This short example illustrates basic VLAN operation. Examining VLANs in a large-scale installation can show the full benefits of VLANs. Consider that this is a small portion of a large corporate headquarters with 5,000 devices connected in a 20 building campus.

   

   

   

Omegle is shutting down notorious video chat service as scrutiny grows.

The anonymous service that paired strangers together is shutting down after 14 years amid increasingly strict online safety regulations, with an admission that it was used to commit ‘heinous crimes.’

Even if you never used Omegle, you’d probably heard about its sketchy reputation.

Omegle, a popular video chat service that randomly connects users with strangers, has shut down after 14 years amid misuse of the platform and increased scrutiny by online safety regulators. In a lengthy statement announcing the closure, website founder Leif K Brooks said that operating Omegle is “no longer sustainable, financially nor psychologically,” and that fighting to prevent it from being misused is “simply too much.” While the website remains live to host Brook’s statement, its anonymous video chat function is no longer accessible.

Omegle gained a reputation as a breeding ground for sexual abuse of minors, leading to a prominent lawsuit in which the website was accused of pairing an 11-year-old girl with a sexual predator. The decision to shut down the platform comes at a time when global lawmakers are introducing strict online safety regulations to prevent child sexual exploitation, such as the UK’s Online Safety Bill.

“There can be no honest accounting of Omegle without acknowledging that some people misused it, including to commit unspeakably heinous crimes,” said Brooks. “From the bottom of my heart, thank you to everyone who used Omegle for positive purposes, and to everyone who contributed to the site’s success in any way. I’m so sorry I couldn’t keep fighting for you.”

Key computer systems at hospitals and clinics in several states have yet to be turned back on more than two weeks after a cyberattack forced some emergency room shutdowns and ambulance diversions

Key computer systems at hospitals and clinics in several states have yet to come back online more than two weeks after a cyberattack that forced some emergency room shutdowns and ambulance diversions.

Progress is being made “to recover critical systems and restore their integrity,” Prospect Medical Holdings said in a Friday statement. But the company, which runs 16 hospitals and dozens of other medical facilities in California, Connecticut, Pennsylvania, Rhode Island and Texas, could not say when operations might return to normal.

“We do not yet have a definitive timeline for how long it will be before all of our systems are restored,” spokeswoman Nina Kruse said in a text message. “The forensic investigation is still underway and we are working closely with law enforcement officials."

The recovery process can often take weeks, with hospitals in the meantime reverting to paper systems and people to monitor equipment, run records between departments and do other tasks usually handled electronically, John Riggi, the American Hospital Association’s national advisor for cybersecurity and risk, said at the time of the breach.

The attack, which was announced Aug. 3, had all the hallmarks of extortive ransomware but officials would neither confirm nor deny this. In such attacks, criminals steal sensitive data from targeted networks, activate encryption malware that paralyzes them and demand ransoms.

The FBI advises victims not to pay ransoms as there is no guarantee the stolen data won’t eventually be sold on dark web criminal forums. Paying ransoms also encourages the criminals and finances attacks, Riggi said.

As a result of the attack, some elective surgeries, outpatient appointments, blood drives and other services are still postponed.

Eastern Connecticut Health Network, which includes Rockville General and Manchester Memorial hospitals as well as a number of clinics and primary care providers, was running Friday on a temporary phone system.

Waterbury Hospital has been using paper records in place of computer files since the attack but is no longer diverting trauma and stroke patients to other facilities, spokeswoman Lauresha Xhihani told the Republican-American newspaper.

“PMH physicians, nurses, and staff are trained to provide care when our electronic systems are not available,” Kruse wrote. “Delivering safe, quality care is our most important priority.”

Globally, the health care industry was the hardest-hit by cyberattacks in the year ending in March, according to IBM’s annual report on data breaches. For the 13th straight year it reported the most expensive breaches, averaging $11 million each. Next was the financial sector at $5.9 million.

Health care providers are a common target for criminal extortionists because they have sensitive patient data, including histories, payment information, and even critical research data, Riggi said.

eSIM is slowly gaining traction with top phone brands and should make it easier to switch from one carrier to another—or to add a second line to your phone without heading to a carrier store.

