# SSH issues on SOME hosts in 2.6.38-r6 >= kernels

## frogstarr78

Current kernel 2.6.37-r4, if I attempt to update to 2.6.38-r6, 2.6.39-r3, or 3.0.6, I can access the internet and most hosts via ssh, but some hosts just timeout. Reboot back into 2.6.37-r4 and they work fine. 

In the newer kernel's I receive "not route to host" errors. Trace or ping them and they fail. My system is on a private lan w/ a reserved IP. I've reinstalled OpenSSH, tried different ports on the switch, and changed the firewall to use a DHCP IP. No change.

```
lspci | grep Ethernet

02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 02)

03:06.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL-8169 Gigabit Ethernet (rev 10)

```

```
grep -ir Realtek /usr/src/linux/.config

CONFIG_REALTEK_PHY=y

CONFIG_SND_HDA_CODEC_REALTEK=y
```

Any ideas?

# emerge --info

Portage 2.1.10.11 (default/linux/amd64/10.0/desktop, gcc-4.4.5, glibc-2.12.2-r0, 2.6.37-gentoo-r4 x86_64)

=================================================================

System uname: Linux-2.6.37-gentoo-r4-x86_64-AMD_Athlon-tm-_64_X2_Dual_Core_Processor_3800+-with-gentoo-2.0.3

Timestamp of tree: Thu, 24 Nov 2011 05:15:01 +0000

app-shells/bash:          4.1_p9

dev-java/java-config:     2.1.11-r3

dev-lang/python:          2.6.6-r2, 2.7.2-r3, 3.1.4-r3

dev-util/cmake:           2.8.4-r1

dev-util/pkgconfig:       0.26

sys-apps/baselayout:      2.0.3

sys-apps/openrc:          0.8.3-r1

sys-apps/sandbox:         2.5

sys-devel/autoconf:       2.13, 2.68

sys-devel/automake:       1.9.6-r3, 1.10.3, 1.11.1

sys-devel/binutils:       2.21.1-r1

sys-devel/gcc:            4.4.5, 4.5.3-r1

sys-devel/gcc-config:     1.4.1-r1

sys-devel/libtool:        2.4-r1

sys-devel/make:           3.82-r1

sys-kernel/linux-headers: 2.6.39 (virtual/os-headers)

sys-libs/glibc:           2.12.2

Repositories: gentoo kde-sunset ruby lua java-overlay xen

ACCEPT_KEYWORDS="amd64"

ACCEPT_LICENSE="* -@EULA"

CBUILD="x86_64-pc-linux-gnu"

CFLAGS="-march=athlon64 -O2 -pipe"

CHOST="x86_64-pc-linux-gnu"

CONFIG_PROTECT="/etc /usr/share/gnupg/qualified.txt /usr/share/maven-bin-2.2/conf /var/bind /var/lib/hsqldb /var/qmail/alias /var/qmail/control"

CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/env.d /etc/env.d/java/ /etc/fonts/fonts.conf /etc/gconf /etc/gentoo-release /etc/php/apache2-php5.3/ext-active/ /etc/php/cgi-php5.3/ext-active/ /etc/php/cli-php5.3/ext-active/ /etc/revdep-rebuild /etc/sandbox.d /etc/terminfo /etc/texmf/language.dat.d /etc/texmf/language.def.d /etc/texmf/updmap.d /etc/texmf/web2c"

CXXFLAGS="-march=athlon64 -O2 -pipe"

DISTDIR="/usr/portage/distfiles"

EMERGE_DEFAULT_OPTS="--oneshot --quiet --autounmask=n"

FEATURES="assume-digests binpkg-logs distlocks ebuild-locks fixlafiles fixpackages news parallel-fetch protect-owned sandbox sfperms strict unknown-features-warn unmerge-logs unmerge-orphans userfetch"

FFLAGS=""

GENTOO_MIRRORS="http://gentoo.osuosl.org/ http://ftp.ucsb.edu/pub/mirrors/linux/gentoo/ http://mirror.its.uidaho.edu/pub/gentoo/ http://mirror.usu.edu/mirrors/gentoo/ ftp://ftp.wallawalla.edu/pub/mirrors/ftp.gentoo.org"

LANG="en_US.UTF-8"

