Thursday, August 3, 2017

7 layer model

Layer 1: Physical The Physical layer consists of the physical media and dumb devices that make up the infrastructure of our networks. This pertains to the cabling and connections such as Category 5e and RJ-45 connectors. Note that this layer also includes light and rays, which pertain to media such as fiber optics and microwave transmission equipment. Attack considerations are aligned with the physical security of site resources. Although not flashy, physical security still bears much fruit in penetration (pen) testing and real-world scenarios.

Layer 2: Data Link The Data Link layer works to ensure that the data it transfers is free of errors. At this layer, data is contained in frames. Functions such as media access control and link establishment occur at this layer. This layer encompasses basic protocols such as 802.3 for Ethernet and 802.11 for Wi-Fi.

Layer 3: Network The Network layer determines the path of data packets based on different factors as defined by the protocol used. At this layer we see IP addressing for routing of data packets. This layer also includes routing protocols such as the Routing Information Protocol (RIP) and the Interior Gateway Routing Protocol (IGRP). This is the know-where-to-go layer.

Layer 4: Transport The Transport layer ensures the transport or sending of data is successful. This function can include error-checking operations as well as working to keep data messages in sequence. At this layer we find the Transmission Control Protocol (TCP) and the User Datagram Protocol (UDP).

Layer 5: Session The Session layer identifies established system sessions between different network entities. When you access a system remotely, for example, you are creating a session between your computer and the remote system. The Session layer monitors and controls such connections, allowing multiple, separate connections to different resources. Common use includes NetBIOS and RPC.

Layer 6: Presentation The Presentation layer provides a translation of data that is understandable by the next receiving layer. Traffic flow is presented in a format that can be consumed by the receiver and can optionally be encrypted with protocols such as Secure Sockets Layer (SSL).

Layer 7: Application The Application layer functions as a user platform in which the user and the software processes within the system can operate and access network resources. Applications and software suites that we use on a daily basis are under this layer. Common examples include protocols we interact with on a daily basis, such as FTP and HTTP.

Friday, July 28, 2017

jboss eap 7 standalone setup Database

This note is for example guide for adding MySql, Oracle and mariadb for jboss eap 7 standalone.

MySql

1. download Mysql jdbc from this URL
https://dev.mysql.com/downloads/connector/j/

2. then at jboss directory, create this path
<jboss>/modules/com/mysql/main

3. upload the jdbc into the main directory and create module.xml.
copy and paste below into module.xml
change the word in red color to be same name as your driver name

<?xml version="1.0" encoding="UTF-8"?>
<module xmlns="urn:jboss:module:1.0" name="com.mysql">
  <resources>
    <resource-root path="mysql-connector-java-5.1.43-bin.jar"/>
  </resources>
  <dependencies>
    <module name="javax.api"/>
    <module name="javax.transaction.api"/>
  </dependencies>
</module>

4. change permission of the newly created file and directory to jboss

5. start jboss service

6. go to jboss bin directory and connect to jboss-cli
# ./jboss-cli.sh -c --controller=<server-IP>

7. input this to add Mysql driver
/subsystem=datasources/jdbc-driver=mysql:add(driver-name=mysql,driver-module-name=com.mysql,driver-xa-datasource-class-name=com.mysql.jdbc.jdbc2.optional.MysqlXADataSource)

8. to edit the database connection details, i use its admin pages to add as it much more easy
at Browser, access to your admin pages by <server_ip>:9990
then follow the step below as screenshot

go to Configuration > Subsystems > Datasources > Non-Xa
and click add

Choose MySQL and click Next

Enter your JNDI name as below

go to Detected Driver and choose mysql

edit your connection URL according to your DB with the username and password

confirm details is correct and click Finish

Restart your jboss,
then back to admin > configuration again
then click your newly created Mysql and click test connection

you are done once test successful 


Oracle

1. download your oracle jdbc driver from this URL, choose the one match your DB version

2. create path for module/com/oracle/main

3. upload the driver to main folder and create module.xml
copy and paste below into module.xml
change the word in red color to be same name as your driver name

<module xmlns="urn:jboss:module:1.1" name="com.oracle">
  <resources>
    <resource-root path="ojdbc6.jar"/>
  </resources>
  <dependencies>
    <module name="javax.api"/>
    <module name="javax.transaction.api"/>
  </dependencies>
</module>

