MX Linux networking problem

[DukeComposed]

MX works like all the rest of the linux distro's in how it does dhcp. And that the pinning the ip with his Mac SHOULD work just like all the rest. This method is exactly how I run many networks - letting the router be the brain on "static" ips.

When I first started using alternative operating systems back in college, my FreeBSD CD-ROM didn't come with a DHCP client. I still don't know why. My Windows install, however, did.

This meant that in order to get my machine on the network I first had to boot my machine into Windows, write down the DHCP network config it was assigned, shut the machine down, replace the hard disk in the box with my FreeBSD setup, and use the same IP address and config as a static IP just so I could download a DHCP client for it.

I think it's pretty common these days for home users to define DHCP reservations on their home equipment, and for most devices to come with DHCP clients enabled by default prepared to use them. This is not strictly what network administrators would call "static IP configuration" -- a DHCP server is still involved and the D stands for "dynamic", but the reservations ensure a consistent IP configuration for each device, permanently. If you're particularly annoyed by IPs changing and don't want to touch reservations, you can usually increase the lease validity period on the DHCP server as well.

That way if you take your laptop with you on vacation and come back, say, a week later, the DHCP server will still have the old lease cached... provided you've set the lease duration to 8 days or more. Just make sure your DHCP leases last slightly longer than your longest vacation.

In short, *should work just like all the rest* is an understatement. MX Linux and Mint don't futz with hardware MAC addresses unless you tell them to do so. I'm still not entirely clear on why a dual-boot system would get a different IP address if it's using the same interface on the same network -- it's a fundamental principle of networking that you can reuse the same IP address on the same network card whether you've put the Windows hard drive in it or the FreeBSD hard drive, but the short version is that this is a network issue, not an MX issue.

[CharlesV]

I agree. For YEARS I resisted using the router to pin an IP.. and just set things to a true static ip. However, after YEARS of having issues with people traveling and that static ip bringing my calls from hotels, family homes etc.. I started keying in on the "pin the ip" concept as a better approach to 'static' ip.

I dont dual boot - ever. I find it extremely problematic. However, in testing one of my latest HP laptops I kept windows on board to provide me with easier bios firmware updates - and found that indeed MY pfSense router did keep my same ip when I switched from linux to windows.

Specifically in this topic, the OP stated his IP had changed - although pinned and was working in mint etc... I find it very odd that a router would change the pinned ip... thinking that the MAC "somehow" changed. ( Years of cisco, pfSense and other router programmed have led me to believe that some techs will infact change leases, cache clearing and other nefarious "normal" things to "clean up networking" too! ) And frankly some of the garbage routers / firewalls and other "nest type" systems out there currently I see sporadic norms on just about everything - so not sure 'normal' is even a given these days!

I also find it very odd that an OS would change an ip / mac around, however some OS's do this - Ubuntu and puppy linux both did this to me on installs - my MAC addy on the same machine moved all over the place causing my router to lock it out!

[DukeComposed]

Specifically in this topic, the OP stated his IP had changed - although pinned and was working in mint etc... I find it very odd that a router would change the pinned ip...

I also find it very odd that an OS would change an ip / mac around, however some OS's do this - Ubuntu and puppy linux both did this to me on installs - my MAC addy on the same machine moved all over the place causing my router to lock it out!

There's what could happen, what should happen, and what did happen. And in networking, the Venn diagram of these three circles have very different diameters. It's easy for me to say "DHCP should behave like this, you must be crazy", but truth is we don't know anything about OP's network setup. It might be a bug in OP's router's in-house DHCP server, or a poorly-timed reboot between power-off and power-on that led to a new DHCP lease. If the MAC address was reserved/pinned on the DHCP server, there's no chance MX Linux is going to change that. MAC addresses are assigned by the manufacturer and cannot be changed without some hackery. This is why I mentioned macchanger, which OP almost certainly isn't using and is obligated to mention if the opposite is true. Network tomfoolery tools like that fit into the category of "if you know enough to install and use them, you know enough to turn them off when troubleshooting a real problem". I can trick the coffeeshop's wifi into thinking my MAC address is different for any number of reasons, but on a home network there's no good reason to engage in subterfuge.

OP has some network investigation to do, that much is certain. It's not that something is wrong, per se, because in network administration there are only two states: "broken" and "less broken". We can confidently say from our armchairs that MX didn't cause the breaking this time. A "proper" setup is going involve a DHCP reservation and maybe some split-horizon DNS entries so that "ssh mylinuxbox.internal" always resolves correctly and connects as intended.

This is not a wild and crazy one-off. Getting networking connectivity right is hard. Like really, really hard. It's one of the reason why things like mesh VPNs were invented. Installing and relying on a third-party solution like Tailscale solves a lot of these kinds of issues, but let's take a second to appreciate that even though Tailscale's "always connect my machines point-to-point anywhere in the world" approach would work when both devices are on the same LAN, that's not the intended purpose of the technology.

[CharlesV]

@DukeComposed Very good sir!

[jj 5117]

"...the Venn diagram of these three circles have very different diameters."

Spock says, "It's not the length of the radii that that matters. It's the content of the categories."

[atomick]

DHCP Handshake; https://medium.com/@sajerestan/demystif ... 2f0c553a53

might provide a more accurate understanding of this more "Simple Protocol Handshake" at a time back long ago another galaxy and other hats worn. Protocols used to be a specialty. Ascii / Ebcdic / X.25 / SDLC / ISDN / etc.

the old addy " don't use it you lose it " some is there bootp boots ports 67 and 68 are the 2 working the UDP:port handshake - read the web site and its simple explanation.

example:

Code: Select all

 --OutPut: netstat -tulanp:---  <<< this is my script cmdline syntax to get the below output. 

Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name    
tcp        0      0 127.0.0.1:631           0.0.0.0:*               LISTEN      91728/cupsd         
tcp        0      0 0.0.0.0:47070           0.0.0.0:*               LISTEN      3549/sshd: /usr/sbi 
tcp        1      0 127.0.0.1:52498         127.0.0.1:631           CLOSE_WAIT  3449/cups-browsed   
tcp        1      0 127.0.0.1:22348         127.0.0.1:631           CLOSE_WAIT  3449/cups-browsed   
udp        0      0 192.168.1.188:68      192.168.1.161:67      ESTABLISHED 3599/NetworkManager    

Change of some info slightly .. See or Look at the Last Line start left UDP. my network I modified out of the box to a different Class networking xxx.yyy.xxx.zzz/2x most all are set to /24 which is 255 all out address schema with 1 and 255 isolated not for user access 1 is gateway 255 broadcast. This .255 is where what broadcast multi-plex request uses an DHCP. which "is there anyone out there" your device Mac responds Yes I am powered online and sending syn chars . stop there. rest is Your online who cares about the details. As it seems Tic Tok.