Tag Archives: cli

Resetting Admin Password & Factory Reset a Nokia IP390 via CLI

So this is going to be quick post, as recently i had to decommission a Nokia IP390 Checkpoint firewall, where i had no details for the device 😀

Fortunately I was on site and had my trusty console cable! So this is going to be a reminder to myself on: How to do a password reset and factory reset of a Nokia IP390 via CLI

Let’s get cracking 🙂

Password Reset

Firstly, you need to have console access and the ability to reboot the device.

You will need to enter single user mode. Reboot the device and as it is going through it boot process, you will need to look for Type any character to enter command mode, once you see that hit enter and type boot -s to enter single user mode.

1,072,300,032 bytes of system memory tested OK
Starting bootmgr
Loading boot manager..
Boot manager loaded.
diskless platform
Entering autoboot mode.
Type any character to enter command mode.
BOOTMGR[1]> boot -s

You will be prompted with Enter pathname of shell or RETURN for sh: Just hit enter.

Enter pathname of shell or RETURN for sh:

With that you will be in Single-User Mode now, as you will have # prompt.

To reset the admin password, you need to run the overpw script: /etc/overpw

# /etc/overpw
    This program is used to set a temporary admin password when you have 
    lost the configured password.  You must have booted the machine into 
    single user mode to run it.  The configured password will be changed.
    Please change the temporary password as soon as you log on to your
    system through voyager.

Please enter password for user admin: 
Please re-enter password for confirmation: 
Continue? [n] y

You will be prompted with:

Admin password changed.  You may enter ^D to continue booting.  

As instructed hit ctrl + D and the booting process will continue. With that the admin password will be reset

Factory Reset

Now we have got admin access to the device, to do a factory reset is pretty noddy, to be honest. The IP390 is UNIX based cli, as shown by the single-user mode, firstly su into root:

Nokia[admin]# su root

Next, we need to change directory into the config folder:

Nokia[admin]# ls
bin     cdrom   dev     image   proc    tmp     var
bootmgr config  etc     opt     sbin    usr     web
Nokia[admin]# cd config

Delete all files the active files:

Nokia[admin]# ls
active  db
Nokia[admin]# rm active
Nokia[admin]# ls

Once all the files have been deleted, all that is needed is to reboot the device for the change to take affect:

Nokia[admin]# reboot

With that Bob’s your uncle, Sally’s your aunty and you have a decommissioned Nokia IP390 😀

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Configuring TACACS+ Server on Ubuntu 14.04LTS

It’s all change in the office so far this year, which is quite good as I’m involved in more projects, and who doesn’t enjoy a few projects 😉

The latest thing I was asked to look into was to create a new TACACS+ server as our current server on a HP Proliant BL460c G1 Blade is going to be decommissioned so we need to give it a new home! It was decided that it should be virtualized as there isn’t a need to have a physical server for something that can be slimmed down dramatically. With that being said this post will go over how to configure a TACACS+ server and configure TACACS+ authentication on a Juniper device.

TACACS+ is an improvement on its first version TACACS, as TACACS+ is an entirely new protocol and is not compatible with its predecessors, TACACS and XTACACS. TACACS+ uses TCP. Since TACACS+ uses the authentication, authorisation, and accounting (AAA) architecture, these separate components of the protocol can be segregated and handled on separate servers. TACACS+ allows you to set granular access policies for users and groups, commands, location, subnet, or even device type. The TACACS+ protocol also provides detailed logging of users and what commands have been run on specific devices. In addition, the protocol can run on either Windows or UNIX/Linux.

Although TACACS+ was developed by Cisco Systems, it is actually an open standard as defined by RFC1482 and has been incorporated into a number of different vendors including Alcatel/Lucent, Arbor, Brocade/Foundry, Cisco/Linksys, Extreme, HP/3Com, Huawei, IBM, Juniper/Netscreen, Netgear and any others.

The setup I had for testing was a simple one; I had 2 EXSi Ubuntu 14.04LTS hosts, one as the TACACS+ server with the second being used as Jump-box to access a Juniper SRX220 that will be configured for TACACS authentication.

With all that talk out of the way, let’s get cracking 🙂

You will run sudo/root privileges

Server Configuration

Fortunately, with the newer version of Ubuntu, from apt-get repository you can easily download the tacacs+ package it will also install libtacacs+1

[email protected]:~$ sudo apt-get install tacacs+
[sudo] password for marquk01: 
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following extra packages will be installed:
The following NEW packages will be installed
  libtacacs+1 tacacs+

Having installed the package now we can run the command ps -ef | grep tac_plus and it will show us the location of the configuration file and if the process is running:

[email protected]:~$ ps -ef | grep tac_plus
root      1220     1  0 11:37 ?        00:00:00 /usr/sbin/tac_plus -C /etc/tacacs+/tac_plus.conf
marquk01 22730  2682  0 13:55 pts/0    00:00:00 grep --color=auto tac_plus

As the process is running there’s a few useful binary files that are important to know, these can be seen when you type tac and hit TAB.