You have almost certainly seen a SIM card: a thumbnail-sized chip that sits somewhere in your mobile phone, telling it which carrier and what phone number you use. Now, those SIMs are going digital (or "e") and moving your information from a static but removable chip to a re-programmable, embedded chip. Not everyone is happy about it. Here's why.

A SIM card is a "subscriber identity module." Required in all GSM, LTE, and 5G devices, it's a chip that holds your customer ID and details of how your phone can connect to its mobile network. SIMs started out around the size of a postage stamp, but have been getting smaller over the years as device makers reclaim more space inside their gadgets for other electronics. An eSIM takes the circuitry of a SIM, solders it directly to a device's board, and makes it remotely re-programmable through software.

The original drive toward eSIM came in part from the "Internet of Things" industry. Being tiny, and not requiring extra room for a slot, eSIMs can be built into devices like drones, wearable s, sensors, and location trackers, where size is of the essence. They can also be soldered into industrial equipment where a SIM card may not be easily accessible. Because they can reprogrammed remotely, it means eSIMs can be managed in bulk. So, say, a company that runs 50,000 vending machines can switch its service plan or provider with the touch of a button from its headquarters.

   

This site https://www.gogetssl.com/ offers what seems to be any type of SSL certificate for very low prices. A standard domain ssl certificate cost as little as $24 per year. This cert is usually approx. $100. 

Some of their pricing details;

GeoTrustQuickSSL Premium (Flex)
Domain
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GeoTrustQuickSSL Premium SAN (Flex)
Domain
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GeoTrustQuickSSL Premium Wildcard
Domain
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GoGetSSL90-day Trial SSL
Domain
5 minutes
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GoGetSSLDomain SSL
Domain
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GoGetSSLMulti-Domain SSL (Flex)
Domain
5 minutes
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GoGetSSLPublic IP SAN
Domain
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GoGetSSLSecure Domain SSL (Flex)
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5 minutes
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GoGetSSLWildcard SSL
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RapidSSLStandard certificate
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RapidSSLWildcard certificate
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SectigoPositiveSSL Multi Wildcard
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[url=https://www.gogetssl.com/dv-ssl/positivessl-wildcard/]Details

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Hello,
I had an issue recently with this very forum. I thought I would share my experience to help others facing similar situations, and illustrate the importance of good regular backups.
This site is hosted at Infinityfree.com which provides up to 3 sites (hosted websites) with "full service" setups. MySQL, Ftp, DNS, custom domains etc. All 100% with no gimmicks or add placements. It is as good as any paid web hosting service & when combined with Cloudflare DNS hosting is a very robust and secure configuration. All free too. Okay enough about that, onto the issue.

I went to access my forum after not being on for a few days, and to my surprise it was down! The Mybb error message was "Error 44" paraphrasing a little, its also said "could not locate or load MySQL extensions.  There is extensive documentation about this issue which all leads to changing the config.php file in Mybb to list the SQL server type as MySQLi or MySQL if the other type is listed. When I made this change from MySQL to MySQLi it caused the site to attempt to load, but had several coding errors appear on the screen.  At the time I did not really understand why the coding errors were there, I assumed MySQLi is not the right setting for my site and the problem must be related to the extensions not loading as the error (44) suggested.
I went to the hosting providers KB and immediately saw that there were issues with the hosting server I was being hosted on. So I thought that my issue was related to the hosting server issues. It was not. Within hours the hosting issues were resolved but by forum was still down with the same errors.
I tried restoring the forum from a recent backup. Once this was complete the forum still had the same error (44)... how odd!
I posted a question on the hosting providers KB asking if any major changes were recently done on the hosting server. The answer was YES. They had changed with PHP from version 7.?? to the most current version 8.??.

THE WORK
I backed up the MySQL DB and all files.
I deleted the forum and deleted the MySQL database using the hosting providers provided tools, Phpmyadmin. I created a brand new empty Database with the same name as the previous one.  I then installed the latest version of Mybb... A new vanilla installation. This worked. When I examined the database type detail in config.php, it in fact was MySQLi. *The installed version of myBB was not the same version as the one installed.