LDFLAGS="-Wl,-O1 -Wl,--as-needed"

LINGUAS="en en_US"

MAKEOPTS="-j2"

PKGDIR="/usr/portage/packages"

PORTAGE_CONFIGROOT="/"

PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --compress --force --whole-file --delete --stats --timeout=180 --exclude=/distfiles --exclude=/local --exclude=/packages"

PORTAGE_TMPDIR="/var/tmp"

PORTDIR="/usr/portage"

PORTDIR_OVERLAY="/var/lib/layman/kde-sunset /var/lib/layman/ruby /var/lib/layman/lua /var/lib/layman/java-overlay /var/lib/layman/xen"

SYNC="rsync://rsync8.us.gentoo.org/gentoo-portage"

USE="X a52 aac acl acpi alsa amd64 bash-completion berkdb bluetooth branding bzip2 cairo cdda cdr cli consolekit cracklib crypt cups cxx dri dts dvd dvdr emboss encode exif fam firefox flac fortran gdbm gdu gif gtk iconv idn ipv6 jpeg lcms ldap libnotify m3dnow m3dnowext mad mmx mng modules mp3 mp4 mpeg mudflap multilib ncurses nls nptl nptlonly ogg opengl openmp pam pango pcre pdf policykit ppds pppd qt3support qt4 readline sdl session spell sse sse2 ssl startup-notification svg sysfs tcpd tiff truetype udev unicode usb vim-syntax vorbis x264 xcb xinerama xml xorg xulrunner xv xvid zlib" ALSA_CARDS="ali5451 als4000 atiixp atiixp-modem bt87x ca0106 cmipci emu10k1x ens1370 ens1371 es1938 es1968 fm801 hda-intel intel8x0 intel8x0m maestro3 trident usb-audio via82xx via82xx-modem ymfpci" ALSA_PCM_PLUGINS="adpcm alaw asym copy dmix dshare dsnoop empty extplug file hooks iec958 ioplug ladspa lfloat linear meter mmap_emul mulaw multi null plug rate route share shm softvol" APACHE2_MODULES="actions alias auth_basic authn_alias authn_anon authn_dbm authn_default authn_file authz_dbm authz_default authz_groupfile authz_host authz_owner authz_user autoindex cache cgi cgid dav dav_fs dav_lock deflate dir disk_cache env expires ext_filter file_cache filter headers include info log_config logio mem_cache mime mime_magic negotiation rewrite setenvif speling status unique_id userdir usertrack vhost_alias" APACHE2_MPMS="worker" CALLIGRA_FEATURES="kexi words flow plan stage tables krita karbon braindump" CAMERAS="ptp2" COLLECTD_PLUGINS="df interface irq load memory rrdtool swap syslog" ELIBC="glibc" GPSD_PROTOCOLS="ashtech aivdm earthmate evermore fv18 garmin garmintxt gpsclock itrax mtk3301 nmea ntrip navcom oceanserver oldstyle oncore rtcm104v2 rtcm104v3 sirf superstar2 timing tsip tripmate tnt ubx" INPUT_DEVICES="keyboard mouse" KERNEL="linux" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" LINGUAS="en en_US" PHP_TARGETS="php5-3" RUBY_TARGETS="ruby18 jruby" USERLAND="GNU" VIDEO_CARDS="nv nvidia vesa fbdev" XTABLES_ADDONS="quota2 psd pknock lscan length2 ipv4options ipset ipp2p iface geoip fuzzy condition tee tarpit sysrq steal rawnat logmark ipmark dhcpmac delude chaos account"

Unset:  CPPFLAGS, CTARGET, INSTALL_MASK, LC_ALL, PORTAGE_BUNZIP2_COMMAND, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_OPTS

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## Veldrin

 *Quote:*   

> In the newer kernel's I receive "not route to host" errors. Trace or ping them and they fail.

 Could you compare routing tables (route -n, or netstat -rnv) between the working and a non working kernel. 

also compare the interface configs. 

V.

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## cach0rr0

a few shots in the dark:

MTU settings can make for some really screwy behaviour 

maybe the presence of ipv6 is problematic in one, but not the other; or maybe the hosts where things fail have ipv6 entries in DNS, that your system shits itself trying to handle on newer kernels for whatever reason

i have nothing scientific to guess really

----------