4. change ownership to jboss for newly create dir and file
# chown -R jboss;jboss module

5. start jboss and use jboss-cli to add the driver information
# ./jboss-cli.sh -c --controller=<server-IP>

6. copy paste below to setup the driver
/subsystem=datasources/jdbc-driver=oracle:add(driver-name=oracle,driver-module-name=com.oracle,driver-xa-datasource-class-name=oracle.jdbc.xa.client.OracleXADataSource)

7. to add DB details, go to admin site and add like Mysql example above. ( repeat step 8 for Mysql section)
just need to edit from mysql to oracle


MariaDB

1. download your oracle jdbc driver from this URL, choose the one match your DB version

2. create path for module/com/mariadb/main

3. upload the driver to main folder and create module.xml
copy and paste below into module.xml
change the word in red color to be same name as your driver name

<module xmlns="urn:jboss:module:1.1" name="com.mariadb">
    <resources>
        <resource-root path="mariadb-java-client-1.3.3.jar"/>
    </resources>
    <dependencies>
        <module name="javax.api"/>
        <module name="javax.transaction.api"/>
    </dependencies>
</module>


4. change ownership to jboss for newly create dir and file
# chown -R jboss;jboss module

5. start jboss and use jboss-cli to add the driver information
# ./jboss-cli.sh -c --controller=<server-IP>

4. copy and paste to add the driver information
/subsystem=datasources/jdbc-driver=mariadb:add(driver-name=mariadb,driver-module-name=com.mariadb,driver-xa-datasource-class-name=org.mariadb.jdbc.MariaDbDataSource)

5. to add DB details, go to admin site and add like Mysql example above. (repeat step 8 at Mysql section)
just need to edit from mysql to oracle


MsSql

1. download your oracle jdbc driver from this URL, choose the one match your DB version

2. create path for module/com/microsoft/main

3. upload the driver to main folder and create module.xml
copy and paste below into module.xml
change the word in red color to be same name as your driver name

<module xmlns="urn:jboss:module:1.1" name="com.microsoft">
    <resources>
        <resource-root path=".jar"/>
    </resources>
    <dependencies>
        <module name="javax.api"/>
        <module name="javax.transaction.api"/>
        <module name="javax.xml.bind.api"/>
    </dependencies>
</module>


4. change ownership to jboss for newly create dir and file
# chown -R jboss;jboss module

5. start jboss and use jboss-cli to add the driver information
# ./jboss-cli.sh -c --controller=<server-IP>

4. copy and paste to add the driver information
/subsystem=datasources/jdbc-driver=microsoft:add(driver-name=microsoft,driver-module-name=com.microsoft,driver-xa-datasource-class-name=com.microsoft.sqlserver.jdbc.SQLServerXADataSource)

5. to add DB details, go to admin site and add like Mysql example above. (repeat step 8 at Mysql section)
just need to edit from mysql to oracle

Friday, July 21, 2017

Jboss EAP 7 Standalone cluster - TCP

Tested environment
OS: Centos 7 / Rhel 7 (SELinux and firewall disabled )
Java: Oracle JDK 1.8
Jboss: Jboss EAP 7.0.0 (2016-05-10)

Started to try setup Jboss EAP 7 cluster using standalone mode. But fail to setup using their default config which using UDP multicast, so been googling and found working solution at RedHat portal which using TCP for it multicast.
below is the step i had taken to setup my Jboss EAP 7 Standalone cluster for 2 server

Please make sure you had setup 2 server before you start this as the cluster config needed to input both server IP

Oracle JDK 1.8

1. download your oracle jdk 1.8 from this URL
http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html

download the "jdk-8u141-linux-x64.rpm"

2. transfer to your server and install it
# yum localinstall jdk-8u141-linux-x64.rpm

3. confirm your java with this command
# java -version
java version "1.8.0_131"
Java(TM) SE Runtime Environment (build 1.8.0_131-b11)
Java HotSpot(TM) 64-Bit Server VM (build 25.131-b11, mixed mode)


JBOSS EAP 7 setup

1. download your jboss from this URL
https://developers.redhat.com/products/eap/download/
I use version 7.0.0 as currently that's the latest stable version.

2. transfer to your Centos 7 / RHEL 7 and unpack the package
# unzip jboss-eap-7.0.0.zip

3. move the folder to /opt
# mv jboss-eap-7.0 /opt/

4. Add a management user, you can skip this if you does not need it. But for me, it useful for me to monitoring and give to developer to deploy code and get log.
# cd /opt/jboss-eap-7.0/bin
( NOTE: since i only using it for testing and development use, i edit the password config so I do not require me to setup complicated password )
# vim add-user.properties
password.restriction=WARN
to
password.restriction=RELAX

# ./add-user.sh
What type of user do you wish to add?
 a) Management User (mgmt-users.properties)
 b) Application User (application-users.properties)
(a): a
Enter the details of the new user to add.
Using realm 'ManagementRealm' as discovered from the existing property files.
Username : jboss-admin
Password :
Re-enter Password :
What groups do you want this user to belong to? (Please enter a comma separated list, or leave blank for none)[  ]:
About to add user 'jboss-admin' for realm 'ManagementRealm'
Is this correct yes/no? yes
Added user 'jboss-admin' to file '/opt/jboss-eap-7.0/standalone/configuration/mgmt-users.properties'
Added user 'jboss-admin' to file '/opt/jboss-eap-7.0/domain/configuration/mgmt-users.properties'
Added user 'jboss-admin' with groups  to file '/opt/jboss-eap-7.0/standalone/configuration/mgmt-groups.properties'
Added user 'jboss-admin' with groups  to file '/opt/jboss-eap-7.0/domain/configuration/mgmt-groups.properties'
Is this new user going to be used for one AS process to connect to another AS process?
e.g. for a slave host controller connecting to the master or for a Remoting connection for server to server EJB calls.
yes/no? yes
To represent the user add the following to the server-identities definition <secret value="amJvc3MtYWRtaW4=" />

5. go to init.d folder and update jboss config
# cd init.d/
# vim jboss-eap.conf

## Location of JDK
 JAVA_HOME="/usr/java/default" 
## Location of JBoss EAP
 JBOSS_HOME="/opt/jboss-eap-7.0" 
## The username who should own the process.
 JBOSS_USER=jboss 
## The mode JBoss EAP should start, standalone or domain
 JBOSS_MODE=standalone 
## Configuration for standalone mode
 JBOSS_CONFIG=standalone-ha.xml

6. Edit the startup script to point to this config file
# vim jboss-eap-rhel.sh

# Load JBoss EAP init.d configuration.
if [ -z "$JBOSS_CONF" ]; then
        JBOSS_CONF="/opt/jboss-eap-7.0/bin/init.d/jboss-eap.conf"
fi

7. add user jboss since inside the config, we had set to run this as jboss user
# useradd jboss

8. change jboss ownership to jboss
# chown -R /opt/jboss-eap-7.0

9. try startup the jboss
# ./jboss-eap-rhel.sh start

Cluster setup

1. once the jboss is started, left it running as the next step needed it to implement the setting.
go to bin directory and create new file call tcp-cluster
# cd /opt/jboss-eap-7.0/bin
# touch tcp-cluster

2. open tcp-cluster file and pass this below into it.

batch
# Add the tcpping stack
/subsystem=jgroups/stack=tcpping:add
/subsystem=jgroups/stack=tcpping/transport=TCP:add(socket-binding=jgroups-tcp)
/subsystem=jgroups/stack=tcpping/protocol=TCPPING:add
# Set the properties for the TCPPING protocol
/subsystem=jgroups/stack=tcpping/protocol=TCPPING:write-attribute(name=properties,value={initial_hosts="HOST_A[7600],HOST_B[7600]",port_range=0,timeout=3000})
/subsystem=jgroups/stack=tcpping/protocol=MERGE3:add
/subsystem=jgroups/stack=tcpping/protocol=FD_SOCK:add(socket-binding=jgroups-tcp-fd)
/subsystem=jgroups/stack=tcpping/protocol=FD:add
/subsystem=jgroups/stack=tcpping/protocol=VERIFY_SUSPECT:add
/subsystem=jgroups/stack=tcpping/protocol=pbcast.NAKACK2:add
/subsystem=jgroups/stack=tcpping/protocol=UNICAST3:add
/subsystem=jgroups/stack=tcpping/protocol=pbcast.STABLE:add
/subsystem=jgroups/stack=tcpping/protocol=pbcast.GMS:add
/subsystem=jgroups/stack=tcpping/protocol=MFC:add
/subsystem=jgroups/stack=tcpping/protocol=FRAG2:add
# Set tcpping as the stack for the ee channel
/subsystem=jgroups/channel=ee:write-attribute(name=stack,value=tcpping)
run-batch
reload

Edit your host to your IP for both of your server (which in Red color font)

3. execute the script by using this command
# ./jboss-cli.sh --connect --file=tcp-cluster

4. stop your jboss service
# ./init.d/jboss-eap-rhel.sh stop

5. go to edit standalone-ha config and update it to listen to your IP instead of localhost
# cd /opt/jboss-eap-7.0/standalone/configuration/
# vim standalone-ha.xml

    <interfaces>
        <interface name="management">
            <inet-address value="${jboss.bind.address.management:192.168.95.132}"/>
        </interface>
        <interface name="public">
            <inet-address value="${jboss.bind.address:192.168.95.132}"/>
        </interface>
        <interface name="private">
            <inet-address value="${jboss.bind.address.private:192.168.95.132}"/>
        </interface>
    </interfaces>

6. you need to edit java_opt to give your node a name
# cd /opt/jboss-eap-7.0/bin/
# vim standalone.conf


if [ "x$JAVA_OPTS" = "x" ]; then
   JAVA_OPTS="-Xms1350m -Xmx1350m -XX:MetaspaceSize=96M -XX:MaxMetaspaceSize=256m -Djava.net.preferIPv4Stack=true"
   JAVA_OPTS="$JAVA_OPTS -Djboss.modules.system.pkgs=$JBOSS_MODULES_SYSTEM_PKGS -Djava.awt.headless=true -Djboss.node.name=node1"
else
   echo "JAVA_OPTS already set in environment; overriding default settings with values: $JAVA_OPTS"
fi

please use different name for your 2nd server

7. you can start your jboss and try access it using <server_IP>:8080

8. your cluster is done and for your war file, you need to code it to support cluster. at the end of this node, I will write testing section on how to make sure it is cluster and jsession is transfer to each other when it down.


Startup


for the startup, we will use back jboss initd script provided.
It located at /opt/jboss-eap-7.0/bin/init.d/jboss-eap-rhel.sh

1. go to systemd and create jboss.service
# cd /usr/lib/systemd/system
# vim jboss.service

2. paste this into it and save it

[Unit]
Description=Jboss EAP 7
After=syslog.target
After=network.target


[Service]
Type=forking
ExecStart=/opt/jboss-eap-7.0/bin/init.d/jboss-eap-rhel.sh start
ExecStop=/opt/jboss-eap-7.0/bin/init.d/jboss-eap-rhel.sh stop
TimeoutStartSec=300
TimeoutStopSec=300


[Install]
WantedBy=multi-user.target


3. enable jboss to start during boot
# systemctl enable jboss.service

4. start jboss service to verify it is working
# systemctl start jboss

Apache Web Setup

I going to use apache with mod_jk for my web + balancer

1. install apache and needed package
# yum install httpd httpd-devel gcc

2. download mod_jk and build it. You can get it from this URL
http://tomcat.apache.org/download-connectors.cgi
get the JK 1.2.42 Source Release tar.gz (e.g. Unix, Linux, Mac OS)

3. unpack it, configure, make
# tar -zxvf tomcat-connectors-1.2.42-src.tar.gz
# tomcat-connectors-1.2.42-src/native/
# find / -iname apxs
# ./configure --with-apxs=/usr/bin/apxs
# make
# make install

4. setup web config file
# cd /etc/httpd/conf.d/
# vim workers.properties


worker.list=worker1,node1,node2,status
#node name you using here need to be same in standalone.conf
worker.jkstatus.type=status 
#node1
worker.node1.port=8009
worker.node1.host=192.168.95.132
worker.node1.type=ajp13
worker.node1.lbfactor=1
worker.node1.ping_mode=A
#worker.node1.cachesize=10 
#node2
worker.node2.port=8009
worker.node2.host=192.168.95.135
worker.node2.type=ajp13
worker.node2.lbfactor=1
worker.node2.ping_mode=A
#worker.node2.cachesize=10 
# Load-balancing behaviour
worker.worker1.type=lb
worker.worker1.balance_workers=node1,node2
worker.worker1.sticky_session=1


