internet. The connection, once made, stays up for several weeks but when it disconnects for any reason there's no easy way to reconnect automatically, has to be a human being to do it. So, I'm considering getting a 3G/4G USB dongle to connect via the mobile network so I don't have to jump through the marina's WiFi hoops. I can continue to do my reverse ssh tunnel connection but everyone I talk to about this says a VPN is the answer. However I'm having a hard time seeing how to get this installed and working without a huge amount of effort. For example wireguard is supposed to be a simpler, easier alternative to OpenVPN but take a look at:- https://www.wireguard.com/quickstart/ It's horrible! It's do-able, I can understand all the stages but it's just not nice. Similarly VPN tutorials are full of misinformation, take a look at this one:- https://thishosting.rocks/how-to-set-up-openvpn-on-ubuntu/ It's rubbish! ... and all the others I've looked at are either similarly wrong or more complex than the wireguard one. Is VPN *really* this difficult? If so I'll stay with my ssh approach. -- Chris Green

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Unattended remote access - what ways are there to provide it?
by Chris Green 02 Jan '21

02 Jan '21

I have a Beaglebone Black (SBC like a Pi) on my boat in France that I want to be able to connect to using ssh, how can/should I do it? I have a number of possible solutions in mind but I won't give them here as that might prevent open and lateral thinking being applied. Speed is not an issue, a 2400 baud dial up connection would be sufficient. Security is not a big issue, there is no sensitive data on the Beaglebone Black. I guess it needs to be reasonably secure against misuse but thats all. It's inside the boat in a fairly secure marina so the hardware is safe enough. Cost is important, this isn't something I want to spend lots of money on. A solution costing £7/month seemed a bit expensive to me, I'm aiming at significantly less, one or two pounds a month is fine. The boat is moored in an urban environment, power is (fairly) freely available. When I visit the boat I have lots of time to do fairly complicated set-up if needed but once I've left it's totally inaccessible, it has to work totally unattended, there's no one to phone up and ask to 'press the reset' or similar. So, let your imaginations run wild and come up with some ideas! :-) -- Chris Green

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Backuping up gnome desktop settings
by Steve Mynott 31 Dec '20

31 Dec '20

I'm running Ubuntu 20.04 but with a customised desktop setup which is using gnome-session, the ubuntu dock and "move clock" extension (intended to fix the excesses of both Canonical and Gnome). I was quite happily running this on two systems but had to force power off on one because my screen wasn't responsive (screen res mode issues after running an emulator under wine). To my horror this broke many of my customisations, and I was unable to fix them via the Gnome Settings and Tweak Tool. I had to "rm ~/.config/dconf/user" in order to use Tweak Tool successfully which leads me to suspect that this (binary) file became corrupted. First Question: is it usual for this file to become corrupted? I can turn it into a human-readable form by "dconf dump /" it seems. Second Question: How can I regenerate the binary file "~/.config/dconf/user" from a copy of this dump? I don't want to manually do all the config if this happens again, and I'm unimpressed that gnome seems to lose its settings. -- Steve Mynott <steve.mynott(a)gmail.com> cv25519/ECF8B611205B447E091246AF959E3D6197190DD5

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email lunacy
by mick 30 Dec '20

