Intel Xeon PHI?

[Nick]

If you are now asking your router to run a wired LAN and a wireless LAN at the same time, I think you need to agree with it on how it is supposed to do that!
In particular, does it see itself as a switch between the 2 LANs or as a router?
Are you the router sysadmin or is that your Internet sevice provider?

[kriesel]

Originally Posted by ewmayer

Wait - OMFG, just tried posting the above using my Mac, it no longer sees NETGEAR63 anymore, either. Only ~half the usual # of router status LEDs lit. Unplug ethernet, no joy. Unplug/replug router (reset button is microscopic and recessed), wait 5 mins, LEDs green but again only half the usual. Using the downstairs Whole Foods' wifi to post this. Better stop for tonight or I'm gonna risk getting into breaking-stuff-out-of-frustration mode. Replugging the ethernet cable better at least give me something usable.

When I was an apartment dweller, it was common that a cable guy futzing in the wire closet to hook up a new account would hose an existing account's connection (mine). More recently, a township roadside mower hit the roadside fiber connection box and took out connections by the dozens; multiple ISP technicians spent hours at that box reconnecting the neighborhood. Sometimes the issue is upstream and physical damage or ineptness.

[moebius]

Originally Posted by Mark Rose

Turn off WPS, too. WiFi Pathetic Security is susceptible to brute forcing.

I've never used that because I am aware of this additional vulnerability. The stupid thing is that the first 6 digits of the hexadecimal representation of a MAC address are manufacturer-specific, so easy to guess. Still, none of the attackers has ever gotten my ass.

[ewmayer]

Originally Posted by Nick

If you are now asking your router to run a wired LAN and a wireless LAN at the same time, I think you need to agree with it on how it is supposed to do that!
In particular, does it see itself as a switch between the 2 LANs or as a router?
Are you the router sysadmin or is that your Internet sevice provider?

It's a standard-issue Netgear modem router, designed to be compatible with my Comcast cable+internet service - I bought it a few months after moving into my current place, to replace the Comcast router that came when I first started the service, thus a one-time $50 ebay purchase saves me the $10/mo rental fee for the Comcast router. It worked right out of the box, though until last night I only ever used it as a wifi router.

Per the user manual, there is no 'or' re. wifi-vs-ethernet mode, and why would there be? Modern wired households you expect someone - perhaps for their work - might need the full-speed ethernet connection, though most users will be fine with the wifi. But due to the possibility that it might in fact be a one-or-the-other, I first unplugged the ethernet after seeing no wifi signal last night, then - with the ethernet still unplugged - power-cycled the router, in hopes it would come back up with wifi on.

Currently again have the cable plugged in, at least that works, but my various other devices doing GIMPS work are running non-networked, as I have just 1 cable long enough, and don't want to run multiple cables across my living room floor. Per the manual I should have admin access (via uid 'admin' and a pwd on a label inside the box), but never tried it before - the suggested browser access is a no-go because the router wi-fi remains off ... able to ping it via the cable-connected box, but ssh to that IP# via 'ssh -l admin 192.168.0.1' gives 'ssh: connect to host 192.168.0.1 port 22: Connection refused'.

Again, I still don't see why it should be a choice of wifi *or* ethernet.

Back to CentOS-GUI-wrangling over ethernet.

Edit: Found the problem[/url] - cf. the "Cat25 issue" on that page. :) In my case it wasn't a cat issue, but the wifi on/off button is very light-touch in terms of toggling -- when I was moving the router out from behind the sofa and plugging the ethernet cable into the back I must've I must've accidently tripped the wifi into off mode. Whew! back in business. My router only came with quick-start guide, just DLed the complete user manual and noticed another thing, the buttom above wifi on/off is WPS on/off, and its status LED lit to green 'on' as soon as I turned the wifi back on. I always connect via WPA2 and password so I want this one off for security, yes?

[moebius]

Originally Posted by ewmayer

the buttom above wifi on/off is WPS on/off, and its status LED lit to green 'on' as soon as I turned the wifi back on. I always connect via WPA2 and password so I want this one off for security, yes?

yes better it is at off, WPS is even more insecure, is it for fast guest-access and can easy be bruteforced.

