You can now get direct from Manito Networks. And by Tyler Hart are both available in paperback and Kindle! PrefaceMikrotik routers straight out of the box require security hardening like any Arista, Cisco, Juniper, or Ubiquiti router. Some very basic configuration changes can be made immediately to reduce attack surface while also implementing best practices, and more advanced changes allow routers to pass compliance scans and formal audits. Almost all of the configuration changes below are included in requirements for PCI-DSS and HIPAA compliance, and the best-practice steps are also included in CIS security benchmarks and DISA STIGs.
Router Configuration InterfaceIPIn UseDescriptionether1192.168.88.181/24YesWANether210.1.157.1/24YesManagementether3192.168.0.1/24YesLANether4NoneNoN/Aether5NoneNoN/AThis is a typical branch office configuration with Inside, Outside, and Management network 'zones'. It could very easily be an RB-751 in a home office, or an RB-951 or hAP in a branch office. Tyler Hart is a networking and security professional who started working in technology in 2002 with the US DoD and moved to the private sector in 2010.
Website Blocking Policy With MikroTik RouterOS Presented by Michael Takeuchi.Static DNS will replace the IP of Original Server with fake IP and make your client host can’t access the actual server by domain. Website Blocking Policy with MikroTik RouterOS. MikroTik RouterOS (v6) Training Traffic Control Vahid Shahbazian fard jahromy www.LearnMikroTik.ir Schedule.09:00 – 10:30 Morning Session I. Remote DNS server, as all caches - it minimizes resolution time.DNS cache also can act as DNS server for local.
He holds a Business degree in IT Management, as well as the CISSP certification and others from Microsoft, CompTIA, Cisco, (ISC)2, Tenable Network Security, and more. For over 15 years he has worked and consulted with large and small organizations including hospitals and clinics, ISPs and WISPs, U.S. Defense organizations, and state and county governments.
Tyler Hart is a networking and security professional who started working in technology in 2002 with the US DoD and moved to the private sector in 2010. He holds a Business degree in IT Management, as well as the CISSP certification and others from Microsoft, CompTIA, Cisco, (ISC)2, Tenable Network Security, and more. For over 15 years he has worked and consulted with large and small organizations including hospitals and clinics, ISPs and WISPs, U.S. Defense organizations, and state and county governments.
A few years back, I wrote a guide about using. I have since moved on to using Mikrotik as my primary routing device and have implimented a similar DNS based adblock. Here’s how I did it combining various resources online.At the time of the last article, I was using one of those old, underpowered Linksys WRT54Gs. You probably know the type I am talking about, the black/blue boxes made by Linksys when they were a standalone company.
After my network outgrew the old Linksys router, I “upgraded” to a. I say “upgraded” because I immediately flashed OpenWRT onto the device and never looked into RouterOS. I forgot why I flashed back to factory firmware on the Mikrotik, but after using it for a while now, I can’t imagine using anything other than RouterOS, even good old OpenWRT.The basic idea of DNS based adblocking is this: any device on your network goes to a website and when that website has an advertisement on it, the ad is usually directed to a known advertising website for just that box/ad/display on the web page.
With DNS based adblocking, your browser tries to look up the advertising site, but is instead presented with a special dead IP address and the advertisement does not load. This works network-wide across all devices including phones, tablets, computers, etc. The Setup. Mikrotik router with at least 64 MB RAM free, not total. Mikrotik router running the latest RouterOS.
Latest WinBox for Mikrotik. Some basic networking knowledge regarding IP routing, firewalls, etc.The following config file contains a list of known advertising domains from and pre-converted into Mikrotik’s config format. Extract the DNS config file below and upload the.rsc into Mikrotik:WinBox Files Upload.
mikrotikadblock.rscWinBox Terminal /import mikrotikadblock.rscThis configuration will load a list of domains into the DNS static entries with an IP address of 240.0.0.1. You can confirm the import by checking the DNS static records: WinBox IP DNS StaticNow we need to setup a firewall rule to block the special IP address 240.0.0.1. When it comes to blocking via firewall rules, I prefer to use not use “drop” because this results in the requesting agent trying over and over until it times out. Instead, we will give immediate feedback that the request is denied so our web browsers don’t hang up trying to load a page element.Rejecting TCP attempts: WinBox IP Firewall Filter Rules Add +GeneralChain: forwardDst.