30 Dec '20

Hi and Merry Christmas to all I am having a problem with my email server and would like some advice as to the best way forward. I have run my own SMTP server for about a decade now (beginning at bytemark, but now hosted with Hetzner - which /may/ be the problem). The server (at tap.rlogin.net) runs postfix and dovecot on debian 10 and uses a letsencrypt TLS certificate to transmit mail securely. The server has valid DKIM and SPF records and is not listed on any RBL at mxtoolbox.com. I have no problem sending email to any of the major email providers but recently I have had mail refused by two organisations. One is a small company which uses mimecast filters, the other is ntlworld.com (who use cloudmark). The rejections I receive are "hard" 550 refusals with messages referring to the respective filter mechanisms. I have, of course, contacted the companies using these filters and neither are interested in doing anything about it - they simply refer me to the respective filter providers. Here I enter the catch 22 world of email delivery in that I cannot send email to eiether cloudmark or mimecast - because they use their own products. This is a classic example of why RBLs are a bloody stupid idea, but hey. To make matters worse, the preferred feedback mechanism for both cloudmark and miimecast is via on-line feedback forms. Feedback to cloudmark vanishes into a black hole and I have never had a response from them. Mimecast's is even worse in that it doesn't actually work ("internal server error" would you believe). So I'm a bit stuck. I have resorted to sending email to them from a free GMX account I have, but I should not have to do that (and I still await replies anyway). So - I /believe/ (but have no proof) that the reason my mail server fails a "reputation test" is that it is on a network block used by many others, and which may include Tor servers for example. Certainly I have a Tor node on Hetzner (but on a different network block). It strikes me a simply lazy for any admin to block a whole range of addresses on the grounds that it /may/ contain problematic servers, but hey. admins can be lazy. The reason I am seeking advice here is that some of you also run email servers (or may have dome so in the past). Ideally I would like to continue to run my own server. I like the control and flexibility it gives me. But it is becoming increasingly difficult to do so in the face of the kind of opposition I see. I see only two options. 1. I find a new VPS provider which can guarantee that its network will not be blocked by lazy idiots and I move to them. or 2. I give up and move my email to a third party provider (such as Ionos) I am reluuctant to do 2 because apart from the loss of control, I would have to pay for each and every email address I use, and there are several, spread across (currently) four separate domains, there are often limits on the size of the emailboxes, or number of emails you can send, and there are also often limits even on the number of /aliases/ you can have. My current Hetzner server costs me less that three euros a month. I'd be willing to pay more (Bytemark used to cost me £12.00 a month) if I could be sure that I woudn't have to move again. Does anyone have a recommendation for a good VPS provider that would meet my requirements? If not, does anyone have a recommendation for a third party email provider that can accomodate multiple domains and email addresses without charging stupid amounts? Any and all advice gladly accepted. Best for the New Year Mick --------------------------------------------------------------------- Mick Morgan gpg fingerprint: FC23 3338 F664 5E66 876B 72C0 0A1F E60B 5BAD D312 https://baldric.net/about-trivia ---------------------------------------------------------------------

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Re: [ALUG] email lunacy
by Phil Ashby 25 Dec '20

25 Dec '20

On 24 Dec 2020 14:34:25 mick <mbm(a)rlogin.net> wrote: > Subject: [ALUG] email lunacy > ... > Does anyone have a recommendation > for a good VPS provider that would meet my requirements? If not, does > anyone have a recommendation for a third party email provider that > can accomodate multiple domains and email addresses without charging > stupid amounts? I operate a very similar setup (albeit with Exim not Postfix =), and have done so almost without incident for 20ish years. For the last 5 years I have hosted in Azure on a paid account with a fixed IP, who seem to be rather more trusted than the cheapest providers such as Hetzner. Prior to that I was sharing a physical machine hosted by Atomwide (small org), and I'm planning to switch back to an arrangement as described by Chris Green, hosting at home and using my ISP's relay, now that I have sufficient bandwidth locally (this was the only reason I had an external relay at all). It remains to be seen if they block outgoing mail for the various domains I support... testing TBD! Cheers, Phlash.

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Exim4 filtering
by Jenny Hopkins 20 Dec '20

20 Dec '20

Hello, I'm trying to make a global version of the .forward file for exim4, instead of each user having their own. I want this to send messages flagged as spam straight to that users spam box. To do this, I need to extract the user part of the email address. I've found this helpful line: # echo "john(a)somewhere.com" | cut -d@ -f1 john but can't work out how to put it in a format that exim will like. if $h_to: blah then save /home/$home/Maildir/.spam add 1 to n0 endif That "blah" need to extract the name from the header and set it as $home. Any hints welcome! Thanks, Jenny

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