[email protected]:~$ tac
tac  tac_plus  tac_pwd

The important files are tac_plus and tac_pwd:

  • tac_plus is the TACACS+ daemon. You can run daemon via the cli
  • tac_pwd is used to generate a Data Encryption Standard (DES) or Message-Digest 5 (MD5) hash from clear text. DES is the defualt, to generate a MD5 hash you need to add -m flag.

We will need to configure the tac_plus.conf file, but firstly we will need to back-up the original file to refer back to if there is any issues

[email protected]:~$ sudo cp /etc/tacacs+/tac_plus.conf /etc/tacacs+/tac_plus.conf.old

I’ll explain from top-down of what my file looks like. The default file has more parameters than I used, as my file doesn’t need too much complexity. My example will also show you how to configure the basis Accounting, Secret Key, Users and Groups. Logically when I look at the layout of the file as I have, it doesn’t make sense… However, all the information is there soooooo it doesn’t matter :p lol


Firstly we’ll need to set the file that the accounting information will be written to. By default this is /var/log/tac_plus.acct, however you can have this file where you like if you don’t want you use the default file and path.

You have to create this file yourself. This can be done by running the command sudo touch /var/log/tac_plus.acct

# Created by Henry-Nicolas Tourneur([email protected])
# See man(5) tac_plus.conf for more details

# Define where to log accounting data, this is the default.

accounting file = /var/log/tac_plus.acct

Secret Key

The Server and Client need to have a matching key so the AAA packets can be encrypted. This key can be anything you wish however, if you’re going to have a key with white-space, key-words, or special characters, you’ll need to use quotation marks

# This is the key that clients have to use to access Tacacs+

key = testing123


You’ll need to define the users that will have access to the device. Each user needs to be associated to a group and have their password defined. The password has to be set as either a MD5 or DES hash. By using tac_pwd use can get your hashed output:

[email protected]:~$ tac_pwd
Password to be encrypted: lab123

There is an additional stanza service = junos-exec that defines an additional group. This is Juniper specific and I’ll explain this later. I created two users kmarquis; will have permission to do anything and second usertest; that will only have Read-Only access. Both have the same password. Usernames ARE case sensitive.

# We also can define local users and specify a file where data is stored.
# That file may be filled using tac_pwd
user = kmarquis {
    name = "Keeran Marquis"
    member = admin
    login = des kBeC6JDjU8icY
		service = junos-exec {
			local-user-name = remote-admin

user = test {
    name = "Test User"
    member = read-only
    login =  des kBeC6JDjU8icY
        service = junos-exec {
            local-user-name = remote-read-only


As you can guess, groups are where you define the level of access and what commands will be used by the group. The commands, for my example, are used to define actions that are largely accepted by most vendors with the expectation of Juniper (from my knowledge but correct me if I’m wrong), although I wont be confirming the configuration works in this post. I have checked with a Cisco device and they worked as expected.

We have a few parameters that are important remember:

  • default service: defines the default permission that the user will have. By default, if this statement isn’t used or left blank, it’s denied. Meaning that each permitted command users of this group will have to be listed. If you want the default permission to allow, then the statement permit is needed
  • service: define services which the group is authorised to execute, these could be commands that the group is authorised to execute. Authorisation must be configured on both the client and the daemon to operate correctly.
  • cmd: This is where you list a command and set an action, it will be either be a permit or deny. Additionally by having the .* this means that any command after the first word is affected. i.e my example below, all show commands will be permitted

In my example I have two groups, admin and read-only, the admin group will have full access permitted and the read-only group, as the name suggests, will have read-only access and will be denied from any configuration, clear or restart commands.

# We can also specify rules valid per group of users.
group = admin {
	default service = permit
	service = exec {
		priv-lvl = 15

group = read-only {
	service = exec {
		priv-lvl = 15
	cmd = show {
		permit .*
	cmd = write {
		permit term
	cmd = dir {
		permit .*
	cmd = admin {
		permit .*
	cmd = terminal {
		permit .*
	cmd = more {
		permit .*
	cmd = exit {
		permit .*
	cmd = logout {
		permit .*

My completed tac_plus file can be seen here.

For more in-depth detail and additional parameters that can be configured in this file, you can find them via the man pages using the command man tac_plus or online Ubuntu tac_plus Manual Documentation

Once you’re happy with everything you can run service tacacs_plus check to make sure the syntax is correct and if you get any errors you will need to restart the daemon using service tacacs_plus restart

TACACS+ Daemon Commands
Additional commands that will be useful to remember:

service tacacs_plus check
service tacacs_plus status
service tacacs_plus stop
service tacacs_plus start
service tacacs_plus restart

With that we have a TACACS+ server configured 🙂

Before getting into the configuration of the SRX, I stated earlier that there’s a Juniper Specific stanza in tac_plus.conf file. When authenticating users against a TACACS+ server on juniper devices and you’ll need to apply Juniper Networks Vendor-Specific TACACS+ Attributes.

These attributes can be either:

  1. Specified in the tac_plus.conf file by using regular expressions to list all the commands that the user has permitted or denied. A user will need to be created on the device with that user being referred under the local-user-name statement. The stanza would look something:
    service = junos-exec {
    	local-user-name = xxx
    	allow-commands =  .*
    	allow-configurations = .*
    	deny-commands = 
    	deny-configuration = 
    	user-permissions = 
  2. Configure a class that has states all the permitted or denied permissions, this class will be linked to a user. Both need to be configured on the device. Once this has been created you’ll need to refer, said user, under the local-user-name

The Junos OS retrieves these attributes through an authorization request of the TACACS+ server after authenticating a user. For my example, I went with the latter. Now we’ll jump onto the SRX220 and get that sorted with TACACS+ AAA configuration.

Juniper Configuration

Firstly, you will have to set the TACACS+ server with its secret key. For standard practice and force of habit, I have set the single connection and forced the source-address of the SRX. By using the single connection statement, this means that instead of multiple TCP sessions connecting to the device from a server, a single session is maintained between them. In addition, for best practice an authentication order should be set so that if there was an issue or loss of connectivity to the TACACS+ server, you’ll be able to fall back to locally defined users.

authentication-order [ tacplus password ];
tacplus-server { {
        secret "$9$SszyMXVb2aGiYgi.fzCAIEcyvWX7-w24"; ## SECRET-DATA

With the TACACS+ server we’re able log different events that take place on the device and get those commands sent to the server. From my experience the accounting events that you would most want logged are logins, configuration changes and interactive commands. This is set under system accounting stanza

accounting {
    events [ login change-log interactive-commands ];
    destination {

Next, under the system login stanza, you need to create a class that has a list of permission available to the user(s) that are going to be associated to it. The user(s) are what are used in the tac_plus.conf file. In my example I created two classes, one with all permission super-user-local and the other user with read-only and basic troubleshooting options (ie ping, traceroute, telnet etc) read-only-user-local. These associated this classes with 2 users remote-admin and remote-read-only

login {
    class read-only-user-local {
        permissions [ network view view-configuration ];
    class super-user-local {            
        permissions all;
    user remote {
        full-name "TACACS User";
        uid 2001;
        class super-user-local;
    user remote-read-only {
        full-name "TACACS read-only user";
        uid 2002;
        class read-only-user-local;
You can learn more about the different permissions flags available here on Juniper TechLibrary


To confirm the configuration is working as expected, I will ssh onto the SRX220 with both the admin user kmarquis and the read-only user test. With both users, I will log in and try to configure the description This is a test on a random port. As you can see below I had no problem with user kmarquis. However, when I logged in with the test user I wasn’t able to enter the configuration mode as the permission wasn’t granted, and for that user the command isn’t even recognized. I ran a show command and you will see that none of the passwords are shown. Again this is due to the permission level granted.

Admin AccessRead Only Access
[email protected]:~$ ssh -l kmarquis
--- JUNOS 12.1X47-D30.4 built 2015-11-13 14:16:02 UTC
[email protected]> configure 
Entering configuration mode
[email protected]# set interfaces ge-0/0/5 description "This is a test" 

[email protected]# commit and-quit 

[email protected]>
[email protected]:~$ ssh -l test
--- JUNOS 12.1X47-D30.4 built 2015-11-13 14:16:02 UTC
[email protected]> configure
unknown command.

[email protected]> show configuration 
## Last commit: 2016-02-01 12:56:23 UTC by kmarquis
version 12.1X47-D30.4;
system {
    host-name v6-testing;
    authentication-order [ tacplus password ];
    root-authentication {
        encrypted-password /* SECRET-DATA */; ## SECRET-DATA

If we check the /var/log/tac_plus.acct file we’ll be able to see all the permitted commands by each user. This is additional confirmation that the users have successfully authenticated against the TACACS+ server and their related permissions authorised to the device.

Feb  1 12:55:38      kmarquis        ttyp0      start   task_id=1       service=shell   process*mgd[38808]      cmd=login
Feb  1 12:55:41      kmarquis        ttyp0      stop    task_id=2       service=shell   process*mgd[38808]      cmd=show configuration 
Feb  1 12:55:44      kmarquis        ttyp0      stop    task_id=3       service=shell   process*mgd[38808]      cmd=edit 
Feb  1 12:56:01      kmarquis        ttyp0      stop    task_id=4       service=shell   process*mgd[38808]      cmd=set: [interfaces ge-0/0/5 de$
Feb  1 12:56:01      kmarquis        ttyp0      stop    task_id=5       service=shell   process*mgd[38808]      cmd=set interfaces ge-0/0/5 desc$
Feb  1 12:56:05      kmarquis        ttyp0      stop    task_id=6       service=shell   process*mgd[38808]      cmd=commit and-quit 
Feb  1 12:56:27      kmarquis        ttyp0      stop    task_id=7       service=shell   process*mgd[38808]      cmd=exit 
Feb  1 12:56:27      kmarquis        ttyp0      stop    task_id=1       service=shell   elapsed_time=49 process*mgd[38808]      cmd=logout
Feb  1 12:56:34      test    ttyp0      start   task_id=1       service=shell   process*mgd[38845]      cmd=login
Feb  1 12:56:44      test    ttyp0      stop    task_id=2       service=shell   process*mgd[38845]      cmd=show configuration 
Feb  1 12:56:53      test    ttyp0      stop    task_id=3       service=shell   process*mgd[38845]      cmd=show system uptime 
Feb  1 12:56:56      test    ttyp0      stop    task_id=4       service=shell   process*mgd[38845]      cmd=exit 
Feb  1 12:56:56      test    ttyp0      stop    task_id=1       service=shell   elapsed_time=22 process*mgd[38845]      cmd=logout