Address: 240.0.0.1ActionAction: dropLog: checkedLog Prefix: ADBLOCKComment: Adblock dropMake sure that our DHCP clients are using our Mikrotik as a DNS server: WinBox IP DHCP Server Networks Edit Primary NetworkDNS Servers: Make sure that our Mikrotik is using OpenDNS for DNS lookups: WinBox IP DNSServers: 208.67.222.222208.67.220.220Allow Remote Requests: checkedForce all of our clients on the network to use our DNS, even if they try to use their own DNS servers: WinBox IP Firewall NAT Add +GeneralChain: dstnatDst. Address: !
Protocol: 6 (tcp)Dst. Interface: ActionAction: redirectTo Ports: 53Comment: DNS Redirect (TCP) WinBox IP Firewall NAT Add +GeneralChain: dstnatDst. Address: !
Protocol: 17 (udp)Dst. Interface: ActionAction: redirectTo Ports: 53Comment: DNS Redirect (UDP)Hooray! Now all of your network clients should be forced to use your Mikrotik’s DNS server which will use static entries for the known advertising/malware domains.You will also be performing DNS lookups using OpenDNS, so you can setup an OpenDNS account and provide additional web content filtering using OpenDNS.
By default, OpenDNS will only filter out the really bad stuff such as known malware sites. You have to enable additional content filtering under your OpenDNS account if you want a more strict web content filtering policy. Caveats. This method does not auto update. There is a limit to what Mikrotik can handle as far as processing scripts and automating this. You can find guides online for setting up a.php script on your own webserver to automatically download malware domain lists and create Mikrotik’s.rsc config for you. Your device must have at least 64 MB RAM free.
Mikrotik’s DNS caching takes a lot of RAM. It loads the entire static DNS list (13,000+ domains) into memory upon boot and does not read them from file when performing DNS lookups. I have limited my domain list in the.rsc to only the list from because of this. There are guides out there that let you have lots of domain lists, but your Mikrotik’s performance will suffer and require more RAM. Your Mikrotik will take longer to reboot.
Because the entire list is loaded into memory at boot, you will have a longer reboot cycle while the entire list is loaded into memory. This setup on my increased the reboot time from about 5-10 seconds to about 60 seconds. Again, I am only using one domain list, there are guides out there that have 3-4 different domain lists and I would expect longer reboot times and higher memory usage to reflect even more entries.
Some websites will complain you are adblocking. Even if you disable other adblock browsing plugins, some websites will still complain. I have also seen some video websites not playing videos because they are trying to show an ad before the video.
You can look into what domain is being used and disable or delete the static DNS entry to allow the website’s ads.Aside from those caveats, the performance is fast after the Mikrotik is rebooted and ready. DNS lookups are fast, and there is no noticeable difference in web browsing speed.Happy Adblocking! My method isn’t tested on a network at that scale. My little RB951 would cry with such a large network!Edit: Whoops, I thought you meant 10k network endpoints. I am running I think 13,000 DNS “adblock” rules, about 50-75 firewall filter, NAT, and mangle rules, 20/5 internet connection, with 8 in/out queue tree priority levels to keep everything moving (VOIP, gaming).
I also have an isolated guest Wifi providing the neighborhood with a free WiFi hotspot. My internet speed is modern but not fast, Mikrotik’s CPU peaks around 50% when under full internet load. My technique is an amalgamation of several different adblock schemes I researched.127.0.0.1 is also known as “localhost” and is commonly used. It causes DNS lookups to try to utilize resources on the requesting device’s “self”. 99% of cases, there is no service running on the requesting device and the request likely goes into a timeout.
When there is a service port running against an ad request, it can cause delays while the ad tries to run but doesn’t get the data it wants.Using 240.0.0.1, we force the requesting device to try to communicate outside of the LAN network. The key here is that we now have control over the attempt and can reply back (reject the packet) at our firewall with a tcp reset, port unavailable, etc.Rejecting packets instead of just dropping notifies the requesting service and leads to an instant failure rather than the application request getting dropped and retrying over and over due to no response.TL:DR; Not all advertisement applications request data over http(s) from their domains. 127.0.0.1 gives the adblocker less control over the connection attempt.