Monthly Archives: May 2013

IPv6: RIPE reverse DNS delegation, tinydns PTR setup & classless delegation

RIPE explains how to set up IPv6 reverse DNS delegation pretty good here but it can be a bit confusing at times. Basically you have to simply send something like that to auto-dbm@ripe.net if your allocation is 2b02:0b08::/32

domain: 8.0.b.0.2.0.b.2.ip6.arpa descr: Reverse delegation for Something Inc. admin-c: SMTH-RIPE tech-c: SMTH-RIPE zone-c: SMTH-RIPE nserver: ns1.something.com nserver: ns2.something.com changed: someone@something.com 20130531 source: RIPE mnt-by: SOMETHING-MNT password: yourmntpasswd

ns1.something.com and ns2.something.com are only reachable via IPv4 at this time, but since most IPv6 hosts are hopefully dual-stacked, it shouldn’t matter. Before you tell RIPE to delegate to you, add something like this to tinydns:

Z8.0.b.0.2.0.b.2.ip6.arpa:ns1.something.com:dnsmaster.something.com:1:86400:86400:86401:86400:86400: &8.0.b.0.2.0.b.2.ip6.arpa::ns1.something.com &8.0.b.0.2.0.b.2.ip6.arpa::ns2.something.com

^1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.1.0.0.0.0.0.0.0.8.0.b.0.2.0.b.2.ip6.arpa:some-example-host.something.com

The above will set up tinydns to serve PTR requests for your allocation and also sets up an example PTR record for 2b02:0b08:0:1::1 resolving to some-example-host.something.com.

Now, let’s say you have a customer with his own /64 assignment and you want to forward PTR requests for his assignment to his DNS a.k.a. classless delegation. Then you would set up the following in tinydns:

&7.0.0.0.0.0.0.0.8.0.b.0.2.0.b.2.ip6.arpa::dns1.customer.com:3600 &7.0.0.0.0.0.0.0.8.0.b.0.2.0.b.2.ip6.arpa::dns2.customer.com:3600

That’s it. To confirm it’s working you can query your own tinydns:

# dig @ip-of-your-tinydns -x 2b02:0b08:0:7::0001


;; QUESTION SECTION:

;1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.7.0.0.0.0.0.0.0.8.0.b.0.2.0.b.2.ip6.arpa. IN PTR

;; AUTHORITY SECTION: 7.0.0.0.0.0.0.0.8.0.b.0.2.0.b.2.ip6.arpa. 3600 IN NS dns1.customer.com. 7.0.0.0.0.0.0.0.8.0.b.0.2.0.b.2.ip6.arpa. 3600 IN NS dns2.customer.com.

Quick copy & paste how-to: Install KVM on CentOS 6

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CentOS 6.7 64bit ISO: ftp://ftp.hosteurope.de/mirror/centos.org/6.7/isos/x86_64/CentOS-6.7-x86_64-netinstall.iso


URL for netinstall: ftp://ftp.hosteurope.de/mirror/centos.org/6.7/os/x86_64
LVM vg: 100%
Host: lv_root / 200 GB
vi /etc/sysconfig/selinux

SELINUX=disabled
yum install wget screen lynx vim kvm libvirt python-virtinst qemu-kvm ncftp tigervnc tigervnc-server system-config-firewall-tui xterm twm bridge-utils virt-manager openssh-askpass openssh-clients dbus-python dbus
yum groupinstall Desktop
yum update
/etc/init.d/messagebus start
system-config-firewall-tui

-> disable firewall
vi /etc/sysconfig/vncservers

VNCSERVERS="10:root"

VNCSERVERARGS[10]="-geometry 1024x768"
vi /etc/ssh/sshd_config

Port 450

PermitRootLogin without-password
adduser admin

passwd admin
chkconfig rpcidmapd off

chkconfig rpcgssd off

chkconfig nfslock off

chkconfig netfs off

chkconfig rpcbind off

chkconfig dnsmasq off

chkconfig NetworkManager off

chkconfig messagebus off
vncpasswd
vi /root/.vnc/xstartup
#!/bin/sh

[ -r /etc/sysconfig/i18n ] && . /etc/sysconfig/i18n

export LANG

export SYSFONT

vncconfig -iconic &

unset SESSION_MANAGER

unset DBUS_SESSION_BUS_ADDRESS

OS=`uname -s`

if [ $OS = 'Linux' ]; then

  case "$WINDOWMANAGER" in

    *gnome*)

      if [ -e /etc/SuSE-release ]; then

        PATH=$PATH:/opt/gnome/bin

        export PATH

      fi

      ;;