And with that all, we have a fully configured and working AAA TACACS+ server 🙂

Extra Treat 🙂
I have included the set commands below:

set system tacplus-server secret "$9$SszyMXVb2aGiYgi.fzCAIEcyvWX7-w24"
set system tacplus-server single-connection
set system tacplus-server source-address

set system authentication-order tacplus
set system authentication-order password

set system accounting events login
set system accounting events change-log
set system accounting events interactive-commands
set system accounting destination tacplus

set system login class super-user-local permissions all
set system login class read-only-user-local permissions network
set system login class read-only-user-local permissions view
set system login class read-only-user-local permissions view-configuration

set system login user remote-read-only full-name "TACACS read-only user"
set system login user remote-read-only uid 2005
set system login user remote-read-only class read-only-user-local
set system login user remote-admin full-name "TACACS User"
set system login user remote-admin uid 2006
set system login user remote-admin class super-user-local
Extra Extra Treat 😀
P.S. If you want to see what configuration could be used on a Cisco device I have added it below. Although I didn’t test it myself, this is the config we have in production and it works :p

aaa new-model
aaa authentication login default group tacacs+ local enable
aaa authorization exec default group tacacs+ local none 
aaa authorization commands 0 default group tacacs+ local none 
aaa authorization commands 1 default group tacacs+ local none 
aaa authorization commands 15 default group tacacs+ local none 
aaa accounting exec default start-stop group tacacs+
aaa accounting commands 0 default start-stop group tacacs+
aaa accounting commands 1 default start-stop group tacacs+
aaa accounting commands 15 default start-stop group tacacs+
aaa session-id common


Configure TACACS+ Ubuntu 14.04LTS
TACACS+ Accounting
TACACS+ Authenication
TACACS+ Advantages

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IPv6 and Junos – Stateful Auto-configuration with DHCPv6

As part of my on-going IPv6 testing, I was asked to look into stateful auto-configuration for devices and host using DHCPv6. I had already looked into Stateless Address Auto configuration and looked into another method of providing stateful auto-configuration using a Dual Stacked DHCP server. This time I’ll be looking into how this could be done using Juniper hardware, to be specific Juniper SRX series routers. If you haven’t used DHCP before my other DHCP related post gave an explanation on what DHCP is and how DHCPv6 communications work slightly different to DHCPv4. With that in mind, I won’t be going over what DHCP is again, but instead I’ll be going straight into the good stuff!

Lets get cracking 😀

For this test I had simple topology; I used a Juniper SRX220 as the DHCP server and a single ESXi Ubuntu 14.04LTS hosts connected on port ge-0/0/0 as the client.

Firstly, with the SRX, I had to enabled IPv6 flow mode. By default, IPv6 IS NOT enabled. You enable IPv6 flow mode by running the command set security forwarding-options family inet6 mode flow-based, once committed you’ll need to reboot the device for the change to take effect. When the SRX is finished booting you can confirm IPv6 flows will be able to be permitted by using show security flow status:

[email protected]> show security flow status 
  Flow forwarding mode:
    Inet forwarding mode: flow based
    Inet6 forwarding mode: flow based
    MPLS forwarding mode: drop
    ISO forwarding mode: drop
  Flow trace status
    Flow tracing status: off
  Flow session distribution
    Distribution mode: RR-based
  Flow ipsec performance acceleration: off
  Flow packet ordering
    Ordering mode: Hardware

Now that we know we can actually get stateful IPv6 flows traversing the SRX, we can start with enabling the SRX as a DHCPv6 server.

Under the system services dhcp-local-server stanza, we will need to confirm that we’ll be using DHCPv6 and set the interface(s) that will be requesting addresses. Additionally there are a few optional commands. For my example I’ve set the max limit of DHCP clients to 100 by using the interface-client-limit statement, and by default there are no limits on amount of clients that can request an address.

[email protected]# show system services 
dhcp-local-server {
    dhcpv6 {
        overrides {
            interface-client-limit 100;
        group v6 {
            interface vlan.100;

Next, under the access address-assignment stanza is where we’ll set the prefix pool that will be advertised to host, and your IP range. In addition, within this stanza you’re able to set other DHCP details such as lease time, grace period and dns-server under dhcp-attributes. The attributes are optional however they should be looked into and configured according to your own requirements.

[email protected]# show access   
address-assignment {
    pool v6 {
        family inet6 {
            prefix 2001:192:168:1::/64;
            range dhcpv6-range {
                low 2001:192:168:1::200/128;
                high 2001:192:168:1::299/128;
            dhcp-attributes {
                maximum-lease-time 120;
                grace-period 3600;

We need to set the SRX so that the router advertises our IPv6 prefix on the correct interface, and in addition, by adding the statement managed-configuration, the router will be both stateful (DHCP) and stateless (SLAAC) address assignments. Finally, in order for the DHCPv6 server to allow DHCPv6 requests, a security policy is needed to enable DHCPv6 traffic.

