Some months ago, my co-worker and I ran into an interesting issue: a notebook with a newly installed Ubuntu 20.04 does only work with IPv4, but this office network is dual-stacked (IPv4 and IPv6). Other Linux clients as well as Windows and Mac systems still work fine. They all get an IPv4 configuration by DHCPv4 and an IPv6 configuration by stateful DHCPv6 from the same DHCP server, relayed by a Cisco ASA 5500-X. What’s wrong with Ubuntu 20.04?
More than 6 years ago (!) I published a tutorial on how to set up an IPsec VPN tunnel between a FortiGate firewall and a Cisco ASA. As time flies by, ASA is now able to terminate route-based VPN tunnels (which is great!), we have IKEv2 running everywhere and enhanced security proposals. Hence, it’s time for an update:
More than 6 years ago (!) I published a tutorial on how to set up an IPsec VPN tunnel between a Palo Alto Networks firewall and a Cisco ASA. As time flies by, ASA is now able to terminate route-based VPN tunnels (which is great!), we have IKEv2 running everywhere and enhanced security proposals. Hence, it’s time for an update:
There are two methods of site-to-site VPN tunnels: route-based and policy-based. While some of you may already be familiar with this, some may have never heard of it. Some firewalls only implement one of these types, so you probably don’t have a chance to configure the other one anyway. Too bad since route-based VPNs have many advantages over policy-based ones which I will highlight here.
I had many situations in which network admins did not know the differences between those two methods and simply configured “some kind of” VPN tunnel regardless of any methodology. In this blogpost I am explaining the structural differences between them along with screenshots of common firewalls. I am explaining all advantages of route-based VPNs and listing a table comparing some firewalls regarding their VPN features.
When using a multilayer firewall design it is not directly clear on which of these firewalls remote site-to-site VPNs should terminate. What must be considered in such scenarios? Differentiate between partners and own remote offices? Or between static and dynamic peer IPs? What about the default routes on the remote sites?
Following is a discussion about different approaches and some best practices. Since not all concepts work with all firewall vendors, the following strategies are separated by common firewalls, i.e., Cisco ASA, Fortinet FortiGate, Juniper ScreenOS, Palo Alto.
Since a few weeks I am using Tufin SecureTrack in my lab. A product which analyzes firewall policies about their usage and their changes by administrators (and much more). Therefore, the first step is to connect the firewalls to SecureTrack in two directions: SSH from SecureTrack to the device to analyze the configuration, as well as Syslog from the device to SecureTrack to real-time monitor the policy usage.
This blog post shows the adding of the following firewalls into Tufin: Cisco ASA, Fortinet FortiGate, Juniper ScreenOS, and Palo Alto PA.
The native Android IPsec VPN client supports connections to the Cisco ASA firewall. This even works without the “AnyConnect for Mobile” license on the ASA. If only a basic remote access VPN connection is needed, this fits perfectly. It uses the classical IPsec protocol instead of the newer SSL version. However, the VPN tunnel works anyway.
In this short post I am showing the configuration steps on the ASA and on the Android phone in order to establish a remote access VPN tunnel.
Similar to my test lab for OSPFv2, I am testing OSPFv3 for IPv6 with the following devices: Cisco ASA, Cisco Router, Fortinet FortiGate, Juniper SSG, Palo Alto, and Quagga Router. I am showing my lab network diagram and the configuration commands/screenshots for all devices. Furthermore, I am listing some basic troubleshooting commands. In the last section, I provide a Tcpdump/Wireshark capture of an initial OSPFv3 run.
I am not going into deep details of OSPFv3 at all. But this lab should give basic hints/examples for configuring OSPFv3 for all of the listed devices.
Cisco ASA 9.4 (and later) is now supporting Policy Based Routing. Yeah. Great news, since many customers are requesting something like “HTTP traffic to the left – VoIP traffic to the right”. Coming with a new Cisco ASA 5506-X I was happy to try the policy based routing feature.
The configuration steps through the ASDM GUI are not easy and full of errors so I am trying to give some hints within this blog post.
Since IPv6 gets more and more important, I am using it by default on all my test firewalls, which of course support IPv6. However, when comparing the different functions and administration capabilities, they vary significantly.
Here comes my short evaluation of the IPv6 functions on the following four firewalls: Cisco ASA, Fortinet FortiGate, Juniper SSG, and Palo Alto.
Following is a step-by-step tutorial for a site-to-site VPN between a Fortinet FortiGate and a Cisco ASA firewall. I am showing the screenshots of the GUIs in order to configure the VPN, as well as some CLI show commands.
I constructed a MRTG/Routers2 configuration template for the Cisco ASA firewall which consists the OIDs (graphs) for the interfaces, CPU, memory, VPNs, connections, ping times, and traceroute hop counts. With only four search-and-replace changes as well as a few further specifications, the whole SNMP monitoring for that firewall is configured.
You often have comparisons of both firewalls concerning security components. Of course, a firewall must block attacks, scan for viruses, build VPNs, etc. However, in this post, I am discussing the advantages and disadvantages from both vendors concerning the management options: How to add and rename objects. How to update a device. How to find log entries. Etc.
I tested OSPF for IPv4 in my lab: I configured OSPF inside a single broadcast domain with five devices: 2x Cisco Router, Cisco ASA, Juniper SSG, and Palo Alto PA. It works perfectly though these are a few different vendors.
I will show my lab and will list all the configuration commands/screenshots I used on the devices. I won’t go into detail but maybe these listings help for a basic understanding of the OSPF processes on these devices.
In a basic environment with a Cisco ASA firewall I am logging everything to a syslog-ng server. As there aren’t any reporting tools installed, I am using grep to filter the huge amount of syslog messages in order to get the information I want to know. In this blog post I list a few greps for getting the interesting data.