# vim mod_jk.conf


LoadModule jk_module modules/mod_jk.so
<IfModule mod_jk.c>
JkWorkersFile /etc/httpd/conf.d/workers.properties
JkShmFile /var/log/httpd/mod_jk.shm
JkLogFile /var/log/httpd/mod_jk.log
JkLogLevel info,debug
JkLogStampFormat "[%a %b %d %H:%M:%S %Y] "

JkMount /* worker1
#mount this url, edit as neccessary
</IfModule>

5. save it and start apache service

Testing

By right, if you are using Exsi to host your server. You should see cluster member view inside the log during the jboss startup.
for mine, i only using Vmware workstation on my laptop and host 2 server. So there is nothing to be see on the log if do not have any War file with cluster setting deploy.
So do not freak out if your log do not show the cluster member.

here is the step taken to test my cluster is working

1. download this war file, which i get it from RedHat solutions
https://drive.google.com/uc?export=download&id=0B04R1MEwmWozVTRaS1VxNGtJU1E
Unzip the file.
Inside it, go to counter/dist, download the counter.war

2. deploy it to your both of your jboss. You can either use the management console to deploy it or put the war file to the deployment folder
(NOTE: once you deploy the war file to both server, you should be able to see the cluster member info show up in your log )

3. go to <server-1_IP>/counter in browser

4. refresh few times, and you should see the counter increasing

5. now stop server-1 jboss, when it done fully stop, even we are still using server-1 web but the backend should be redirected to server-2 jboss since we had stop server-1 jboss.

6. Try refresh the pages and you should see the counter is continue increase instead of get reset. this had prove the jsession has been pass to other member of the cluster when it get down.


Thursday, May 11, 2017

exsi patch

patch exsi package  -> https://esxi-patches.v-front.de/ESXi-6.0.0.html


[root@bs-lab02:~] esxcli software profile update -d https://hostupdate.vmware.com/software/VUM/PRODUCTION/main/vmw-depot-index.xml -p ESXi-6.
0.0-20160804001-standard
Update Result
   Message: The update completed successfully, but the system needs to be rebooted for the changes to be effective.
   Reboot Required: true
   VIBs Installed: VMware_bootbank_esx-base_6.0.0-2.43.4192238, VMware_bootbank_esx-ui_1.4.0-3959074, VMware_bootbank_misc-drivers_6.0.0-2.43.4192238, VMware_bootbank_net-vmxnet3_1.1.3.0-3vmw.600.2.43.4192238, VMware_bootbank_vsan_6.0.0-2.43.4097166, VMware_bootbank_vsanhealth_6.0.0-3000000.3.0.2.43.4064824, VMware_locker_tools-light_6.0.0-2.43.4192238
   VIBs Removed: VMware_bootbank_esx-base_6.0.0-2.34.3620759, VMware_bootbank_esx-ui_1.0.0-3617585, VMware_bootbank_misc-drivers_6.0.0-2.34.3620759, VMware_bootbank_net-vmxnet3_1.1.3.0-3vmw.600.2.34.3620759, VMware_bootbank_vsan_6.0.0-2.34.3563498, VMware_bootbank_vsanhealth_6.0.0-3000000.3.0.2.34.3544323
   VIBs Skipped: VMWARE_bootbank_mtip32xx-native_3.8.5-1vmw.600.0.0.2494585, VMware_bootbank_ata-pata-amd_0.3.10-3vmw.600.0.0.2494585, VMware_bootbank_ata-pata-atiixp_0.4.6-4vmw.600.0.0.2494585,

mount CD and use as repo

# mount -o loop /dev/sr0  /mnt

# cp /mnt/media.repo /etc/yum.repos.d/rhel7dvd.repo
# chmod 644 /etc/yum.repos.d/rhel7dvd.repo

sed notes

sed -ie 's/word1/word2/g' /testing

find word1 and replace it to word2 inside /testing file
-i option is used to edit in place on the file testing.
-e option indicates the expression/command to run, in this case s/.