ProtocolsSecurity Zone
[email protected]# show protocols 
router-advertisement {
    interface vlan.100 {
        prefix 2001:192:168:1::/64;
[email protected]# show security zone security-zone internal {
    interfaces {
        vlan.100 {
            host-inbound-traffic {
                system-services {

With SRX configured, we can now check the client side to make sure it’s enabled for DHCP. On the client, we have to set its interface to listening for DHCP packets. For IPv6 we’ll need to set the interface to DHCP under /etc/network/interfaces.

[email protected]:~$ cat /etc/network/interfaces
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).
auto eth1
iface eth1 inet dhcp

# This is an autoconfigured IPv6 interface
iface eth0 inet6 auto

auto eth1
iface eth1 inet6 dhcp

Now that we have both the SRX and the client configured, we can bring it all together and run some tests!

Verification Testing

On the client, we’ll request an IP address from the SRX by running dhclient eth1 -6 -v and can confirm that an address has been successful assigned by doing an ifconfig

Requesting an addressifconfig eth1
[email protected]:~$ sudo dhclient eth1 -6 -v 
Internet Systems Consortium DHCP Client 4.2.4
Copyright 2004-2012 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/

Bound to *:546
Listening on Socket/eth1
Sending on   Socket/eth1
PRC: Soliciting for leases (INIT).
XMT: Forming Solicit, 0 ms elapsed.
XMT:  X-- IA_NA 29:4f:26:c5
XMT:  | X-- Request renew in  +3600
XMT:  | X-- Request rebind in +5400
XMT:  | X-- Request address 2001:192:168:1::111.
XMT:  | | X-- Request preferred in +7200
XMT:  | | X-- Request valid in     +10800
XMT:  | X-- Request address 2001:192:168:1::200.
XMT:  | | X-- Request preferred in +7200
XMT:  | | X-- Request valid in     +10800
XMT: Solicit on eth1, interval 1060ms.
RCV: Advertise message on eth1 from fe80::120e:7eff:fe4e:2e88.
RCV:  X-- IA_NA 29:4f:26:c5
RCV:  | X-- starts 1452250973
RCV:  | X-- t1 - renew  +60
RCV:  | X-- t2 - rebind +96
RCV:  | X-- [Options]
RCV:  | | X-- IAADDR 2001:192:168:1::200
RCV:  | | | X-- Preferred lifetime 120.
RCV:  | | | X-- Max lifetime 120.
RCV:  X-- Server ID: 00:02:00:00:05:83:43:46:34:37:31:33:41:4b:30:32:38
RCV:  Advertisement recorded.
PRC: Selecting best advertised lease.
PRC: Considering best lease.
PRC:  X-- Initial candidate 00:02:00:00:05:83:43:46:34:37:31:33:41:4b:30:32 (s: 153, p: 0).
XMT: Forming Request, 0 ms elapsed.
XMT:  X-- IA_NA 29:4f:26:c5
XMT:  | X-- Requested renew  +3600
XMT:  | X-- Requested rebind +5400
XMT:  | | X-- IAADDR 2001:192:168:1::200
XMT:  | | | X-- Preferred lifetime +7200
XMT:  | | | X-- Max lifetime +7500
XMT:  V IA_NA appended.
XMT: Request on eth1, interval 930ms.
RCV: Reply message on eth1 from fe80::120e:7eff:fe4e:2e88.
RCV:  X-- IA_NA 29:4f:26:c5
RCV:  | X-- starts 1452250974
RCV:  | X-- t1 - renew  +60
RCV:  | X-- t2 - rebind +96
RCV:  | X-- [Options]
RCV:  | | X-- IAADDR 2001:192:168:1::200
RCV:  | | | X-- Preferred lifetime 120.
RCV:  | | | X-- Max lifetime 120.
RCV:  X-- Server ID: 00:02:00:00:05:83:43:46:34:37:31:33:41:4b:30:32:38
PRC: Bound to lease 00:02:00:00:05:83:43:46:34:37:31:33:41:4b:30:32:38:31.
[email protected]:~$ ifconfig eth1
eth1      Link encap:Ethernet  HWaddr 00:0c:29:4f:26:c5  
          inet6 addr: fe80::20c:29ff:fe4f:26c5/64 Scope:Link
          inet6 addr: 2001:192:168:1::200/64 Scope:Global
          RX packets:12342 errors:0 dropped:0 overruns:0 frame:0
          TX packets:11980 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:4052626 (4.0 MB)  TX bytes:3303461 (3.3 MB)

Having confirmed that an IP address from DHCP pool has been assigned on the client, we can now look on SRX to see what has happened there!

Firstly, I checked to see if I could see the session flow from the client to SRX by running show security flow session. As the output below shows, as per RFC3315, DHCPv6 communications are done on UDP ports 546 (clients) and 547 (server/relay) and via link-local addresses.

