The Wiert Corner – irregular stream of stuff

Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

  • My badges

  • Twitter Updates

  • My Flickr Stream

  • Pages

  • All categories

  • Enter your email address to subscribe to this blog and receive notifications of new posts by email.

    Join 4,230 other subscribers

Archive for December 5th, 2016

nanog: Forwarding issues related to MACs starting with a 4 or a 6 (Was: [c-nsp] Wierd MPLS/VPLS issue)

Posted by jpluimers on 2016/12/05

Time after time issues pop up related to MAC addresses that start with a4 or a 6.

[WayBacknanog: Forwarding issues related to MACs starting with a 4 or a 6 (Was: [c-nsp] Wierd MPLS/VPLS issue)

The underlying issue has to do with switches interpreting too much information of (un)encrypted traffic and dropping them because they wrongly think it’s plain ethernet traffic they need to handle.

MAC addresses starting with a 4 or 6 have have a common bit pattern (likekly that fails with 12 and 14 as well) that cause failure in certain network equipment that’s hard to trace as there is limited.

[WayBackChristian Vogel – Google+ (Physics, Electronics, Software) explains this way better at [WayBack] When your MAC address starts with 4 or 6, weird things can happen and it’s not always fixable… – Kristian Köhntopp – Google+:

Read the rest of this entry »

Posted in Internet, Network-and-equipment, Power User, routers, VPN | Leave a Comment »

18 Useful Commands to Get Hardware Information on Linux – Linuxslaves

Posted by jpluimers on 2016/12/05

Quick look at commands that can be used to gather hardware information such as cpu, disks, memory, partition, peripherals etc on Linux OS based systems

Source: 18 Useful Commands to Get Hardware Information on Linux – Linuxslaves

Covered commands (the article has no index and the headings in it don’t have an id tag, so I linked them to other relevant URLs if I could find them):

  1. lshw
  2. lscpu
  3. lspci
  4. lsusb
  5. lsblk
  6. fdisk
  7. dmidecode
  8. /proc files
  9. free
  10. lsscsi



Posted in *nix, *nix-tools, Linux, openSuSE, Power User, RedHat, SuSE Linux, Tumbleweed, Ubuntu | 2 Comments »

Apache error 503 when using ProxyPass:

Posted by jpluimers on 2016/12/05

When using ProxyPass (for instance within a Location) in Apache and you get an http error 503 (service unavailable), then usually the page/service to which the proxy directs to is dead.

I had this when shellinabox (forked from the old Google code repo) died on me.

In addition, ensure your ProxyPass statements contain a slash at the end your you will get a http error 502  (bad gateway):

Proxy Error
The proxy server received an invalid response from an upstream server.
The proxy server could not handle the request GET /account/login.
Reason: DNS lookup failure for:
Additionally, a 502 Bad Gateway error was encountered while trying to use an ErrorDocument to handle the request.

<Location /shell>
ProxyPass http://localhost:4200/
Require all granted
<Location />
Require all granted

view raw


hosted with ❤ by GitHub



Posted in *nix, *nix-tools, Apache2, Power User | Leave a Comment »

%d bloggers like this: