Re: IPQoS values in sshd
Hello Daren, Thank you for your answer, I didn't see it earlier today. This change in current makes sense to me. Regards Le mercredi 8 août 2018 à 06:07:10 UTC+2, Darren Tucker a écrit : On 8 August 2018 at 05:29, Mik J wrote: > Does anyone knows what means lowdelay and thoughput for IPQoS parameter ? > To what DSCP correspond these words >From https://www.openssh.com/specs.html, which documents the most recent release: they're the values specified in RFC1349, the first of the dozen or so attempts to specify the meaning of those few bits (RFCs 2474, 2597, 2598, 3168, 3246, 3260, 3662, 4301, 4594, 5865 and 8325). > I did a capture when writing ls in my terminal and I see DSCP=cs0. > I would have expected something else. The default values have been changed in -current but that change has not yet made it to a release. From https://man.openbsd.org/ssh_config.5: "The default is af21 (Low-Latency Data) for interactive sessions and cs1 (Lower Effort) for non-interactive sessions." -- Darren Tucker (dtucker at dtucker.net) GPG key 11EAA6FA / A86E 3E07 5B19 5880 E860 37F4 9357 ECEF 11EA A6FA (new) Good judgement comes with experience. Unfortunately, the experience usually comes from bad judgement.
Re: join id cannot be integer
On Wed, Aug 08, 2018 at 05:43:08PM +0200, Stefan Sperling wrote: > join and nwid are mutually exclusive commands. Apparently I did not read the join info properly. Thanks for the clue stick and sorry for the noise. Bryan
Re: join id cannot be integer
On Wed, Aug 08, 2018 at 08:25:46AM -0700, Bryan Vyhmeister wrote: > I have not investigated the full scenario here but using the new join > option for wireless network configuration does not seem to work if I use > an ID of 0, 1, or 2 and probably others. Is this expected? The man page > seems to indicate that this should work fine. From ifconfig(8): > > "The id can either be any text string up to 32 characters in length, or > a series of hexadecimal digits up to 64 digits. Any necessary wpakey or > nwkey arguments should be specified on the same line." > > Here is the scenario to test. > > /etc/hostname.iwm0: > join 0 nwid TEST wpakey 1234567890 > dhcp > > This will not work and I will end up associated to the AP but status > will always stay as no network. > > /etc/hostname.iwm0: > join TEST nwid TEST wpakey 1234567890 > dhcp > > This will work as expected. > > Bryan > join and nwid are mutually exclusive commands. What you want in hostname.if is either: join TEST wpakey 1234567890 or the plain old: nwid TEST wpakey 1234567890 The man page talks about ESSIDs in hexstring format. This is useful only if the network name cannot be entirely represented in the ASCII character set since there's no support for character encodings other than ASCII.
join id cannot be integer
I have not investigated the full scenario here but using the new join option for wireless network configuration does not seem to work if I use an ID of 0, 1, or 2 and probably others. Is this expected? The man page seems to indicate that this should work fine. From ifconfig(8): "The id can either be any text string up to 32 characters in length, or a series of hexadecimal digits up to 64 digits. Any necessary wpakey or nwkey arguments should be specified on the same line." Here is the scenario to test. /etc/hostname.iwm0: join 0 nwid TEST wpakey 1234567890 dhcp This will not work and I will end up associated to the AP but status will always stay as no network. /etc/hostname.iwm0: join TEST nwid TEST wpakey 1234567890 dhcp This will work as expected. Bryan
Re: IPQoS values in sshd
Hello David, Thank you for your answer. Indeed, I have (in this case) an agreement with the ISP to I can play with QoS fields. => I don't understand why in the documentation they refer to old ToS field and not DSCP field that everyone use. That would be more logic. I did captures and found ToS 0x10 or 0x8 (transfert) IP (tos 0x10, ttl 64, id 6849, offset 0, flags [DF], proto TCP (6), length 52) According to what I read tos 0x10 = DSCP 2 and tos 0x8 = DSCP 2 ? ToS 0x10 in binary 1010 = dscp 10 => 2 and ToS binary 8 in binary 1000 = dscp 10 => 2 Low delay should be 0x1000 and throughput should be 0x100 https://tools.ietf.org/html/rfc1349 4. Specification of the TOS Field I tried with openbsd 6.3 Also why these values were chosen by default in Openbsd, according to QoS models I would have chosen other values and also used dscp instead of ToS Regards Le mercredi 8 août 2018 à 11:31:39 UTC+2, Dahlberg, David a écrit : Am Dienstag, den 07.08.2018, 19:29 + schrieb Mik J: > Does anyone knows what means lowdelay and thoughput for IPQoS > parameter ? Bits 3 and 4 of old IP TOS field. > To what DSCP correspond these words You have to calculate it yourself. The lowest bit of the 6-bit DSCP is "private". The second and third lowest once have been T and D. I did indeed write a script which translates me a given value from one interpretation into the gazillion other possible interpretations. Maybe I push it to Githup soonish. "T" is e.g. AFx1 and AFx3 equivalents. "L" is e.g. AFx2 and AFx3. > I did a capture when writing ls in my terminal and I see DSCP=cs0. > I would have expected something else. CSx in DSCP directly equates to IP precedence in old TOS interpretation with all the special bits (DTRC0) set to zero. CS0 = DF (default forwarding) is all zero. But honestly, what do you want to set those values for? They have only local meaning -> So you can do something with them in your local network. If you're sending them across a administrative border, they lose meaning (unless something special has been negotiated between you and your ISP) and it is quite possible they are set to zero anyways. With regular internet access, all you can do is set the DSCP to a "well- known" value and hope that there is somebody out there who (a) does process it, (b) interprets the same way as you and (c) he did receive your value unchanged (which is not guaranteed). An example for such well-known values which "may" have "some" effect "somewhere" is mostly EF for VoIP. Cheers David
