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authorjob@openbsd.org <job@openbsd.org>2018-04-04 15:12:17 +0000
committerDamien Miller <djm@mindrot.org>2018-04-06 14:20:33 +1000
commit5ee8448ad7c306f05a9f56769f95336a8269f379 (patch)
treefac0e97f27145aeef62714ac0f50651ef4621df9 /ssh_config.5
parent424b544fbda963f973da80f884717c3e0a513288 (diff)
upstream: Update default IPQoS in ssh(1), sshd(8) to DSCP AF21 for
interactive and CS1 for bulk AF21 was selected as this is the highest priority within the low-latency service class (and it is higher than what we have today). SSH is elastic and time-sensitive data, where a user is waiting for a response via the network in order to continue with a task at hand. As such, these flows should be considered foreground traffic, with delays or drops to such traffic directly impacting user-productivity. For bulk SSH traffic, the CS1 "Lower Effort" marker was chosen to enable networks implementing a scavanger/lower-than-best effort class to discriminate scp(1) below normal activities, such as web surfing. In general this type of bulk SSH traffic is a background activity. An advantage of using "AF21" for interactive SSH and "CS1" for bulk SSH is that they are recognisable values on all common platforms (IANA https://www.iana.org/assignments/dscp-registry/dscp-registry.xml), and for AF21 specifically a definition of the intended behavior exists https://tools.ietf.org/html/rfc4594#section-4.7 in addition to the definition of the Assured Forwarding PHB group https://tools.ietf.org/html/rfc2597, and for CS1 (Lower Effort) there is https://tools.ietf.org/html/rfc3662 The first three bits of "AF21" map to the equivalent IEEEE 802.1D PCP, IEEE 802.11e, MPLS EXP/CoS and IP Precedence value of 2 (also known as "Immediate", or "AC_BE"), and CS1's first 3 bits map to IEEEE 802.1D PCP, IEEE 802.11e, MPLS/CoS and IP Precedence value 1 ("Background" or "AC_BK"). OK deraadt@, "no objection" djm@ OpenBSD-Commit-ID: d11d2a4484f461524ef0c20870523dfcdeb52181
Diffstat (limited to 'ssh_config.5')
-rw-r--r--ssh_config.510
1 files changed, 6 insertions, 4 deletions
diff --git a/ssh_config.5 b/ssh_config.5
index 71705cab..010bca47 100644
--- a/ssh_config.5
+++ b/ssh_config.5
@@ -33,8 +33,8 @@
.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
.\"
-.\" $OpenBSD: ssh_config.5,v 1.268 2018/02/23 07:38:09 jmc Exp $
-.Dd $Mdocdate: February 23 2018 $
+.\" $OpenBSD: ssh_config.5,v 1.269 2018/04/04 15:12:17 job Exp $
+.Dd $Mdocdate: April 4 2018 $
.Dt SSH_CONFIG 5
.Os
.Sh NAME
@@ -984,9 +984,11 @@ If one argument is specified, it is used as the packet class unconditionally.
If two values are specified, the first is automatically selected for
interactive sessions and the second for non-interactive sessions.
The default is
-.Cm lowdelay
+.Cm af21
+.Ar (Low-Latency Data)
for interactive sessions and
-.Cm throughput
+.Cm cs1
+.Ar (Lower Effort)
for non-interactive sessions.
.It Cm KbdInteractiveAuthentication
Specifies whether to use keyboard-interactive authentication.