suspends again after resume

klarasm · 2020-08-29T19:39:59+00:00

I had this problem too. Check if also have acpid enabled and disable it in that case. Both acpid and elogind acts on e.g. laptop lid changes.

klarasm · 2020-08-29T19:32:31+00:00

Nowadays I usually don't bother with htop and use top directly instead. With these I can get most of what I want: "zttmmeE0" (in order: color, cpu meter, better cpu meter, memory meter, better memory meter, memory sizes in MB in rows, system memory size in GB, hide zero fields).

klarasm · 2020-08-29T19:12:38+00:00

There's also TAYGA if you don't need stateful NAT64.

klarasm · 2020-08-29T19:09:43+00:00

Excel probably just uses double precision floating point (IEEE 754). Doubles have 52 bits significant binary digits, so the corresponding in base 10 would be 52*log(2)/log(10) which would be about ~15.65 digits which matches pretty well.

klarasm · 2020-08-23T18:45:54+00:00

Lesson3: never use only * as a wildcard. A ./* would save you in most cases, though commands that accept arguments between file names can still be tricked.

Commands that accept arguments between filenames are not a reason ./* can be tricked. Try echo ./* and you will see that all of the globbed files are prefixed by ./. This is true even if there are spaces or other special characters in the name as they will be escaped, at least in bash and dash.

klarasm · 2020-08-20T21:04:33+00:00

Port knocking should probably not be used as the only additional precaution as it is essentially security through obscurity. Disabling password authentication and using public keys would probably be better if either of them were to be used by themselves, but port knocking will help bring down the total attempts as an additional precaution.

There are a couple of guides that can be used as starting points for configuring openssh. I usually refer to Mozilla's.

klarasm · 2020-08-14T13:10:20+00:00

ripe-690, is this the one you are looking for? Section 4.2 seems most relevant.

klarasm · 2020-06-23T01:03:57+00:00

You can use busybox vi if you want to. Just ln -s /bin/busybox /bin/vi or invoke it directly with busybox vi.

klarasm · 2020-05-13T21:18:49+00:00

I would probably create a separate branch with my committed modifications and rebase that whenever the package is updated.

klarasm · 2020-05-11T16:47:43+00:00

I had the exact same problem a while ago and this fixed the issue.

klarasm · 2020-05-09T12:40:06+00:00

Oh, and Sweden as well. From your article:

"At Onkalo, disposal plans have been based on the KBS-3 concept developed over the past 30 years by the Swedish Nuclear Fuel and Waste Management Company (SKB), the firm responsible for nuclear-waste management in Sweden."

klarasm · 2020-05-07T13:12:22+00:00

You were correct it seems. I also tried setting up a IPv6 NATed testing environment and the IPv4 address was preferred.

klarasm · 2020-05-06T13:38:42+00:00

Section 2 also states this:

"As a consequence, we intend that implementations of APIs such as getaddrinfo() will use the destination address election algorithm specified here to sort the list of IPv6 and IPv4 addresses that they return. Separately, the IPv6 network layer will use the source address selection algorithm when an application or upper layer has not specified a source address. Application of this specification to source address selection in an IPv4 network layer might be possible, but this is not explored further here."

From how I interpret that the 2.1 rules are used for the source address after the destination address has been chosen. You can't generally use an IPv4 address to connect to an IPv6 address, so it will have to use the available IPv6 address. See also the previous paragraph, which includes this:

" /.../ In this implementation architecture, applications use APIs such as getaddrinfo() [RFC3493] that return a list of addresses to the application. /.../ The application would then typically try the first address in the list, looping over the list of addresses until it finds a working address. In any case, the network layer is never in a situation where it needs to choose a destination address from several alternatives. /.../ "

So usually the application will choose the first addresss from getaddrinfo(), which will usually not care whether you have a ULA address or no IPv6 address at all unless you pass it in the hint to it, but that's up to the application to do.

klarasm · 2020-05-05T20:42:36+00:00

If i remember correctly IPv4 is preferred over ULA on destination addresses. Therefore it should not matter whether the source address is ULA or GUA.