  esac

fi

if [ -x /etc/X11/xinit/xinitrc ]; then

  exec /etc/X11/xinit/xinitrc

fi

if [ -f /etc/X11/xinit/xinitrc ]; then

  exec sh /etc/X11/xinit/xinitrc

fi

[ -r $HOME/.Xresources ] && xrdb $HOME/.Xresources

xsetroot -solid grey

xterm -geometry 80x24+10+10 -ls -title "$VNCDESKTOP Desktop" &

twm &
chmod 755 /root/.vnc/xstartup
vi /etc/sysconfig/network-scripts/ifcfg-eth0

DEVICE=eth0

BOOTPROTO=none

# BROADCAST=x.x.x.x

# DNS1=x.x.x.x

# GATEWAY=x.x.x.x

HWADDR=00:25:90:38:66:c6

# IPADDR=x.x.x.x

# NETMASK=x.x.x.x

NM_CONTROLLED=yes

ONBOOT=yes

TYPE=Ethernet

# DNS2=x.x.x.x

IPV6INIT=no

USERCTL=no

BRIDGE=br0
vi /etc/sysconfig/network-scripts/ifcfg-br0

DEVICE=br0

TYPE=Bridge

BOOTPROTO=none

ONBOOT=yes

DELAY=0

NM_CONTROLLED=no

BROADCAST=x.x.x.x

DNS1=x.x.x.x

GATEWAY=x.x.x.x

IPADDR=x.x.x.x

NETMASK=x.x.x.x

DNS2=x.x.x.x

IPV6INIT=no

USERCTL=no
vi /etc/sysctl.conf

net.ipv4.ip_forward = 1

net.ipv6.conf.all.disable_ipv6 = 1

net.ipv6.conf.default.disable_ipv6 = 1
In /etc/postfix/main.cf:

inet_protocols = ipv4
reboot
Add hostname to /etc/hosts

/etc/init.d/vncserver start

VNC connect to host:10

virt-manager:

localhost ->

1. Virtual Networks -> default -> Basic details: device: (or virbr0), Autostart: unchecked -> Apply

2. Storage -> + (add) -> logical, Name “vm-lvm” -> Build Pool: unchecked -> Source Name: name of existing LVM volume group -> Finish

Done!

How to: cgminer (Bitcoin, Litecoin etc.) + AMD Radeon driver install on CentOS

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UPDATE 7/7/13: If you want to use Catalyst drivers version 12.8 you will find that X won’t start (error msg: /usr/lib/xorg/modules/drivers/fglrx_drv.so: undefined symbol: noXFree86DRIExtension) if you installed CentOS 6.4. Catalyst > 12.8 will work fine. To fix that, you can downgrade to the Xorg version that ships with CentOS 6.3:

yum --disablerepo=\* --enablerepo=C6.3\* downgrade xorg\*
(You may also need to do: yum remove xorg-x11-drv-modesetting)

Do this before you install Catalyst!
UPDATE END.

Here’s my how-to for cgminer / AMD Radeon drivers under CentOS 6.4, 32bit in this example. You can basically copy & paste every line and you should end up with a working mining rig.

Install required packages:

yum install wget system-config-firewall-tui openssh-clients kernel-devel-2.6.32-358.el6.i686 libcurl-devel ncurses-devel compat-libstdc++-33 screen xterm yum groupinstall "X Window System" "Development tools"

Download and extract cgminer 3.7.2 – later versions don’t support GPU mining:

cd /root wget http://ck.kolivas.org/apps/cgminer/3.7/cgminer-3.7.2.tar.bz2 tar xjvf cgminer-3.7.2.tar.bz2

Download AMD APP and ADL SDKs for cgminer compilation from:

AMD APP SDK: http://developer.amd.com/tools-and-sdks/heterogeneous-computing/amd-accelerated-parallel-processing-app-sdk/downloads
AMD ADL SDK: http://developer.amd.com/tools-and-sdks/graphics-development/display-library-adl-sdk

Install AMD APP SDK:

cd /opt tar xvzf /root/AMD-APP-SDK-v2.8-lnx32.tgz cd / tar xvzf /opt/icd-registration.tgz cd /opt tar xvzf AMD-APP-SDK-v2.8-RC-lnx32.tgz ln -s /opt/AMD-APP-SDK-v2.8-RC-lnx32/include/CL /usr/include ln -s /opt/AMD-APP-SDK-v2.8-RC-lnx32/lib/x86/* /usr/lib/

Install AMD ADL SDK:

cd /root mkdir ADL mv ADL_SDK_5.0.zip ADL cd ADL unzip ADL_SDK_5.0.zip cp include/*.h /root/cgminer-3.7.2/ADL_SDK

Build cgminer for Litecoin (with scrypt support):

cd /root/cgminer-3.7.2 CFLAGS="-O2 -Wall -march=native -I/opt/AMD-APP-SDK-v2.8-RC-lnx32/include" LDFLAGS="-L/opt/AMD-APP-SDK-v2.8-RC-lnx32/lib/x86" ./configure --enable-scrypt make make install (if you want to run the cgminer binary from everywhere)

