Package: openssh-server Version: 1:6.7p1-5 Severity: normal Seems to me that sshd should, but does not, set TCP_NODELAY on the port used for X11 forwarding. I am not sure about other forwarded ports; sshd seems to set TCP_NODELAY and also IPTOS_LOWDELAY on the "command" connection only.
Quoting from http://www.openssh.com/txt/release-3.1 - TCP_NODELAY set on X11 and TCP forwarding endpoints Is this a bug that could be fixed? Thanks, Paul Paul Szabo p...@maths.usyd.edu.au http://www.maths.usyd.edu.au/u/psz/ School of Mathematics and Statistics University of Sydney Australia -- System Information: Debian Release: 8.2 APT prefers stable APT policy: (500, 'stable') Architecture: i386 (x86_64) Kernel: Linux 3.16.7-ckt11-pk07.14-amd64 (SMP w/8 CPU cores) Locale: LANG=C.UTF-8, LC_CTYPE=C.UTF-8 (charmap=UTF-8) Shell: /bin/sh linked to /bin/bash Init: systemd (via /run/systemd/system) Versions of packages openssh-server depends on: ii adduser 3.113+nmu3 ii debconf [debconf-2.0] 1.5.56 ii dpkg 1.17.26 ii init-system-helpers 1.22 ii libc6 2.19-18+deb8u1 ii libcomerr2 1.42.12-1.1 ii libgssapi-krb5-2 1.12.1+dfsg-19+deb8u1 ii libkrb5-3 1.12.1+dfsg-19+deb8u1 ii libpam-modules 1.1.8-3.1 ii libpam-runtime 1.1.8-3.1 ii libpam0g 1.1.8-3.1 ii libselinux1 2.3-2 ii libssl1.0.0 1.0.1k-3+deb8u1 ii libwrap0 7.6.q-25 ii lsb-base 4.1+Debian13+nmu1 ii openssh-client 1:6.7p1-5 ii openssh-sftp-server 1:6.7p1-5 ii procps 2:3.3.9-9 ii zlib1g 1:1.2.8.dfsg-2+b1 Versions of packages openssh-server recommends: ii ncurses-term 5.9+20140913-1 ii xauth 1:1.0.9-1 Versions of packages openssh-server suggests: pn molly-guard <none> pn monkeysphere <none> pn rssh <none> pn ssh-askpass <none> pn ufw <none> -- debconf information excluded