Notes:
the / can be replace with anything as long no conflict with inside word
example

sed -ie 's:word1:word2:g' /testing

HaProxy

Environment: Centos 7
Haproxy version: 1.5.18
Installation
you can install by using this command
# yum install haproxy

Configure
the configuration file is located at /etc/haproxy/haproxy.cfg
open and edit the file
you need to define frontend and backend

frontend LB
  bind 0.0.0.0:80                       # bind to all network IP:port
  reqadd X-Forwarded-Proto:\ http
  default_backend LB                             # point to backend name LB

backend LB
  mode http
  balance roundrobin                               # Load balancing will work in round-robin process.
  option httpchk
  option  httpclose
  option forwardfor
  cookie SERVERID insert                  # Let the load-balancer set up a cookie for the session.          
  server svrv-trep-app01 172.20.101.115:80 cookie app01 check        # server 1
  server svrv-trep-app02 172.20.101.116:80 cookie app02 check       # server 2
  server backup-server 172.20.101.124:80 check backup              # if all server fail, traffic will go to this backup server



cookie app0x = this is so when client come back, it know which server to go back to.
but if it was new client, then it will set SERVERID=app01 into the header

if using application for session persistence
then replace SERVERID with JSESSIONID

the "check" is use to check if the server is alive or not

Enable Stats
edit 

  stats enable                                            # enable statistic pages
  stats hide-version                                
  stats uri /stats                                         # statistic pages at /stats
  stats realm Haproxy\ Statistics            
  stats auth username:password               # Credentials for HAProxy Statistic report page.

Enable log
1. edit rsyslog file
# vim /etc/rsyslog.conf
find and enable this

# Provides UDP syslog reception
$ModLoad imudp
$UDPServerRun 514

This will make the server listen to port 514 to collect log

2. since inside haproxy.conf, it already define this
log         127.0.0.1 local2

then we create a new file call haproxy.conf under /etc/rsyslog.d/
# vim /etc/rsyslog.d/haproxy.conf

and put this
local2.*     /var/log/haproxy.log

3. Then restart the rsyslog service
# systemctl restart rsyslog

Enable SSL

1. edit the haproxy.conf and add the httpd frontend

frontend LBS
  bind 0.0.0.0:443 ssl crt /etc/haproxy/test.pem      # listen to port 443, ssl crt is at /etc/haproxy/test.pem
  reqadd X-Forwarded-Proto:\ https
  default_backend LB                                              # go to backend name LB


so the connection will be like this
Public -- use https secure connection --> Haproxy -- use http --> backend server

2. if you want to enforce ssl, then add this to the backend

redirect scheme https if !{ ssl_fc }


so the final configuration will look something like this


frontend LB
  bind 0.0.0.0:80        
  reqadd X-Forwarded-Proto:\ http          
  default_backend LB                          

frontend LBS
  bind 172.20.101.128:443 ssl crt /etc/haproxy/test.pem
  reqadd X-Forwarded-Proto:\ https
  default_backend LB

backend LB
  mode http
  redirect scheme https if !{ ssl_fc }
  stats enable                                        
  stats hide-version                                
  stats uri /stats                                      
  stats realm Haproxy\ Statistics          
  stats auth username:password             
  balance roundrobin                            
  option httpchk
  option  httpclose
  option forwardfor
  cookie SERVERID insert                      
  server svrv-trep-app01 172.20.101.115:80 cookie app01 check      
  server svrv-trep-app02 172.20.101.116:80 cookie app02 check    
  server backup-server 172.20.101.124:80 check backup 


Microsite or redirrect certain sub path to other server

1. define the incoming domain name
        acl in_domain          hdr_dom(host) -i        www.testing.com

2. define backend server
backend testing_backend
        balance roundrobin
        option httpchk GET / HTTP/1.0
        server test-server 172.20.1.60:80 maxconn 200 check inter 5s
        server maintenance 203.208.240.126:80  backup
        timeout server 60s

3. define backend, if want to redirrect www.testing.com/camera to different server

        acl camera_r         path -i            /camera
        redirect location    /camera/           if testing_domain camera_r
        acl camera           path_beg -i        /camera/
        use_backend          testing_backend         if in_domain camera

== explain ==
1st line, is to define camera_r = /camera
2nd line, if fall on in_domain camera_r (mean www.testing.com/camera) then redirrect to www.testing.com/camera/
3rd line, is to define camera = /camera/
4th line, if fall on in_domain camera (www.testing.com/camera/) then redirrect to server testing_backend