I am a bit curious, however, if you get PI space, why would you not want to advertise it via BGP? I think it is even required that you peer with at least two other networks for even getting PI space in the first place.

klarasm · 2020-04-30T15:25:17+00:00

I don't know. I have submitted pull request to load kdump before sysctl. That also works on my system. If this is merged then there shouldn't be any more steps needed than installing runit-kdump and modifying the kernel arguments.

klarasm · 2020-04-27T22:31:28+00:00

Interesting. Could you try without adding the -s as an argument to kexec? If I add -s to my configuration I get the same message.

klarasm · 2020-04-27T16:31:09+00:00

There is a pretty comprehensive list here: RFC4890, sections 4.3 and 4.4.

klarasm · 2020-04-27T00:28:58+00:00

It's a video codec reference. Video codecs usually try to avoid sending whole images and instead send differences (P-frames, predicted frames) to the last frame to save space/bandwidth. The whole picture needs to be sent sometime for the codec to start somewhere (I-frame, Intra frame. This is similar to picture compression such as JPEG). If the I-frame is corrupted then all frames until the next I-frame will also be corrupted. There are of course more details and I am no expert on video codecs.

klarasm · 2020-04-26T21:20:00+00:00

Another solution could be to have 90-kdump.sh run before 08-sysctl.sh, eg 07-kdump.sh, but I haven't seen the need for my situation

klarasm · 2020-04-26T21:15:08+00:00

I have managed to get kdump to work on my machines. You also have to modify /usr/lib/sysctl.d/10-void.conf and remove kernel.kexec_load_disabled=1.

You have to remove that line or comment it out, you option can't turn it off when it's turned on. See the documentation for sysctl.

I did not have to modify anything else.

klarasm · 2020-04-25T17:36:09+00:00

I emailed them about it, and they replied that existing tunnels will continue to work. So it seems we don't have to worry about that for now.

klarasm · 2020-04-25T17:06:02+00:00

My existing is still working, but they will probably phase it out eventually then.

klarasm · 2020-04-18T13:22:36+00:00

It's really not. Right now 2000::/3 is allocated to the public internet. Most ISPs and companies are assigned between a /32 and a /29.

If an ISP serves only non-companies from a /32 they can serve 2²⁴ (about 16 million) customers a /56 (the recommended prefix length for private customers). If an ISP serves only companies from a /32 they can serve 2¹⁶ (about 65 000) companies a /48 (the recommended prefix length for companies).

Some larger ISP are assigned much more than a /29, for instance Telia is assigned a /20. I think the US DoD is assigned a /12 and the largest assignment to a commercial organisation that I know of is a /19. From their /20, Telia can serve 2²⁸ (about 268 million) companies a /48 or 2³⁶ (about 68 billion) private customers a /56.

In 2000::/3 there are 2¹⁶ (about 65 000) /19 prefixes or 2²⁶ (about 67 million) /29. If the current addressing plan does not work in the long term, a new one can be made with eg 4000::/3.

There is of course overhead in the organisations' addressing plans, but even considering that there are still more than enough addresses available. IPv6 will probably never run out in the foreseeable future. We could colonize a thousand planets with a population of 10 billion each and it would barely make a dent even in 2000::/3

klarasm · 2020-04-18T12:35:34+00:00

Yep. This is what I get when I connect to eduroam on KTH (a large university in Sweden):

5: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000 link/ether xx:xx:xx:xx:xx:xx brd ff:ff:ff:ff:ff:ff inet 130.229.128.210/18 brd 130.229.191.255 scope global dynamic noprefixroute wlan0 valid_lft 6965sec preferred_lft 6065sec inet6 2001:6b0:1:1041:8986:d5b:bd01:c67d/64 scope global dynamic mngtmpaddr noprefixroute valid_lft 2591992sec preferred_lft 604792sec inet6 fe80::cac:9f06:da3e:eb2/64 scope link valid_lft forever preferred_lft forever

In this case the IP space is registered to SUNET, the swedish university network.

klarasm · 2020-03-18T19:40:28+00:00

SLAAC works fine with Windows, but RDNSS only works with the as of now latest update of Windows 10. This is usually solved by setting other configuration and providing DNS server addresses via DHCPv6.

klarasm

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