RESTORING TO A NEW INSTALLATION OF MYBB.
Since I would be restoring my SQL database to the new installation, I went back to the hosting provider and again deleted the database and created a new one with the same name.
Using their tool Phpmyadmin I restored the MySQL backup from a the newly created backup. This restored all of the most important data. The users, the forums, the posts, and themes.
What it did not restore was all of the physical file dependencies, like custom images, forum post images,  custom avatars, and plugins. All the files are very easily restore able from the latest file backup.  What is not super simple is the Plugins (the likely source of most of the problems when the PHP version changed on the server).
Since the plugins were not  restored, their configuration settings need to be removed. Go to AdminCP, then Configuration. From the left side pane, choose Settings. On the center page choose Modify Settings. Choose the plugins which no longer exist and choose Options, then Delete settings Group.
Lastly, download and install new compatible plugins.

Routing protocols are the rules that determine how routers communicate and exchange information about the paths and status of a network. Choosing the best routing protocol for your network depends on several factors, such as the size, topology, scalability, security, and performance of your network. In this post you will learn about the main types of routing protocols, their advantages and disadvantages, and how to evaluate them for your network needs.

Static vs Dynamic
Static routing protocols are manually configured by the network administrator and do not change unless the administrator updates them. Dynamic routing protocols are automatically updated by the routers based on the network conditions and topology changes. Static routing protocols are simple, fast, and secure, but they are not scalable, adaptable, or fault-tolerant. Dynamic routing protocols are scalable, adaptable, and fault-tolerant, but they are more complex, slower, and less secure than static routing protocols.

Distance Vector vs Link State
Distance vector protocols are based on the distance and direction of the destination network from the source router. They use hop count as the metric to determine the best path. Link state protocols are based on the status and cost of each link in the network. They use bandwidth, delay, load, or reliability to determine the best path. Distance vector routing is easy to implement and uses less resources, but is prone to routing loops, slow convergence, and inaccurate information. Link state routing protocols are more efficient and accurate, but they require more resources and processing power.

Interior vs Exterior
Interior routing protocols are used within a single autonomous system (AS), which is a group of routers under the same administrative control. Exterior routing protocols are used between different autonomous systems. Interior routing protocols are designed to optimize the routing within the AS, while exterior routing protocols are designed to facilitate the routing between the ASes. Interior routing protocols include RIP, EIGRP, OSPF, and IS-IS. Examples of exterior routing protocols include BGP and EGP.

Hybrid and Advanced
Hybrid routing protocols combine the features of distance vector and link state routing protocols. They use both distance and link information to determine the best path. They also use techniques such as triggered updates, partial updates, and route summarization to improve routing efficiency and scalability. Examples of hybrid routing protocols are EIGRP and BGP. Advanced routing protocols are designed to address specific challenges or requirements of modern networks, such as multicast, mobile, wireless, or IPv6 networks. They use special algorithms or mechanisms to support these features. Advanced routing protocols include DVMRP, PIM, OLSR, AODV, and RIPng.

Evaluation Criteria
When selecting the best routing protocol for your network, evaluate them based on criteria like compatibility, scalability, flexibility, security, overhead, and convergence. The routing protocol should be compatible with your hardware and software and able to handle growth without sacrificing performance or reliability. Additionally, it should be able to adapt to changes in your network topology and traffic patterns while protecting your network from unauthorized access. And it should minimize the amount of bandwidth, memory, and CPU resources it consumes for routing operations and reach a consistent state quickly after a change or failure. By comparing different types of routing protocols based on these criteria, you can choose the one that best meets your network goals and constraints.

