DSM-G600, DNS-3xx and NSA-220 Hack Forum

What exactlyis the purpose of this arrangement?  You would have to telnet into the DNS-323 to connect to the router via the USB/Serial/Console and it would probably be a lot simpler to telnet directly into the router completely bypassing the DNS-323 - this type of "remote" access is, for want of a better way to put it, not only the norm with routers, but the expected method of access - I maintain my clients' "country-spanning WANs" from a single location without having to drive from site to site, and I've also participated in implementing "globe-spanning WANs" for a number of international firms - site visits are typically made only for the initial hardware installation or in case of equipment failure.

This is not a Cisco forum so I will not go into any depth on this, but if you're unable to telnet into the router from a remote location, you need to check the ACLs that control the VTY interface and/or the WAN interface - one of those (or the firewall) will be blocking your connection.

Last edited by fordem (2012-09-19 17:40:51)

Hi fordem,

fordem wrote:

What exactlyis the purpose of this arrangement?  You would have to telnet into the DNS-323 to connect to the router via the USB/Serial/Console and it would probably be a lot simpler to telnet directly into the router completely bypassing the DNS-323 - this type of "remote" access is, for want of a better way to put it, not only the norm with routers, but the expected method of access - I maintain my clients' "country-spanning WANs" from a single location without having to drive from site to site, and I've also participated in implementing "globe-spanning WANs" for a number of international firms - site visits are typically made only for the initial hardware installation or in case of equipment failure.

I'm system admin and would like extend my knowledge to cisco world. I'm supporting about 100 servers which each have remote console (HP servers with built in ILO or OA modules) in case if NW connection from any reason is not available. I'd like achieve similar functionality for my cisco router.
This is my first try with combination of DNS-323, USB to RS232 (PL2303 chip) and cisco router (model 1721). The approach is not the best perhaps.
I've googled and found that cisco switch 2909 (up to 8 devices possible to connect) would provide me what I'm looking for but it would cost me about 200EUR (ebay)! DNS-323 and PL2303 I have already that's why I started thinking about using it.

fordem wrote:

This is not a Cisco forum so I will not go into any depth on this, but if you're unable to telnet into the router from a remote location, you need to check the ACLs that control the VTY interface and/or the WAN interface - one of those (or the firewall) will be blocking your connection.

I agree that I should search remote access on cisco forum and google. You bet I will. Thanks for the hints.

Hello again after 2years.

I found some reference to this thread and would like to update some info about netcat which might be handy for someone.
I have found issues with stty settings which caused me headache.

I wrote this script but the issues were never overcame.

Code:

#!/ffp/bin/bash
#
# Purpose of this script is to restart USB serial service
#
# v0.1  20.09.2012      Initial version
#

# Make sure only root can run this script
if [ "$(id -u)" != "0" ]; then
   echo "This script must be run as root" 1>&2
   exit 1
fi

# General variables
PATH=/ffp/bin:/ffp/sbin
MOD_LOC='/ffp/system'
DEVICE='/dev/ttyUSB0'
MODULE1=usbserial
#MODULE1_PARAMS="vendor=0x03eb product=0x204b"
MODULE2=pl2303
MODULE1_CHECK=`lsmod |awk '{print $1}' |grep $MODULE1`
MODULE2_CHECK=`lsmod |awk '{print $1}' |grep $MODULE2`
#STTY_OPTS="9600 -parenb cs8 -cstopb -ixon -clocal -ignbrk -icanon -brkint -icrnl ixoff -imaxbel -opost -onlcr -isig -icanon -iexten -echo -echoe -echok -echoctl -echoke -hupcl "
NETCAT_IP='10.x.x.x'
NETCAT_PORT=5000

eval parm1=$1

# Help to display the options
function help {
echo "USB serial service v0.1"
echo ""
echo "USAGE"
echo "console   [start|stop|restart|status|terminal]"
echo "-h                Invoke this help"
echo ""
#exit 0
}

# Wrong usage. All not allowed options.
function wrong {
echo "Wrong USAGE! See allowed syntax below."
echo ""
echo ""
help
}

# Check if kernel modules are loaded
function status {
echo "Modules loaded: $MODULE1_CHECK $MODULE2_CHECK"
}

# Unload kernel modules
function stop {
if [ "$MODULE2" == "$MODULE2_CHECK" ] ;then
  rmmod $MODULE2
  echo "Unloading module $MODULE2"
else
  echo "Module $MODULE2 is not loaded"
fi

if [ "$MODULE1" == "$MODULE1_CHECK" ] ;then
  rmmod $MODULE1
  echo "Unloading module $MODULE1"
else
  echo "Module $MODULE1 is not loaded"
fi

# Clean variables
MODULE1_CHECK=
MODULE2_CHECK=
}

# Load kernel modules
function start {
if [ "$MODULE1" == "$MODULE1_CHECK" ] ;then
  echo "Module $MODULE1 is already running"
else
  insmod $MOD_LOC/$MODULE1.ko
  echo "Loading kernel module $MODULE1"
fi

if [ "$MODULE2" == "$MODULE2_CHECK" ] ;then
  echo "Module $MODULE2 is already running"
else
  insmod $MOD_LOC/$MODULE2.ko
  echo "Loading kernel module $MODULE2"
fi

device
netcat
terminal
}

# Create device file
function device {
if [ -c $DEVICE ]; then
  echo "Device file $DEVICE already exist"
else
  mknod $DEVICE c 188 0
  echo "Device file $DEVICE has been created"
fi
}

# NetCat
function netcat {
echo "Starting NetCat."
#nohup nc -l -p 5000 </dev/ttyUSB0 >/dev/ttyUSB0 &
nc -l -p 5000 </dev/ttyUSB0 >/dev/ttyUSB0 &
}

# Restart
function restart {
stop
sleep 1
start
}

# Setup stty values
function terminal {
echo "Configuring terminal settings"
#stty -F $DEVICE cs8 9600 time 1 -ignbrk -brkint -icrnl -imaxbel -opost -onlcr -isig -icanon -iexten -echo -echoe -echok -echoctl -echoke -noflsh ixon ixoff -clocal -crtscts
#stty -F $DEVICE 9600 -parenb cs8 -cstopb -ixon -clocal -ignbrk time 1 -icanon -brkint -icrnl ixoff \
#-imaxbel -opost -onlcr -isig -icanon -iexten -echo -echoe -echok -echoctl -echoke
stty -F /dev/ttyUSB0 9600 -parenb cs8 -cstopb -ixon -clocal -hupcl -ignbrk -icanon -echo

#for option in $STTY_OPTS ;do stty -F $DEVICE $option ;done
#echo "Terminal set"
}

if [[ $# -eq 0 ]]; then
  echo "Missing parameter!"
  echo ""
  echo ""
  help
else
  case $1 in
          start)     start;;
          stop)      stop;;
          restart)   restart;;
          status)    status;;
          terminal)  terminal;;
          netcat)    netcat;;
          -h)        help;;
          *)         wrong;;
  esac
fi

Now I tried to compile latest version of minicom 2.7.1 on my NAS (I'm on FW 1.10 and FFP 0.5) and it went fine and relatively fast (about 15min).
Minicom works fine for me and now I don't have reason to use netcat any longer.
I will try contact Fonz to publish it under section 0.5 on his site if will agree.

BR,
Peter

Last edited by PeterZ (2014-11-21 16:23:02)