Within Azure you have a Virtual Network is contained within a Azure region. The first important aspect is the Virtual Network. Here is a simple overview of the networking flow for the main components within Azure.įull Azure Networking picture here –> Azure Networking Overview

Now before we start there it is important to understand how traffic flows within Azure with the different services in there. So therefore I wanted to talk a bit about how networking in Azure works on a deeper level and how to troubleshoot network traffic flow with different scenarioes. For those that are used to “Cisco” troubleshooting or network troubleshooting, moving that knowledge to Azure is not that straight forward. I'm totally confused.I was recently involved in a scenario where I was tasked at troubleshooting why some features were not working in Azure, related to traffic flow between a service in Azure and virtual machine on-premises. How should I fix this? It seems my DNS is totally broken. And if that's not bad enough, I've had to reset my router twice in last week (OpenWRT) because sometimes DNS would break altogether, and Wireshark would show that my local domain, '.lann' was being added to every single query the system made, for example: Is this normal? Is dnsmasq interfering with DNSCrypt-proxy? I tried running dnscrypt without a dns cache, but than I noticed that queries to my localhost and sometimes local network were being forwarded to the nameservers. It even happens for broadcast addresses: 125 37.371037000 localhost localhost DNS 90 Standard query 0x8e53 PTR Įverytime this happens, the queries are followed by a bunch of 'conntecion resets' and other warnings.

13.0.8.10.in-addr.arpa.13.0.8.10.in-addr.arpa.Īnd let's say my VPN server IP is 123.456.78.91, than the queries look like this: 9143 584.912799000 localhost localhost DNS 88 Standard query 0xc198 PTR 19.78.Īnd of course, the answer to these queries are always this: 9144 584.912945000 localhost localhost DNS 88 Standard query response 0xc198 No such name

Firstly, after disconnecting from my VPN, with the hypothetical IP address of 10.8.0.13, I see this. When running a dumcap via Wireshark, I've noticed a couple of odd occurrences lately. I have been using DNSCrypt with dnsmasq on my Ubuntu 14.10 machine.

Wireshark ip addresses showing up as