The SRX series of firewalls operate in two command line modes 

CLI Modes

If you log in to the device as the root user, you enter the UNIX shell, which is indicated by the percent sign (%) as the prompt. To access the Junos CLI, enter the cli command at the shell prompt:

root% cli
user@host>

The JUNOS CLI two modes:
Operational mode–This mode displays the current status of the device. In operational mode, you enter commands to monitor and troubleshoot Junos Software and devices and network connectivity.
Configuration mode–A Junos device configuration is stored as a hierarchy of statements. In configuration mode, you enter these statements to define all properties of Junos Software, including interfaces, general routing information, routing protocols, flow-based security features, user access, and system and hardware properties.
Operational Mode

After logging in, you enter operational mode, which is indicated by the right angle bracket (>):

user@host>
Configuration Mode

From operational mode, use the configure command to enter configuration mode, which is indicated by the pound sign (#):

user@host> configure
[edit]
user@host#
To exit configuration mode and go back to operational mode, enter exit at the prompt:

user@host# exit
user@host>

Commands
Hostname and domain
# set system host-name test-host1
# set system domain-name juniper.net

NTP Server
# set system ntp server 10.10.10.100
# set system time-zone Asia/Tokyo

SNMP
# set snmp community public authorization read-only
# set snmp trap-group trap targets 10.10.10.200

_____________________________________________________________________________________

Show Configuration
Description `
-candidate configuration
> show configuration
> show configuration | display set
> show configuration | display set | no-more
> show configuration | display set | match XXXX
> show configuration security policies |display set
# show
# show | display set
# show | display set |no-more
# show | display set |match XXXX

Show configuration
- Active configuration
> file show /config/juniper.conf.gz
> show system rollback 0 ← active configuration
> show system rollback 1 ← 1 old
> file list /config
> file list /var/db/config

Set Configuration
Description Command
> configure
# load override terminal ← 'Ctrl D' is stop
# show | compare
# show | compare rollback 1
# commit check
# commit
# rollback ? ← check rollback date
# rollback 0 ← active configuration (If you don't commit, please rollback 0)
# rollback 1 ← old configuration

You must commit after rollback.

diff rollback configurations >show system rollback NUMBER compare NUMBER
>show system rollback 17 compare 16

# set system max-configuration-rollbacks 49
  (Max 49)
# run set cli screen-length 0
# commit confirmed ← automatically rollback if not confirmed after 10 minutes
# commit confirmed 5 ← automatically rollback if not confirmed after 5 minutes
you can ''commit' if you want to not rollback.

Configuration Flow
Configuration with set commands
#ssh  [email protected]

> configure      <- configuration mode

configuration
# show | display set <- check configuration
# show | compare  <- diff configuration
# commit check    <- check configuration
# commit          <- commit configuration. If you want to cancel this configuration, You can use "rollback 0" command.
# exit
> exit

Configuration with load set terminal
#ssh  [email protected]

# load set terminal
(abbr)
Ctrl + D

Step by Step Configuration with edit command
#ssh  [email protected]
> configure
# edit XXXXXXX    <- edit is like cd of linux.
# edit XXXXXXX
# up
# top
# edit XXXXXX
# show | display set
# set XXXX
# delete XXXX
# show | compare
# commit check
# commit
# exit            <- you need 'exit' command.
> exit
# edit XXXXXXX
# up
# top
# edit XXXXXX
# show | display set
# set XXXX
# delete XXXX
# show | compare
# commit check
# commit
# exit            <- you need 'exit' command.
> exit

Backup
Backup to Local Home Directory
Backup to '/cf/var/home/USER/FILENAME.conf'

> save FILENAME.conf

Backup to Remote Host
> show configuration | display set | save ftp://[email protected]/test-fw_30102013.txt
> show configuration | display set | save [email protected]:/home/config/test00-fw/tes00-fw_20120714.txt

> show configuration | display set | save ftp://USER:[email protected]/tes00-fw_20120714.txt

Restore
Operation Command
# load replace filename
# load factory-default

_________________________________________________________________________________
Operation Command
show zone > show security zones
# run show security zones

show default application 
# show groups junos-defaults applications
# show groups junos-defaults applications | display set | match XXXX
# show groups junos-defaults applications | hold XXXX

show policies hit count > show security policies hit-count
Clear policies hit count > clear security policies hit-count

