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IPv6 Renumbering: A Pain in the …
If you’re following my blog you probably know that I am using IPv6 everywhere. Everything in my lab is dual-stacked if not already IPv6-only. Great so far. A few months ago my lab moved to another ISP...
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IPv6 Interface ID Structure
While there are many approaches on how to structure your IPv6 prefix into /64 subnets (blogposts, books, talks) there are only a few hints what you can do with the other 64 bits of the addresses,...
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2001:db8::/32 in the Wild
If you have ever read some docs or RFCs about IPv6 you should be quite familiar with the [crayon-5ba3e96db692e940520243-i/] “IPv6 Address Prefix Reserved for Documentation”, RFC 3849. This RFC clearly...
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Basic MP-BGP Lab: Cisco Router, Palo Alto, Fortinet
While playing around in my lab learning BGP I configured iBGP with Multiprotocol Extensions (exchanging routing information for IPv6 and legacy IP) between two Cisco routers, a Palo Alto Networks...
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MP-BGP Capture
For those who are interested in analyzing basic BGP messages: I have a trace file for you. ;) It consists of two session establishments as I cleared the complete BGP session on two involved routers for...
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OSPFv2 Capture
I already had an OSPFv2 for IPv4 lab on my blog. However, I missed capturing a pcap file in order to publish it. So, here it is. Feel free to have a look at another small lab with three Cisco routers...
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OSPFv3 with IPsec Authentication
Here comes a small lab consisting of three Cisco routers in which I used OSPFv3 for IPv6 with IPsec authentication. I am listing the configuration commands and some show commands. Furthermore, I am...
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Dual-Stack EIGRP Lab
Yet another routing protocol I played with in my lab. ;) This time: EIGRP, Enhanced Interior Gateway Routing Protocol, the proprietary distance-vector routing protocol developed by Cisco, which is now...
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EIGRP Capture
And again: Here comes a pcapng capture taken for the dynamic routing protocol EIGRP. If you want to dig into EIGRP messages, download the trace file and browse around it with Wireshark. Since I used...
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Using Cisco’s IOS Archive
Cisco’s IOS offers an easy to use feature for configuration versioning to an external server such as TFTP or SCP. Furthermore, you can use IOS commands to compare any two snapshots and to roll back to...
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My CCNP TSHOOT Lab: The Overall Picture
During the last few weeks I published a couple of blogposts concerning routing protocols such as BGP, OSPFv3, and EIGRP. (Use the “Cisco Router” tag on my blog to list all of them.) They are all part...
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SharkFest’18 Europe: Crash Course: IPv6 and Network Protocols
I did a session at SharkFest’18 Europe in Vienna with the title of “Crash Course: IPv6 and Network Protocols“. Since the presentation slides + audio were recorded you can listen to the talk, too. Here...
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Trying to change an IPv6 Link-Local Address on a FortiGate
I got an email where someone asked whether I know how to change the link-local IPv6 addresses on a FortiGate similar to any other network/firewall devices. He could not find anything about this on the...
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Single DNS Query – Hundreds of Packets
I was interested in how a recursive DNS server resolves DNS queries in detail. That is, not only the mere AAAA or A record, but also DNSSEC keys and signatures, the authority and additional section...
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My Network Gadgets
This post is not about software but hardware tools for network admins. Which network gadgets am I using during my daily business? At least three, namely the Airconsole, the Pockethernet and the...
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Infoblox Features & Licenses Naming Clarity
Working with Infoblox can be challenging when it comes to their naming of features, licenses, marketing slides, and GUI options. So let’s bring some clarity into this chaos. :D I have listed the most...
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Why should I run own NTP Servers?
… since we all can use pool.ntp.org ? Easy answer: Many modern (security) techniques rely on accurate time. Certificate validation, two-factor authentication, backup auto-deletion, logs generation, and...
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Packet Capture: Network Time Protocol (NTP)
What’s the first step in a networker’s life if he wants to work with an unknown protocol: he captures and wiresharks it. ;) Following is a downloadable pcap in which I am showing the most common NTP...
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NTP Server via DCF77 on a Raspberry Pi
In this tutorial I will show how to set up a Raspberry Pi with a DCF77 receiver as an NTP server. Since the external radio clock via DCF77 is a stratum 0 source, the NTP server itself is stratum 1. I...
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NTP Server via GPS on a Raspberry Pi
This post shows how to use a GPS receiver with a Raspberry Pi to build a stratum 1 NTP server. I am showing how to solder and use the GPS module (especially with its PPS pin) and listing all Linux...
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