Ever wondered if enabled gentoo overlay is used at all on a gentoo machine? To list installed and overlays use the eselect command:

Additional gentoo overlays have a URL listed. The sandbox overlay is a local overlay local overlay, and is not taken into count. The index f.e. like [42] differs between gentoo hosts, this is normal, it is not globally significant. Use the eix to get a overview which software is installed from a overlay:

This is a example output, notice gentoo overlay is left out, it is basically portage:

eix --installed-in-overlay
[I] app-misc/doublecmd-bin [1]
     Available versions:  (~)1.0.1 (~)1.0.2 (~)1.0.4{tbz2} {gtk qt5}
     Installed versions:  1.0.4{tbz2}(18:06:08 02/03/22)(gtk -qt5)
     Homepage:            https://doublecmd.sourceforge.io/
     Description:         Free cross platform open source file manager with two panels side by side.

[I] games-roguelike/cataclysm-dda [2]
     Available versions:  (~)0.9f{tbz2} **9999-r9*l {astyle clang debug lintjson lto ncurses nls pch sdl sound test xdg KERNEL="Darwin linux"}
     Installed versions:  0.9f{tbz2}(22:15:11 02/02/22)(ncurses nls sdl sound -astyle -clang -debug -lintjson -lto -pch -test -xdg KERNEL="linux -Darwin")
     Homepage:            https://cataclysmdda.org
     Description:         Roguelike set in a post-apocalyptic world

[1] "guru" /var/db/repos/guru
[2] "raiagent" /var/db/repos/raiagent

Found 2 matches

In the output above 2 overlays are installed. The GURU overlay and the raiagent overlay are installed and enabled in the example. The result is, no wasted resources at this gentoo node. The sandbox overlay is a local repository,hence the name, sandbox.

dd is a CLI utility to disk dump or to copy a whole physical or logical storage from one to another. It is part of the coreutils package. Coreutils are the standard GNU utilities like (chmod, cp, dd, ls, sort, tr, head, wc, who,...). Using dd needs real caution and triple or even quadro checking before hitting the ENTER button, double check is not enough. Real horror stories arise from quickly using this disk destroyer tool.

dd is runs silently per se and might leave you in a state where one thinks nothing is happening. It is a good idea running dd using the status=progress option to see current progress, like in the example below. The progress is in the second line and will adjust each second regarding the bytes and the used bandwidth:

Think twice, check tripple before using the disk dump utility. Best practice is to use the status=progress option while running it.

Cisco's IOS calls it Administrative Distance, other vendors call it Default Preference, Distance, many vendors call it Priority. But what is this administrative distance?.

Administrative Distance or Priority is a networking operating system specific priority table for the supported routing protocols.

The protocol with the highest priority on this priority table, wins. The highest priority is in that case either 0 or 1 or a the smallest digit. Across all network operating systems in the overview below, the highest priority is always set to the directly connected network it is everywhere 0, or some kind of system or kernel route.

Here following acronyms would describe the following overview also good enough. These are my own ideas how it also could be named or described in short form cross-vendor:

• NOSSDAD - Network Operating System Specific Default Administrative Distance
• IDRPP - Implementation Dependent Routing Protocol Priority

RouterOS

MikroTik's (RouterOS) RouterOS - Route Distance

What is MME? Mesh Made Easy a RouterOS/MikroTik routing protocol based on B.A.T.M.A.N..

ArubaOS

Aruba's (ArubaOS) Administrative distance is found on docs for the 3810 and 5400R series routers. Aruba 3810 / 5400R Multicast and Routing Guide for ArubaOS-Switch 16.08

B.I.R.D.

linux's () - Control Plane for linux IP routing. No official documentation found yet.

* Update *

Interesting note on the default preference behaviour from the mailing list says:

Note though that the preference value in bird is inverted compared to
Cisco which uses administrative distance. Juniper seems to use the term
preference value but have the same semantics as Cisco administrative
distance.

Bird preference value: higher is more preferred
Cisco/Juniper AD value: lower is more preferred

* Last update 2023 *

This is the last update regarding B.I.R.D.

• B.I.R.D does not properly support the same route coming from multiple routing protocols; it's undefined behavior in B.I.R.D.
• B.I.R.D.'s official documentation is lacking ANY examples on how to configure and handle B.I.R.D. with different vendors routing implementations.

If you find out a way how to configure and operate B.I.R.D. with different vendors please write me an email. I have been searching for simple configuration examples on this topic now for a long time. The usersbase could not hint me into the "right" direction. I still do not know how to configure B.I.R.D. and how to operate it in a multi vendor network environement.

IOS/IOS-XE/IOS-XR/NX-OS

Cisco's - Internetwork Operating System (IOS) IOS/-XE/-XR/NX-OS - Administrative Distance

JUNOS

Juniper's (JUNOS) JUNOS - Default Preference

EXOS

ExtermeNetworks's (EXOS)

No online reference found yet. The output is taken from the EXOS cli. EXOS as the only network operating system has a protocol priorty range x > 256. The LOWEST priority is assigned to the *Bootp protocol to 5000. The directly connected network has a priority of 10, this is the highest priority setting.

FRR

linux's Free Range Routing (FRR) FRRouting - Administrative Distance

Comware

HP's (ComWare) ComWare's preference

ComWare has the lowest preference on BGP compared with other implementations.

SR OS

Nokia's - Service Router Operating System (SROS) Route Preference Defaults by Route Type

VRP

Huawei's - Versatile Routing Platform (VRP) Routing Protocol Preference

What is OSPF ASE? Did not find out yet. It might be some Stubby Area perhaps. No online documentation found. Interestingly, VRP has a much lower preference for static routes than any other implementations.

Find the UUID of a local storage device simply by using the ls command, this is the easiest way using agnostic tool:

However, the upper example using the ls command fails to show local storage devices on a ARM7 architectures, here as shown below:

On ARM architecture, specifically on Rapsberry Pi2 which is the upper failed example, finding the UUID works using the lsblk command, which is part of the sys-apps/util-linux called list block devices. The command below shown is using only 4 options to get only the interesting output for the current taks. Options used are: path, type, mountpoint and UUID:

How to find out using NX-OS, which physical port or which SVI makes a lot of traffic, ad-hoc? Right now? At the current moment?

The command presented below is especially useful in that particular case, if there is no access to any SNMP graphs, and no access to any historical data regarding the amount of traffic, and you work f.e work for Cisco's TAC, or you do any network operation oriented work, and your customer says something about "...much bandwidth...where does this traffic come from...". This is using NX-OS, version 8.4(5).

There is this top-talker term, which is often used in addition to netflow, at least in the cisco networking jargon. There might be also other vendors or applications too, using this term in the context of ad-hoc IP bandwidth monitoring or troubleshooting.

Specific top-talker command output with traffic sorted by the amount of send and received traffic and the available interface bandwidth . The full-blown output for the TX/RX side and for the BUM traffic (Broadcast, Unicast, Multicast):

The command and the output shown needs a bit of time until the statistics are visible in the command line. Patience.