Create Security Zone
root> configure
root# set security zones security-zone Trust interfaces reth0.0
root# set security zones security-zone Unrust interfaces reth1.0
root# show | compare
root# commit check
root# commit

Add Policy
create address-book and attach address-book to zone
# set security zones security-zone TRUST address-book address NW1 192.168.10.0/24
or
# set security address-book TRUST-NW address NW1 192.168.10.0/24
# set security address-book TRUST-NW attach zone TRUST

set security zones security-zone untrust address-book address test-01 xx.xx.xx.xx/32
set security zones security-zone untrust address-book address test-02 xx.xx.xx.xx/32
set security zones security-zone untrust address-book address-set test address test-01
set security zones security-zone untrust address-book address-set test address test-02

create application
# set applications application test9999 protocol tcp
# set applications application test9999 source-port 0-65535
# set applications application test9999 destination-port 9999

create policy
# set security zones security-zone DMZ address-book address test-server1 100.100.100.11/32
# set security policies from-zone untrust to-zone DMZ policy 030102013 match source-address any
# set security policies from-zone untrust to-zone DMZ policy 030102013 match destination-address test-server1
# set security policies from-zone untrust to-zone DMZ policy 030102013 match application junos-http junos-https
# set security policies from-zone untrust to-zone DMZ policy 030102013 then permit
# set security policies from-zone untrust to-zone DMZ policy 030102013 then log session-init
# edit security policies from-zone UNTRUST to-zone TRUST
# set policy UNTRUST2TRUST match source-address any
# set policy UNTRUST2TRUST match destination-address NW1
# set policy UNTRUST2TRUST match application junos-https junos-http
# set policy UNTRUST2TRUST then permit
# set policy UNTRUST2TRUST then count
# show
# edit security policies from-zone UNTRUST to-zone TRUST policy UNTRUST2TRUST
# set match source-address any
# set match destination-address NW1
# set match application junos-https junos-http
# set then permit
# set then count
# show

Change Policy Order
# insert security policies from-zone untrust to-zone DMZ  policy XXXX before XXXXX
# edit security policies from-zone untrust to-zone DMZ
# insert policy 10 before policy 6

Edit Policy
add smtp
# set security policies from-zone untrust to-zone DMZ policy 03102013 match application junos-smtp

remove https
# delete security policies from-zone untrust to-zone DMZ policy 03102013 match application junos-https

Delete Policy
# delete security policies from-zone untrust to-zone DMZ policy 03102013

Check Session & Clear Session
> show security flow session summary
> show security flow session
> show security flow session source-prefix x.x.x.x
> clear security flow session all
> show security flow session source-prefix x.x.x.x destination-prefix x.x.x.x
> clear security flow session source-prefix x.x.x.x
> show security flow session
> show security flow session source-prefix x.x.x.x
> clear security flow session all
> show security flow session source-prefix x.x.x.x destination-prefix x.x.x.x
> clear security flow session source-prefix x.x.x.x

Check Interfaces
Confirm whether the interface is Up or Down

> show interfaces terse

Check Interface Configuration
show interfaces command show Speed and negotiation.

> show interfaces ge-3/0/2
# show interfaces ge-0/0/1 | display set

Check Duplex and Speed
>show interfaces ge-0/0/1 media

IP address configuration
# set interfaces fe-0/0/1 unit 0 family inet address 192.168.1.1/24
# delete interfaces fe-0/0/1 unit 0 family inet address 192.168.1.1/24

Enable/Disable(like cisco's no shutdown/shutdown)
# set interfaces fe-0/0/1 disable
# delete interfaces fe-0/0/1 disable

unnumberd interface
unnumberd interface don't have ip address.