regarding the hashcat WPA2 PMKID crack
The attack described at https://hashcat.net/forum/thread-7717.html performs a brute-force hash cracking attack on data voluntarily sent by access points which support 802.1x authentication with a pre-shared passphrase and have a feature known as "fast roaming" enabled. At present, OpenBSD-based access points support neither 802.1x authentication nor fast roaming. (There is some 802.1x code in the kernel, but it is only used in client mode and only in conjunction with the wpa_supplicant program from ports.) Lack of 802.1x support means the WPA key configured with ifconfig acts as the pairwise master key (PMK). It has always been possible to capture a 4-way handshake and attempt to crack the passphrase which hashed data exposed during the 4-way handshake is based on. This is referred to as one of the "existing attacks" in the hashcat forum post and this attack vector is even mentioned in the spec (802.11 2012, section 4.10.3.4 "Alternate operations with PSK"): """ This operation has security vulnerabilities when used with a low-entropy key and is recommended to be used only after taking that into account. """ So the bottom line is: - Never rely on WPA passphrases for end-to-end security regardless of how "strong" your passphrase seems to be. WPA passphrases may be used for access control (i.e. authorization) but they provide neither authenticity nor privacy. - If you care, configure a "strong" WPA passphrase on your access point. The maximum length is 63 characters. A command such as pwgen -s 63 will suggest a WPA passphrase which is hard to crack (pwgen is in ports).
Re: how to find reason for computer pausing often?
On Wed, Aug 08, 2018 at 08:59:40AM +0200, Solene Rapenne wrote: > Derek Sivers wrote: > > This past month or so, my Lenovo T440s laptop has started doing strange > > 2-second pauses at random intervals, sometimes a few times per minute. > > > > How would you look for the source of this trouble? There's nothing in > > /var/log showing when it happens. No log entries added there. Where else > > would you look? > > > > The easiest way to spot it in action is with a simple ls : > > > > cd /tmp > > mkdir a b c > > time ls a > > 0m00.00s real 0m00.00s user 0m00.01s system > > time ls b > > 0m03.22s real 0m00.00s user 0m00.01s system # there is the > > random pause > > time ls c > > 0m00.00s real 0m00.00s user 0m00.00s system > > time ls b > > 0m00.00s real 0m00.00s user 0m00.00s system > > > > I've tried it running OpenBSD 6.3 RELEASE, STABLE, and CURRENT. Happens > > with all. > > > > I wiped the entire drive (dd if=/dev/zero) then re-installed from scratch, > > and it still happens. > > > > It happens whether running X or just in the initial raw console without > > startx. > > > > I know it isn't an OpenBSD problem, but any suggestions where you'd look if > > it was you? > > > > Thank you. > > > > - Derek > > Hi Derek > > I think that your hard drive is failing. Is it a SSD? If no, it's > typical of an old failing hard disk. > > Could you try to mount a mfs filesystem and see if your example makes a > pause? That should not trigger any disk read as it's an in-memory > filesystem, if it doesn't block that mean that the hard disk is failing. Thanks for the reply and suggestion. It's an SSD - https://www.cnet.com/products/adata-premier-sp600ns34-solid-state-drive-128-gb-sata-6gb-s/specs/ - but I'll try the MFS thing, too.
Re: how to find reason for computer pausing often?
Derek Sivers wrote: > This past month or so, my Lenovo T440s laptop has started doing strange > 2-second pauses at random intervals, sometimes a few times per minute. > > How would you look for the source of this trouble? There's nothing in > /var/log showing when it happens. No log entries added there. Where else > would you look? > > The easiest way to spot it in action is with a simple ls : > > cd /tmp > mkdir a b c > time ls a > 0m00.00s real 0m00.00s user 0m00.01s system > time ls b > 0m03.22s real 0m00.00s user 0m00.01s system # there is the > random pause > time ls c > 0m00.00s real 0m00.00s user 0m00.00s system > time ls b > 0m00.00s real 0m00.00s user 0m00.00s system > > I've tried it running OpenBSD 6.3 RELEASE, STABLE, and CURRENT. Happens with > all. > > I wiped the entire drive (dd if=/dev/zero) then re-installed from scratch, > and it still happens. > > It happens whether running X or just in the initial raw console without > startx. > > I know it isn't an OpenBSD problem, but any suggestions where you'd look if > it was you? > > Thank you. > > - Derek Hi Derek I think that your hard drive is failing. Is it a SSD? If no, it's typical of an old failing hard disk. Could you try to mount a mfs filesystem and see if your example makes a pause? That should not trigger any disk read as it's an in-memory filesystem, if it doesn't block that mean that the hard disk is failing.