[email protected]> show security flow session       
Session ID: 1, Policy name: self-traffic-policy/1, Timeout: 1800, Valid
  In: -->;tcp, If: ge-0/0/7.0, Pkts: 5631, Bytes: 416401
  Out: -->;tcp, If: .local..0, Pkts: 3109, Bytes: 389005

Session ID: 9, Policy name: self-traffic-policy/1, Timeout: 54, Valid
  In: fe80::120e:7eff:fe4e:2e88/547 --> fe80::20c:29ff:fe4f:26c5/546;udp, If: .local..0, Pkts: 2, Bytes: 288
  Out: fe80::20c:29ff:fe4f:26c5/546 --> fe80::120e:7eff:fe4e:2e88/547;udp, If: vlan.100, Pkts: 0, Bytes: 0
Total sessions: 2

We only get two show commands with a DHCP server, whether it’s v4 or v6, show dhcpv6 server binding and show dhcpv6 server statistics.

  • show dhcpv6 server binding provides details on the address that has been assigned to a client, which including; MAC address, Prefix, Lease time, current state and interface.
  • show dhcpv6 server statistics, as the name suggests, provides figures on sent and receive messages between the server and clients.
DHCPv6 BindingsDHCPv6 Statistics
[email protected]> show dhcpv6 server binding        
Prefix                  Session Id  Expires  State    Interface    Client DUID
2001:192:168:1::200/128 2           74       BOUND    vlan.100     LL_TIME0x1-0x1ddd0462-00:0c:29:4f:26:c5
[email protected]> show dhcpv6 server statistics 
Dhcpv6 Packets dropped:
    Total               0

Messages received:
    DHCPV6_DECLINE             0
    DHCPV6_SOLICIT             1
    DHCPV6_RELEASE             0
    DHCPV6_REQUEST             1
    DHCPV6_CONFIRM             0
    DHCPV6_RENEW               0
    DHCPV6_REBIND              0
    DHCPV6_RELAY_FORW          0
    DHCPV6_RELAY_REPL          0

Messages sent:
    DHCPV6_ADVERTISE           1
    DHCPV6_REPLY               1
    DHCPV6_RECONFIGURE         0
    DHCPV6_RELAY_REPL          0

For completeness, I had the client release the assigned address to check the statistics, just to make sure I did see an increment change.

Releasing Assigned AddressDHCPv6 Statistics
[email protected]:~$ sudo dhclient -6 -v -r eth1
Internet Systems Consortium DHCP Client 4.2.4
Copyright 2004-2012 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/

Bound to *:546
Listening on Socket/eth1
Sending on   Socket/eth1
XMT: Forming Release, 0 ms elapsed.
XMT:  X-- IA_NA 29:4f:26:c5
XMT:  | X-- Release Address 2001:192:168:1::200
XMT:  V IA_NA appended.
XMT: Release on eth1, interval 1070ms.
RCV: Reply message on eth1 from fe80::120e:7eff:fe4e:2e88.
RCV:  X-- Server ID: 00:02:00:00:05:83:43:46:34:37:31:33:41:4b:30:32:38
[email protected]> show dhcpv6 server statistics    
Dhcpv6 Packets dropped:
    Total               0

Messages received:
    DHCPV6_DECLINE             0
    DHCPV6_SOLICIT             1
    DHCPV6_RELEASE             1
    DHCPV6_REQUEST             1
    DHCPV6_CONFIRM             0
    DHCPV6_RENEW               1
    DHCPV6_REBIND              0
    DHCPV6_RELAY_FORW          0
    DHCPV6_RELAY_REPL          0

Messages sent:
    DHCPV6_ADVERTISE           1
    DHCPV6_REPLY               3
    DHCPV6_RECONFIGURE         0
    DHCPV6_RELAY_REPL          0

And with that a DHCPv6 Server has been configured using a Juniper SRX series router!

I’ve included a useful show command and the set commands that I used in my example below 🙂

Operational CommandsSet Commands
show security flow session
show dhcpv6 server binding
show dhcpv6 server statistics
clear dhcpv6 server binding
clear dhcpv6 server statistics
set security forwarding-options family inet6 mode flow-based

set system services dhcp-local-server dhcpv6 overrides interface-client-limit 200
set system services dhcp-local-server dhcpv6 group v6 interface vlan.100

set protocols router-advertisement interface vlan.100 prefix 2001:192:168:1::/64

set access address-assignment pool v6 family inet6 prefix 2001:192:168:1::/64
set access address-assignment pool v6 family inet6 range dhcpv6-range low 2001:192:168:1::200/128
set access address-assignment pool v6 family inet6 range dhcpv6-range high 2001:192:168:1::299/128
set access address-assignment pool v6 family inet6 dhcp-attributes maximum-lease-time 120
set access address-assignment pool v6 family inet6 dhcp-attributes grace-period 3600

set security zones security-zone internal interfaces vlan.100 host-inbound-traffic system-services dhcpv6

More in-depth detailed information can be found on Juniper’s TechLibrary pages

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Configuring NTP Server on Ubuntu

As part of a few changes happening I’ve been asked to look into how difficult would it be to configure our own local NTP server. From looking at very useful Ubuntu Man Pages and finding great articles on The Geek Stuff (one of my favourites sites) and Blogging Dragon, it appears that it’s more straightforward than I expected! Soooo this post will note down how to install and configure a NTP Server.