# set interfaces fe-0/0/1 unit 0 family inet

negotiation configuration
# set interfaces ge-0/0/1 ether-options auto-negotiation
# set interfaces ge-0/0/2 ether-options no-auto-negotiation
# set interfaces ge-0/0/2 ether-options speed 100m
# set interfaces ge-0/0/2 ether-options link-mode full-duplex

Permit ICMP ping with SRX
# set security zones security-zone untrust interfaces ge-0/0/1 host-inbound-traffic system-services ping

Clear interfaces statistics
> clear interfaces statistics

show policy >show security policies
> show configuration security policies |display set
#show | display set | no-more | match policy
# run show security policies
# run show security policies from ZONE to ZONE

show default application
# show groups junos-defaults applications
# show groups junos-defaults applications | display set | match XXXX
# show groups junos-defaults applications | hold XXXX

show policies hit count > show security policies hit-count
Clear policies hit count> clear security policies hit-count

root# commit

Active, Inactive Policy
# edit security policies from-zone untrust to-zone DMZ policy 10
# inactive
# active

ARP Table
Check ARP Table
> show arp
> show arp no-resolve  <- don't use dns

Clear ARP Table
> clear arp  <- clear all arp table
> clear arp hostname xx.xx.xx.xx

Mac Address Table
Check Mac Address Table
>show ethernet-switching table

Some vital information and configuration steps the Juniper SRX Firewall.

What is a flow session?
How can we interpret a flow session entry?
How can we open a standard port/application on SRX and do destination NAT?
How can we open a non-standard port and do destination NAT?
How can we do proxy-arp?

In this post, we will use the same topology like previous post but I have added three new devices in this new topology so that I can show source/destination nat and proxy arp.

What is a flow session?
Juniper SRX is a stateful firewall hence box doesn’t forward an IP packet and forgets it. It has to remember which IP packets it has received and which packets it is expecting. It isn’t exactly like this but for the sake of simplicity let’s assume like this now. So what does a session look like on an SRX firewall. In order to show this from PC1 device, I telnet to TCP port 80 of www.example.com host which is outside my test network and see how the flow session looks like on our SRX firewall.

TCP 80 connection is established towards the host 93.184.216.34

pc1>telnet www.example.com 80
Trying 93.184.216.34...
Connected to www.example.com.
Escape character is '^]'.
Now let’s see how this session looks like on our firewall

root@srx220> show security flow session destination-port 80
Session ID: 109, Policy name: allow-internal-clients/4, Timeout: 294, Valid
  In: 192.168.239.3/47715 --> 93.184.216.34/80;tcp, If: ge-0/0/1.0, Pkts: 2, Bytes: 112
  Out: 93.184.216.34/80 --> 192.168.100.38/20201;tcp, If: ge-0/0/0.0, Pkts: 1, Bytes: 60
Total sessions: 1
As you can see, we can display sessions by “show security flow session” command and by giving more options e.g destination-port you can filter session table.

How can we interpret a flow session entry?
Now let’s drill down this single flow session entry line by line.

Line 1

109 : Each session is given a session identifier by the firewall, here 109
allow-internal-clients/4 : Security which exactly matches this specific traffic and number 4 is the policy index.
294 : When a session is created it starts with default timeout and counts down to zero as long as no packet is seen. If it reaches 0 session is removed
Line 2

192.168.239.3/47715 : Source IP address/Port of the source host which created the session
93.184.216.34/80;tcp : Destination IP address/Port of the destination host and the transport layer protocol which is tcp here
ge-0/0/1.0 : The ingress interface of the packet
Pkts: 2, Bytes: 112 Number of packets and Bytes received on this direction
Line 3
A flow session has two wings and this one is the wing on the reverse direction.

93.184.216.34/80 : This is the same as our destination address
192.168.100.38/20201 : This is the address to which 93.184.216.34 replies back but it is different than our source IP address 192.168.239.3 since we are doing source NAT and port translation
ge-0/0/0.0 : Ingress interface of the return packets
Pkts: 1, Bytes: 60 : IP packet and Bytes received from the destination
How can we open a default/standard port/application on SRX and do destination NAT?
In the topology, we have a Web server and we would like to allow public HTTP service i.e anyone who types http://192.168.100.38 on their browser from Internet will be redirected to our internal web server i.e we will create a destination NAT rule and a security policy allowing this HTTP traffic.