Install fglrx AMD graphics card drivers:

AMD Catalyst driver (fglrx) from: http://support.amd.com/us/gpudownload/linux/Pages/radeon_linux.aspx

(e.g.

cd /root wget http://www2.ati.com/drivers/linux/amd-catalyst-13.4-linux-x86.x86_64.zip

)

unzip amd-catalyst-13.4-linux-x86.x86_64.zip chmod 700 amd-catalyst-13.4-linux-x86.x86_64.run ./amd-catalyst-13.4-linux-x86.x86_64.run --buildpkg RedHat/RHEL6 rpm -Uvh fglrx_p_i_c-12.104-1.i386.rpm


reboot

amdconfig --adapter=all --initial

If your mining rig is headless you can start X in a screen session:

screen xinit

Detach screen session: CTRL+A+D

Create cgminer.sh and put this into the file:

export GPU_USE_SYNC_OBJECTS=1 export GPU_MAX_ALLOC_PERCENT=100 export DISPLAY=:0

cgminer --scrypt ...your parameters go here...

Make it executable:

chmod 700 cgminer.sh

Configure cgminer parameters as needed and start mining (./cgminer.sh). Done!

JunOS: Finding SNMP object identifiers for your Juniper device

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Step 1: Download the approriate MIBs from Juniper at this link.

Step 2: grep through the MIB .txt files for the string that you’re looking for, e.g. grep -i prefixes *.txt. This will give you some clues like:

mib-jnx-bgpmib2.txt: jnxBgpM2PrefixInPrefixes
mib-jnx-bgpmib2.txt: jnxBgpM2PrefixInPrefixesAccepted
mib-jnx-bgpmib2.txt: jnxBgpM2PrefixInPrefixesRejected
mib-jnx-bgpmib2.txt: jnxBgpM2PrefixOutPrefixes

Step 3: On your Juniper, walk through the SNMP object names until you found what you’re looking for:

admin@router> show snmp mib walk jnxBgpM2
[…]
jnxBgpM2PrefixOutPrefixes.0.1.1 = 10
jnxBgpM2PrefixOutPrefixes.1.1.1 = 10
jnxBgpM2PrefixOutPrefixes.2.2.1 = 1

(jnxBgpM2PrefixCountersTable instead of jnxBgpM2 works too and saves you some time – check e.g. http://www.oidview.com/mibs/2636/BGP4-V2-MIB-JUNIPER.html)

Step 4: Now, if you want to monitor two of these objects, for example 0.1.1 and 2.2.1 with e.g. MRTG, you cannot simply specify

Target[router_prefixout]: jnxBgpM2PrefixOutPrefixes.0.1.1&jnxBgpM2PrefixOutPrefixes.2.2.1:yourcommunity@router-ip-address:::::2

because that just won’t work. Don’t ask me why, I’m an SNMP n00b and I couldn’t care less about SNMP. :-) Instead you will need the object identifier, which for BGP you could find here: http://www.oidview.com/mibs/2636/BGP4-V2-MIB-JUNIPER.html respectively here at oidview.com for all Juniper MIBs: http://www.oidview.com/mibs/2636/md-2636-1.html. In that document you would search for object name jnxBgpM2PrefixOutPrefixes and you would find that 1.3.6.1.4.1.2636.5.1.1.2.6.2.1.10 is the corresponding object identifier. So, your final config will look like this:

Target[router_prefixout]: 1.3.6.1.4.1.2636.5.1.1.2.6.2.1.10.0.1.1&1.3.6.1.4.1.2636.5.1.1.2.6.2.1.10.2.2.1:yourcommunity@router-ip-address:::::2

JunOS: Make sshd listen on another port than 22

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There’s no setting in JunOS (M series) that makes it possible to move sshd to another port than 22 by default. Here’s a dirty workaround:

We want sshd to listen on port 450.

% grep 450 /etc/services
tserver 450/tcp
tserver 450/udp

Comment the lines starting with ssh in /etc/inetd.conf and add tserver instead with the same parameters:

# ssh stream tcp/rt=shared nowait/75/2 root /usr/sbin/sshd sshd -i -f /var/etc/sshd_conf
# ssh stream tcp6/rt=shared nowait/75/2 root /usr/sbin/sshd sshd -i -f /var/etc/sshd_conf
tserver stream tcp/rt=shared nowait/75/2 root /usr/sbin/sshd sshd -i -f /var/etc/sshd_conf
tserver stream tcp6/rt=shared nowait/75/2 root /usr/sbin/sshd sshd -i -f /var/etc/sshd_conf

Add your desired port to /var/etc/sshd_conf:

PermitRootLogin no
Protocol 2
Port 450

Then restart inetd:

kill -HUP PID_OF_INETD

Done. Changes will be lost on reboot or software upgrade. You could set up a cronjob to check and add the lines to inetd.conf / sshd_conf automatically if needed.