Network Time Protocol (NTP) is a network protocol for clock synchronization between servers, network devices and desktops. NTP is defined in RFC5905 and is described as:

Network Time Protocol version 4 (NTPv4), which is widely used to synchronize system clocks among a set of distributed timeservers and clients…. The NTP subnet model includes a number of widely accessible primary time servers synchronized by wire or radio to national standards. The purpose of the NTP protocol is to convey timekeeping information from these primary servers to secondary time servers and clients via both private networks and the public Internet.

For this test, I’m using ESXi Ubuntu 14.04LTS host as the local NTP server and will be configuring both a Juniper SRX220 and another ESXi Ubuntu 14.04LTS host as a NTP clients. The local NTP server’s IP address is

You will need root and/or sudo privileges

With all the background done, let’s get cracking 😀

As always, when getting anything from Ubuntu’s apt-get repository we’ll need to make sure to run update; to get all the newest version of packages currently installed and run dist-upgrade; to ensure the most important packages are updated as it has a “smart” conflict resolution system.

sudo apt-get update
sudo apt-get dist-upgrade

Having ensured the server’s packages are up to date, we can install the ntp and ntpdate packages by using apt-get install ntp ntpdate

sudo apt-get install ntp ntpdate

Before making any changes we need to make sure that the default time zone to Universal Time Coordinated (UTC). This is because UTC is regarded as the primary time standard by which the world regulates clocks and time. You can check/change the default time zone by running the command dpkg-reconfigure tzdata. You will be prompted to these screens where you can select the time zone: Screen #1 and Screen #2.

Once the time zone has been set, you will get the output below confirming the Time Zone:

[email protected]:~$ sudo dpkg-reconfigure tzdata

Current default time zone: 'Etc/UTC'
Local time is now:      Mon Jan 11 14:56:57 UTC 2016.
Universal Time is now:  Mon Jan 11 14:56:57 UTC 2016.

Next create a backup of the ntp.conf file

sudo cp /etc/ntp.conf /etc/ntp.conf.old

Use a text editor (I prefer nano) to open up the ntp.conf file and find the following lines below:

# Use servers from the NTP Pool Project. Approved by Ubuntu Technical Board
# on 2011-02-08 (LP: #104525). See http://www.pool.ntp.org/join.html for
# more information.
server 0.ubuntu.pool.ntp.org
server 1.ubuntu.pool.ntp.org
server 2.ubuntu.pool.ntp.org
server 3.ubuntu.pool.ntp.org

You can comment them out, delete, keep or replace the lines. The lines are specifying multiple servers to act as a timeserver, which is helpful when one of the timeservers fail. You can use regional pool ntp severs from ntp.org’s Regional Pools. In my example, as I live in the UK, I’ve used the regional pool of servers closest to the UK

server 0.uk.pool.ntp.org iburst dynamic
server 1.uk.pool.ntp.org iburst dynamic
server 2.uk.pool.ntp.org iburst dynamic
server 3.uk.pool.ntp.org iburst dynamic

The sytax iburst and dynamic are optional commands but can be useful to have set, depending on your environment.

  • iburst: After every poll a burst of eight packets is sent instead of one. When the server is not responding, packets are sent at 16 seconds intervals. When the server responds, packets are sent every 2 seconds. This means that after reboot or restart ntp synchronizations are established quicker.
  • dynamic: This option tells NTP it can try a configured server again later if it’s unavailable at some point, which can be useful when the server doesn’t always have Internet connectivity.
You can see my full example ntp.conf file here

Having saved and close the updated ntp.conf file, we’ll need to restart the daemon running service ntp restart

[email protected]:~$ sudo service ntp restart
 * Stopping NTP server ntpd                 [ OK ] 
 * Starting NTP server ntpd                 [ OK ]

After restarting the daemon, the server will take around 10-15 minutes for NTP to synchronize with the timeservers and it will automatically set the system clock. By using the command ntpq -p we’ll be able to check the status of the NTP servers that we are synchronized with

[email protected]:~$  ntpq -p
     remote           refid      st t when poll reach   delay   offset  jitter
 time.rdg.uk.as4    2 u   21   64    3    3.138    0.047   0.506
 resntp-a-vip.lo     3 u   22   64    3    1.723    2.038   0.526
 2a03:b0c0:1:d0:      3 u   19   64    3    2.870    1.632   0.337
 neon.trippett.o    2 u   26   64    3    2.928    1.863   0.473
 golem.canonical   2 u   24   64    3    9.211    3.418   0.387

The table below explains the different parameters from the ntpq -p output:

Parameters Function
Remote Specifics the hostname of the timeserver
Refid This is a 32-bit code identifying the particular reference clock.
St (Stratus) This indicates your physical GPS closeness to the timeserver. Anything under 3 is seen as good
When Number of Seconds passed since the last poll or time check
Poll This is the minimum interval between transmitted messages, in seconds as a power of two. For instance, a value of six indicates a minimum interval of 64 seconds.
Reach How well a clock can maintain a constant frequency.
Delay Provides the capability to launch a message to arrive at the reference clock at a specified time. Relative to a selected reference clock.
Offset The time difference between two clocks, relative to a selected reference clock. Represents the amount to adjust the local clock to bring it into correspondence with the reference clock.
Jitter Short-term variations in Frequency with components greater than 10 Hz. The estimated time error of the system clock measured as an exponential average of RMS time differences.