First thing we should go to configuration mode

root@srx220> configure                                     
Entering configuration mode
Then we can paste the following commands to configure destination NAT

Destination NAT

set security nat destination pool webserver-internal address 192.168.239.10/32
set security nat destination rule-set internal-servers from zone internet
set security nat destination rule-set internal-servers rule webserver match destination-address 192.168.100.38/32
set security nat destination rule-set internal-servers rule webserver match destination-port 80
set security nat destination rule-set internal-servers rule webserver then destination-nat pool webserver-internal
Note: In order to forward traffic to the internal server, a pool is required

Security Policy
If you don’t permit the HTTP traffic in a security policy, destination NAT has no use.
On this setup I am moving from zone specific address groups to global addresses for which I am moving my old address book to global level and I am adding new address entry for webserver.

delete security zones security-zone internal address-book address network_239
set security address-book global address network_239 192.168.239.0/24
set security address-book global address webserver 192.168.239.10/32
Now we can create the security policy.

set security policies from-zone internet to-zone internal policy allow-web-service match source-address any
set security policies from-zone internet to-zone internal policy allow-web-service match destination-address webserver
set security policies from-zone internet to-zone internal policy allow-web-service match application junos-http
set security policies from-zone internet to-zone internal policy allow-web-service then permit
Note: On SRX, default applications are prefixed by junos- as you can see for junos-http application.

Finally commit your changes. Now we telnet to the IP 192.168.100.38 from outside network (10.100.100.10) and check the session table.

root@srx220> show security flow session destination-port 80
Session ID: 147, Policy name: allow-web-service/5, Timeout: 286, Valid
  In: 10.100.100.10/36120 --> 192.168.100.38/80;tcp, If: ge-0/0/0.0, Pkts: 3, Bytes: 164
  Out: 192.168.239.10/80 --> 10.100.100.10/36120;tcp, If: ge-0/0/1.0, Pkts: 2, Bytes: 120
Total sessions: 1
As you can see request for 192.168.100.38:80 is translated to 192.168.239.10:80 by SRX.

How can we open a non-standard port and do destination NAT?
Now we have a different requirement. There is an SMTP server which is listening on port default port 25 but we somehow want everyone to access this host on port 2025 instead of the default port. Now we will configure this scenario.

First Address book entry

set security address-book global address smtpserver 192.168.239.11
set security nat destination pool smtpserver-internal address 192.168.239.11/32
set security nat destination pool smtpserver-internal address port 25
set security nat destination rule-set internal-servers rule smtpserver match destination-address 192.168.100.38/32
set security nat destination rule-set internal-servers rule smtpserver match destination-port 2025
set security nat destination rule-set internal-servers rule smtpserver then destination-nat pool smtpserver-internal
Note: Pay attention that pool we created is for port 25 but actual port match is for 2025

Now security policy

set security policies from-zone internet to-zone internal policy allow-smtp-service match source-address any
set security policies from-zone internet to-zone internal policy allow-smtp-service match destination-address smtpserver
set security policies from-zone internet to-zone internal policy allow-smtp-service match application junos-smtp
set security policies from-zone internet to-zone internal policy allow-smtp-service then permit
Note: You may be asking why do we use junos-smtp application which has port 25 instead of an application which has destination port 2025. The reason is that security policy processing is done after destination is processed hence when security policy does the match, port is already translated to 25 from 2025.

For example, if you were to redirect(port nat) 2025 port to another non-standard port e.g 2000 on this smtp server then you would have to create an application e.g named custom-smtp and permit this application on this policy.

set applications application custom-smtp protocol tcp
set applications application custom-smtp destination-port 2025
But this isn’t what we are configuring now. We just redirect outside 2025 port to internal 25 port.

