Since PAN-OS version 9.0 you can configure GRE tunnels on a Palo Alto Networks firewall. Greetings from the clouds. As always, this is done solely through the GUI while you can use some CLI commands to test the tunnel. This time Palo put a little stumbling block in there as you have to allow a GRE connection with a certain zone/IP reference. I will show how to set up such a GRE tunnel between a Palo and a Cisco router. Here we go:
Category Archives: Vendor/Device/OS
PoE-powered NTP Display
As you might have noticed, I am playing a lot with NTP these days. Having a networking background I also like Power over Ethernet. So what’s more obvious than using a PoE-powered NTP display for test purposes? ;D
Setting up NTS-Secured NTP with NTPsec
This is a guest blogpost by Martin Langer, Ph.D. student for “Secured Time Synchronization Using Packet-Based Time Protocols” at Ostfalia University of Applied Sciences, Germany.
In the previous posts, I already introduced the Network Time Security (NTS) protocol and described the most important features. Although the specification process has not been completed, there are already some independent NTS implementations and public time servers (IETF106). NTPsec is one of the important representatives of this series and already offers an advanced NTS solution. In this post, I’ll give you a short guide to setting up an NTS-secured NTP client/server with NTPsec.
Intro to NetworkMiner
This is a guest blogpost by Erik Hjelmvik, an expert in network forensics and network security monitoring at NETRESEC.
Wireshark is the default goto tool for analyzing captured network traffic for most network engineers. But there are a few other free and open source alternatives that are sometimes overlooked, one of which is NetworkMiner (disclaimer: I’m the creator of NetworkMiner).
Monitoring a Meinberg LANTIME NTP Server
Monitoring a Meinberg LANTIME appliance is much easier than monitoring DIY NTP servers. Why? Because you can use the provided enterprise MIB and load it into your SNMP-based monitoring system. Great. The MIB serves many OIDs such as the firmware version, reference clock state, offset, client requests, and even more specific ones such as “correlation” and “field strength” in case of my phase-modulated DCF77 receiver (which is called “PZF” by Meinberg). And since the LANTIME is built upon Linux, you can use the well-known system and interfaces MIBs as well for basic coverage. Let’s dig into it:
Basic NTP Client Test: ntpdate & sntp
During my work with a couple of NTP servers, I had many situations in which I just wanted to know whether an NTP server is up and running or not. For this purpose, I used two small Linux tools that fulfil almost the same: single CLI command while not actually updating any clock but only displaying the result. That is: ntpdate & sntp. Of course, the usage of IPv6 is mandatory as well as the possibility to test NTP authentication.
Palo Alto Networks Feature Requests
This is a list of missing features for the next-generation firewall from Palo Alto Networks from my point of view (though I have not that many compared to other vendors such as Fortinet). Let’s see whether some of them will enter PAN-OS in the next years…
Juniper ScreenOS with a 6in4 Tunnel
Yes, I know I know, the Juniper ScreenOS devices are Out-of-Everything (OoE), but I am still using them for a couple of labs. They simply work as a router and VPN gateway as well as a port-based firewall. Perfect for labs.
For some reasons I had another lab without native IPv6 Internet. Hence I used the IPv6 Tunnel Broker one more time. Quite easy with the SSGs, since HE offers a sample config. But even through the GUI it’s just a few steps:
Workaround for Not Using a Palo Alto with a 6in4 Tunnel
Of course, you should use dual-stack networks for almost everything on the Internet. Or even better: IPv6-only with DNS64/NAT64 and so on. ;) Unfortunately, still not every site has native IPv6 support. However, we can simply use the IPv6 Tunnel Broker from Hurricane Electric to overcome this time-based issue.
Well, wait… Not when using a Palo Alto Networks firewall which lacks 6in4 tunnel support. Sigh. Here’s my workaround:
Continue reading Workaround for Not Using a Palo Alto with a 6in4 Tunnel
Using a FortiGate with a 6in4 Tunnel
For some reason, I am currently using a FortiGate on a location that has no native IPv6 support. Uh, I don’t want to talk about that. ;) However, at least the FortiGate firewalls are capable of 6in4 tunnels. Hence I am using the IPv6 Tunnel Broker from Hurricane Electric again. Quite easy so far.
But note, as always: Though FortiGate supports these IPv6 features such as a 6in4 tunnel or stateful/-less DHCPv6 server, those features are NOT stable or well designed at all. I had many bugs and outages during my last years. Having “NAT enabled” on every new IPv6 policy is ridiculous. Furthermore, having independent security policies for legacy IP and IPv6 is obviously a really bad design. One single policy responsible for both Internet protocols is a MUST. Anyway, let’s look at the 6in4 tunnel:
PAN Blocking Details
One of my readers sent me this question:
Let’s have a look:
NTP Authentication at Juniper ScreenOS
Yes, ScreenOS is end-of-everything (EoE), but for historical reasons I still have some of them in my lab. ;D They simply work, while having lots of features when it comes to IPv6 such as DHCPv6-PD. However, using IPv6-only NTP servers is beyond their possibilities. :(
Anyway, I tried using NTP authentication with legacy IP. Unfortunately, I had some issues with it. Not only that they don’t support SHA-1 but MD5, this MD5 key was also limited in its length to 16 characters. Strange, since ntp-keygen per default generates 20 ASCII characters per key. Let’s have a look:
NTP Authentication on Pulse Connect Secure
I initially wanted to show how to use NTP authentication on a Pulse Connect Secure. Unfortunately, it does not support NTP over IPv6, which is mandatory for my lab. Ok, after I calmed down a bit, a configured it with legacy IP and got NTP authentication running. ;) Here’s how:
Infoblox Grid Manager NTP Authentication
Configuring NTP authentication on the Infoblox Grid Master is quite simple. Everything is packed inside the single “NTP Grid Config” menu. You just have to enter the NTP keys respectively key IDs and enable authentication on the appropriate servers. In the case of incorrect authentication values an error message is logged. Very good, since this is not the case on some other network security devices (Palo, Forti).
Too bad that it only supports MD5 while SHA-1 should be used instead of.
Fortinet FortiGate (not) using NTP Authentication
A security device such as a firewall should rely on NTP authentication to overcome NTP spoofing attacks. Therefore I am using NTP authentication on the FortiGate as well. As always, this so-called next-generation firewall has a very limited GUI while you need to configure all details through the CLI. I hate it, but that’s the way Fortinet is doing it. Furthermore the “set authentication” command is hidden unless you’re downgrading to NTPv3 (?!?) and it only supports MD5 rather than SHA-1. Not that “next-generation”!
Finally, you have no chance of knowing whether NTP authentication is working or not. I intentionally misconfigured some of my NTP keys which didn’t change anything in the NTP synchronization process while it should not work at all. Fail!
Continue reading Fortinet FortiGate (not) using NTP Authentication