IPSec is the protocol one can use to establish a Site-to-Site VPN , as it is widely used because its an open standard protocol which offers secure and encrypted communication over the public internet domain. IPSec works at Network later and only pass unicast traffic. I will brief you all about how IPSec works
IPSEC works on 5 parameters
- Interesting Traffic
- Phase 1 (ISAKMP/ IKEv1)
- IPSec device negotiate an IKE Security Policy & establish a secure channel for communication
- Phase 2 (IPSEC)
- IPSec devices negotiate an IPSec security policy to protect data
- Data Transfer
- Data is transferred based
- IPSec parameters
- Keys negotiated
- Data is transferred based
- IPSec Tunnel Terminated
- IPSec SAs terminate when timing out or a certain data volume is reached
We will be using the following topology to configure site-to-site IPSec VPN between two Cisco Routers. In the upcoming post lets see how to configure the Site-to-Site IPSec VPN using Cisco Routers
When it comes to following the best practices for any Network Security Appliances, one should configure a Login Banner. Configuring a Login Banner in Palo Alto Networks Firewall is quite simple . Lets see how we can configure a login banner in Palo Alto Networks Firewall
Step 1:Device>Setup>Management>General Settings(Edit Icon)
Step 2 : Device>Setup>Management>General Settings(Edit Icon)>Login Banner
Type the Organization approve banner in the Banner Box as shown below and click ok
By following these simple step one can configure a Login Banner in Palo Alto Network Firewall. When ever someone tries to SSH or login using a browser he/she will see the below screen with Login Banner
Palo Alto Firewalls uses security policies to either allow or deny an access, Security Policies comprises of a list of security policy rules. Each Security policy rule comprises of objects like
- Address both source and destination
- Url Category
One can either use all the objects or some of the objects to configure a Security Policy rule (depends on the purpose of the policy). The Palo Alto Firewall takes an action for configured security policy only when a session matches all the defined fields of the security policy.
The above shown Security Policy will block YouTube access only when the session is sourced from trust zone with users alldevelopers and yasir, and destined towards untrust zone with an attempt to access YouTube, then the action the Palo Alto Firewall take is to block the YouTube access.
Like any other firewall, Palo Alto Networks Firewalls adopts the top down approach to evaluate the security polices and takes an action based on the matching policy, if the policy is found no further rules are evaluate, if not it keeps on looking for match until the last rule is evaluated. If there were no matches found the session will be dropped.
In our next post we will discuss more about Security Policy rules types.
In one of my previous post we discussed about Palo Alto Networks Firewall Virtual Router , how it works and what kind of protocols its capable of supporting. Configuring a static route in Palo Alto Firewall Virtual Router is quite simple, in this post lets see how we can configure a static route.
We will be using the following topology for our example
We have LAN with the subnet 172.16.32.0 which is the trust zone will accessing the Internet from the Network 192.168.1.0 which is untrust zone.
In order allow the internet access you should ensure that there is a default route toward the Internet gateway 192.168.1.1 and the Palo Alto Layer 3 interface s of both trust and untrust zone are configured with the following
In order to configure a default route in the Palo Alto Networks Firewall we need to do the following
Step 1 :Go to Network>Virtual Routers
Click Virtual Routers> default>Static Routes>Add
(Palo Alto firewall comes a Virtual Router default, if you want you can create a new virtual router and name according to your needs)
Step 2: Configure the default route towards Internet Gateway IP address as shown below
In our case any traffic sourcing from trust zone will be sent to the Internet Router IP Address as it default gateway ,
We will name the route as Static Route
Destination field will be 0.0.0.0/0 as any traffic that don’t have any specific route will be forwarded to Internet Gateway.
Select IP Address radio button in the Next Hop Field
Enter the IP address and mask 192.168.1.1/24
Click OK and save the configuration.
Make sure you configure a Security- Policy to allow the traffic from trust zone to untrust zone as shown below.
You can see from my laptop with an IP Address 172.16.32.2 I can ping the Inter gateway 192.168.1.1 and can also access internet.
You could see it s very to configure a static route in Palo Alto Firewall and one can see the routing table as shown below.
With the introduction of Cisco VIRL 1.0.0,capturing the traffic has become quite simpler. One can now directly click the link on a device and do a packet capture. , in this post lets see how we can capture the traffic in Cisco VIRL and analyse it.
Step 1: Login in to VRIL server form your web browser and you should see below screen, click on User Workspace Management (UMW)
Step 2 : Login to UWM portal using default credentials
Step 3: Select Overview and look out for active simulations and click the simulation you want to do the packet capture
Step 4: Select the node and interface you can to do the pack capture and click the eye shaped icon as demonstrated below
Step 5: Select Offline Capture and apply any filter needed and click create, in my case I am capturing all the traffic no filters are applied
Step 6: Download the capture data and analyze it using Wireshark
Below is the Wireshark snap shot of packet capture I did
The new Cisco VIRL 1.0.0 is really offering some cool Packet capturing features which are very easy to use
Cisco VIRL comes with an internal SSH and Telnet client which is quite good and it opens all the SSH and telnet sessions within VMMaestro GUI, but if some one wants to use Secure CRT on their MAC as external client, one can easily configure the changes in VIRL VMMaestro,
Change the title format to : %s
Select : Use external terminal applications
Use the following fields show below
By doing these minor changes you can use Secure CRT to SSH or Telnet VIRL Devices
When it comes to routing traffic between different networks one needs a router. Palo Alto Networks Firewalls are capable of routing the traffic between networks. Palo Alto uses a concept of “Virtual Routers” to route the traffic be it static routing or dynamic routing. Virtual Router uses virtualized or partitioned routing tables to do the routing job. Palo Alto Firewalls uses virtual routers to obtain the routes and uses best route to populates its routing table.
Palo Alto Networks Firewall is capable of supporting Dynamic routing protocols like RIP v2, OSPF ( OSPF v2 and V3) and BGP v4. The Palo Alto Network Firewalls comes with a Virtual router named default which can be used for routing provided the layer 3 interfaces or VLANs are part of that default Virtual router. One can also create a new Virtual Router and name it according to his/her organization standards and use it for both static routing and dynamic routing.
Palo Alto Networks Firewalls does comes with a dedicated out -of-band Management (MGT) Interface which is used to manage the Palo Alto Network Firewalls. By default SSH , HTTPS and ping is enabled to manage the Palo Alto Network Firewalls, apart from dedicated out-of-band management interface one can use any Layer 3 interface for the management of the Palo Alto Network Firewalls.
In order to manage the Palo Alto Network Firewalls using a Layer 3 interface one must enable a management profile . In order to configure the management interface follow the below mentioned steps
Network>Network Profiles > Interface Mgmt > Add
Configure the management profile by giving the name you like and select the services you want permit along with the IP address if you want.
Assign the Management Profile to any Layer 3 interface from where you want to manage the Palo Alto Networks Firewall as shown below.
Network>Interfaces>Ethernet> ethernet1/1>Advance>Management Profile
Management Profile is a quite good option, which comes quite handy when you want to allow management functions on any layer 3 interface.
Like any other firewalls, Palo Alto Networks Firewall can be deployed in Layer 2 mode. In a Layer 2 deployment mode, the Palo Alto Networks Firewalls provides switching between two or more networks. In Layer 2 deployment mode, a Vlan must be assigned each interface or Vlan object and additional layer 2 sub interfaces must be assigned to group of interfaces. The Palo Alto Networks Firewall will perform VLAN tag switching when Layer 2 sub interfaces are attached to a common VLAN object.
Palo Alto Networks Firewalls Layer interfaces are only capable of supporting 802.1Q trunks, however they are not capable of supporting any spanning tree protocols (STP) nor do they participate in spanning tree process. Palo Alto Networks Firewalls simply forwards the BPDUs, it receives from the peer Switch.
In past few posts we were talking more about what is Virtual wire? and how it can be implemented. Lets talk briefly about the Virtual wire sub interfaces in this post.
Virtual Wire Sub interfaces are quite useful when one needs to manage traffic in a multi-tenant network setup. It does offer lot of flexibilities in enforcing distinct policies especially when multi-tenant network are in place. Once can easily separate and classify traffic into different zones by using either VLAN tags or VLAN tags in conjunction with IP Classifiers. Yet one more deployment flexibility offered by Palo Alto Networks firewalls.