You will be able start, stop, restart and/or check ntp status by using these commands

service ntp status
service ntp start
service ntp stop
service ntp restart

And with that we have a NTP server configured!

Enabling NTP Client

For testing, I configured a Juniper SRX220 to be the NTP client. It’s quite straightforward to enable ntp on a SRX; you’ll need to set and commit the commands to below and with that you will have NTP enabled. Simple Right! 🙂

set system ntp server prefer
set system ntp server version 4

For verification of NTP on the SRX we can run show ntp associations, show ntp status and show system uptime

show ntp associationsshow system uptimeshow ntp status
[email protected]> show ntp associations no-resolve 
     remote           refid      st t when poll reach   delay   offset  marquk01
*     3 -    8   64    1    1.849    2.498   0.160
[email protected]> show system uptime 
Current time: 2016-01-11 10:15:27 UTC
System booted: 2016-01-08 10:02:36 UTC (3d 00:12 ago)
Protocols started: 2016-01-08 10:05:13 UTC (3d 00:10 ago)
Last configured: 2016-01-11 10:13:34 UTC (00:01:53 ago) by marquk01
10:15AM  up 3 days, 13 mins, 2 users, load averages: 0.05, 0.11, 0.04
[email protected]> show ntp status                     
status=0664 leap_none, sync_ntp, 6 events, event_peer/strat_chg,
version="ntpd 4.2.0-a Fri Nov 13 15:40:48 UTC 2015 (1)",
processor="octeon", system="JUNOS12.1X47-D30.4", leap=00, stratum=4,
precision=-17, rootdelay=13.781, rootdispersion=2.340, peer=31708,
reftime=da3dff68.c47f84ec  Mon, Jan 11 2016 10:16:08.767, poll=6,
clock=da3dff6b.8ee12a6f  Mon, Jan 11 2016 10:16:11.558, state=3,
offset=0.000, frequency=0.000, jitter=0.213, stability=0.000

And on the Ubuntu host, it’s exactly the same as I described above, but in the /etc/ntp.conf file you’ll need to set the server as your local NTP server

# Use servers from the NTP Pool Project. Approved by Ubuntu Technical Board
# on 2011-02-08 (LP: #104525). See http://www.pool.ntp.org/join.html for
# more information.
#server 0.ubuntu.pool.ntp.org
#server 1.ubuntu.pool.ntp.org
#server 2.ubuntu.pool.ntp.org
#server 3.ubuntu.pool.ntp.org

server prefer iburst dynamic

We can then run ntpq -p to check the ntp server is the local server!

[email protected]:~$ ntpq -p
     remote           refid      st t when poll reach   delay   offset  jitter
*  3 u   28   64    1    0.454    0.380   0.315

For more in-depth detailed information on how to use NTP pools see ntp.org and the Ubuntu Man page for more detail on ntp.conf file.

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How to access HP’s ILO remote console via SSH

This will be a quick reminder for myself on how you can remote console via SSH on HP Blade Server and Standalone Servers 🙂

1. Connect to the ilo using SSH, Whether its with PuTTy (Windows) or Terminal (MacOSX or Linux) with the super or admin user and pass.
ssh [email protected]_address

[[email protected] ~]$ ssh -l Administrator
[email protected]'s password: 
User:Administrator logged-in to ILO----n.(
iLO 2 Standard Blade Edition 2.25 at 16:36:26 Apr 14 2014
Server Name: vMX-Bay1
Server Power: On


2. Having entered onto the server now via ilo, you will be able to connect to the remote console by either using the commands TEXTCONS or VSP


TEXTCONS is short for text console. When I used TEXTCONS, I got this output Monitor is in graphics mode or an unsupported text mode.


Starting text console.
Press 'ESC (' to return to the CLI Session.


Monitor is in graphics mode or an unsupported text mode.

From some quick reading it appears that some OS do not supported access using TEXTCONS, which is no help for me, however this is one way!


VSP is Virtual Serial Port. As the name suggests it is the virtual port, that is the same as, if you connected a serial cable onto the server. This worked a treat for me, so I am happy now 😀

hpiLO-> VSP

Starting virtual serial port.
Press 'ESC (' to return to the CLI Session.

hpiLO-> Virtual Serial Port active: IO=0x03F8 INT=4

Ubuntu 14.04.2 LTS lab13 ttyS0

lab13 login: 

Job done 🙂

Other CLI commands available:

HP CLI Commands:

POWER    : Control server power.
UID      : Control Unit-ID light.
NMI      : Generate an NMI.
VM       : Virtual media commands.
VSP      : Invoke virtual serial port.
VSP LOG  : Invoke virtual serial port data logging.
TEXTCONS : Invoke Remote Text Console on supported platforms.
It is important to note as well, there some OS that don’t support TEXTCONS or VSP. I had installed ESXi 6 on the blade and although it didn’t give me an error I wasn’t able to get any output. So this can be a little hit and miss at times. Its something I probably should look into but when i have some time in the future!
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