[paulunderwood]

I downloaded the big CentOS-8.2.2004-x86_64-dvd1.iso and installed it under qemu. I selected "Workstation" and from the panel on the right "Development Tools". After installation it booted into Gnome, gcc was there and I activated my NIC with nmtui, Job done!

[ewmayer]

Originally Posted by moebius

yes better it is at off, WPS is even more insecure, is it for fast guest-access and can easy be bruteforced.

Alas, pressing - either quickly or hold-for-a-while - that button only resets the WPS, LED blinks for a few seconds and then relights solid green. Ah, well, maybe later will figure out a way to disable via admin-access mode. But not today.

With wifi reestablished checked my connect options on the KNL via nmtui - still won't allow me to activate the wifi, maybe because the LAN is connected?

Anyhow, DLed Gnome onto the KNL, that took around an hour for the nearly 1000 associated packages ... rebooted, said a silent "please don't come back up in cmd-line mode" prayer ... and we have an actual Desktop. Hooray. And lookee here - as soon as I logged into that and clicked through the set initial-prefs screen (e.g. location services? no, thanks) and brought up the settings menu, I saw that it had auto-activated the wifi and was using that ... unplugged LAN cable, yep, we still have internet access. I believe several people asked "why do you even need the GUI desktop?" ... never thought I'd find myself appending "in order to use my !$$@% wifi" to the usual list of answers.

Thanks to all who helped or at least tried to, time to download any remaining packages I need for my development work and maybe finally try building some code.

Originally Posted by paulunderwood

I downloaded the big CentOS-8.2.2004-x86_64-dvd1.iso and installed it under qemu. I selected "Workstation" and from the panel on the right "Development Tools". After installation it booted into Gnome, gcc was there and I activated my NIC with nmtui, Job done!

Yeah, well *now* we know that minimal-install .iso is not the way to go - thanks for rubbing it in, though. :) Again, it would've been nice if the installer UI would clue one in to such stuff, say, by not allowing one to select "server plus gui" and "development tools" without a warning to effect of "these are not included in your boot image, and will need separate install over an internet connection after the basic OS installation".

I see I need to get gcc &c. as well.

[paulunderwood]

Originally Posted by ewmayer

Thanks to all who helped or at least tried to, time to download any remaining packages I need for my development work and maybe finally try building some code.

[ewmayer]

One more Q re. remote access: "hostname -I" gives no fewer than 3 IPs:

192.168.0.89 192.168.0.84 192.168.221.1 [ssh-key stuff]

Tried sshing in from laptop using alternately each of those 3 IPs, got "No route to host" every time. Is there some setting I need to enable in CentOS to allow such remote ssh access?

Edit: A few mins after posting above, notived that my yum-install-packages had stalled ... ping-outside-world also no longer worked. Wifi shows up as connected, but seems to have gotten borked ... plugged LAN back in, resumed download, and now all of sudden 'ssh -l ewmayer 192.168.0.84' (the ...84 is the IP# showing up under wifi-connection details) from the laptop succeeds. Weird ... but now that LAN cable is def. gonna stay plugged into the router behind the sofa, and rolled up ready to pull out under the end table.

[paulunderwood]

Originally Posted by ewmayer

One more Q re. remote access: "hostname -I" gives no fewer than 3 IPs:

192.168.0.89 192.168.0.84 192.168.221.1 [ssh-key stuff]

Tried sshing in from laptop using alternately each of those 3 IPs, got "No route to host" every time. Is there some setting I need to enable in CentOS to allow such remote ssh access?

On the phi box enter ip address. You should be able to ssh its own IP from it.

Although... It looks to me that you have a subnet problem, because 192.168.221.1 is probably masked with 255.255.255.0. I am getting out of my depth here

[ewmayer]

Originally Posted by paulunderwood

On the phi box enter ip address. You should be able to ssh its own IP from it.

Although... It looks to me that you have a subnet problem, because 192.168.221.1 is probably masked with 255.255.255.0. I am getting out of my depth here

See my edit to the above post - transient wifi outage, it seems.

Installed gcc (it grabs 8.3.1) and gdb ... ssh is clearly already working, and python3 also there. One yum no-package-found does concern me, though:

No match for argument: libgmp-dev