Now we telnet from our Internet host

root@vHost2:~# vhost INTERNET1
INTERNET1>telnet 192.168.100.38 2025
Trying 192.168.100.38...
Connected to 192.168.100.38.
Escape character is '^]'.
220 vHost2 ESMTP Postfix (Debian/GNU)
Heyyy, we have got the smtp response on non-standard port 2025. Let’s check the flow session.

root@srx220> show security flow session destination-port 25     
Session ID: 151, Policy name: allow-smtp-service/6, Timeout: 1784, Valid
  In: 10.100.100.10/56967 --> 192.168.100.38/2025;tcp, If: ge-0/0/0.0, Pkts: 3, Bytes: 164
  Out: 192.168.239.11/25 --> 10.100.100.10/56967;tcp, If: ge-0/0/1.0, Pkts: 2, Bytes: 151
Total sessions: 1
Yes, port 2025 is translated to 25 as it can be seen in the flow session too.

You can also check the translation hits by the following command to see if the NAT rule is really being hit or not.

root@srx220> show security nat destination rule smtpserver

Destination NAT rule: smtpserver          Rule-set: internal-servers
  Rule-Id                    : 2 
  Rule position              : 2
  From zone                  : internet
    Destination addresses    : 192.168.100.38  - 192.168.100.38
    Destination port        : 2025            - 2025
  Action                    : smtpserver-internal
  Translation hits          : 1    <---Here we can see the translation hits.
    Successful sessions      : 1
    Failed sessions          : 0
  Number of sessions        : 1

How can we do proxy-arp?
According to our topology, we have only one WAN IP assigned to the external interface which is 192.168.100.38 but our ISP has given us a /24 block from which now we also would like to use IP address 192.168.100.100 for some services. However we don't want to assign this IP address to the external interface. The problem is that if you don't assign an IP to an interface, you don't respond to ARP requests for that IP. In order to solve this problem we need to configure proxy arp. To demonstrate this, we have a scenario. We have an application server IP of which is 192.168.239.12 in the internal network and application is running on TCP port 8080. We would like everyone on Internet to access this application via TCP port 80 i.e we will redirect TCP80 requests coming to 192.168.100.100 to the internal 192.168.239.12 TCP8080.

#Configure Proxy-arp so that we can respond to ARP requests to this address
set security nat proxy-arp interface ge-0/0/0.0 address 192.168.100.100/32

#Configure TCP8080 custom application
set applications application TCP8080 protocol tcp
set applications application TCP8080 destination-port 8080

#We also need an address book entry for our policy
set security address-book global address appserver 192.168.239.12/32

#Here we configure our pool for nat
set security nat destination pool appserver-internal address 192.168.239.12/32
set security nat destination pool appserver-internal address port 8080

#Destination NAT rule
set security nat destination rule-set internal-servers rule appserver match destination-address 192.168.100.100/32
set security nat destination rule-set internal-servers rule appserver match destination-port 80
set security nat destination rule-set internal-servers rule appserver then destination-nat pool appserver-internal

#And finally security policy allowing TCP8080
set security policies from-zone internet to-zone internal policy allow-appserver match source-address any
set security policies from-zone internet to-zone internal policy allow-appserver match destination-address appserver
set security policies from-zone internet to-zone internal policy allow-appserver match application TCP8080
set security policies from-zone internet to-zone internal policy allow-appserver then permit
Now we do connect to TCP80 port of 192.168.100.100 from 10.100.100.10 Internet host and see the session table

root@srx220> show security flow session destination-port 80
Session ID: 7, Policy name: allow-appserver/7, Timeout: 1792, Valid
  In: 10.100.100.10/45550 --> 192.168.100.100/80;tcp, If: ge-0/0/0.0, Pkts: 3, Bytes: 164
  Out: 192.168.239.12/8080 --> 10.100.100.10/45550;tcp, If: ge-0/0/1.0, Pkts: 2, Bytes: 120
Total sessions: 1

We have redirected port 80 to internal 8080 port.

   

1. Loading default config and setting the root password
   
2. Configuring interfaces and default route
   
3. Configuring security zones
   
4. Configuring address book entries
   
5. Creating security policies
   
6. Creating source nat for internal clients
   

1. Operational mode and this mode has the prompt > on the CLI
   
2. Configuration mode and this mode has the prompt # on the cli
   

• Our zone facing pc clients is named internal
  
• zone facing internet is named internet
  
• Internal clients will be able to reach SRX (i.e ping and ssh service will be enabled) towards SRX