Archive for the ‘Juniper’ Category

New route-server available!

Friday, September 3rd, 2010

I have been working on a new project which is to provide a service that would allow you to peer with my router over BGP. My router would then advertise a list of bogons and known malicious networks including botnet command and control networks. You can then drop these networks at your border router thus protecting your network from attacks and saving precious router and firewall resources. Right now I am not offering the peering service but I do have a route-view server available that allows you to login and get a full list of the malicious ip networks for ipv6 and ipv4. To access the router please ssh to If you have ipv6 access there is a AAAA record as well, allowing you to access the router on both ipv4 and ipv6.

SSH Brute Force Mitigation in Junos

Wednesday, November 11th, 2009

I have several Juniper SRX-210 devices configured in remote offices. One of the biggest problems I have is that there are a lot of people that are constantly running scripts against the ssh daemon. Now I could lock it down to only a specified list of allowed IP addresses. This would be the most secure method but i have a business requirement of being able to connect to this device from many different location. There is a command you can use to mitigate brute force attempts.

The command limits the number of ssh attempts per minute per source ip to 2. Just enough incase you make a mistake during login, but not enough for a script kiddie to run 500 attacks a minute against your firewall.

services {
   ssh {
     rate-limit 2;

Public DMVPN network.

Saturday, October 3rd, 2009

I was thinking about a new project idea. I was thinking of setting up a dynamic multipoint VPN concentrator. Put a small LAN behind it with a couple of servers. Put the configuration instructions on a webpage for Juniper and Cisco devices. I was thinking to run BGP routing protocol over the interface as it scales reasonably well.

The important part here is I wanted to create a web form which requests the internal and external address ranges of anyones network. Once that person submits that information I will have a Peal script pull those messages from the web form, parse the information, insert the networks and IP addresses into a J-Script template and apply it to my Juniper SRX router automatically.

This project will enable Cisco and Juniper students to participate in the environment and create a public VPN network where p2p APPS and anything else can run over the network without having to worry about any prying eyes. I want to see how far this project will scale. I was even envisioning a time when other people with idle equipment can volunteer to become a secondary hub to take some of the load once my connection reaches 10 thousand or so tunnels. Because of the way DMVPN works. The tunnels between sites will open up as needed when a user from site A needs to talk to site B. This combined with using BGP as the routing protocol will mean that it will require very little bandwidth as traffic destined from site A to C will not transit site B if site B in this scenario is the hub.

Anyways if anyone out there is interested please leave a comment.

Introduction to Filter list for JUNOS

Sunday, June 14th, 2009

Junipers JUNOS is a very robust operating system, not only is the OS very advanced but the ASIC heavy design of Juniper hardware is akin to calorie free chocolate bars! Juniper Filter Lists which are non-stateful packet filters similar to Cisco Access-Lists are compiled and processed using hardware, what this means is that you can have as many Filter-Lists as you want and as long as you want without degrading performance.

Juniper is also big on naming things, in JUNOS everything has a name, the Filter Lists have names, the terms in the Filter Lists have names, and even the address’s you are matching on have names. This is a big concept in JUNOS because it allows you to write snippets of Filter-Lists and use them for many different Filter Lists. JUNOS also supports grouping Filter Lists and applying an entire group of filter to an interface. If you apply Filter groups to a JUNOS interface they individual Filter Lists are evaluated in order sequentially.

Checkpoint —> juniper VPN

Thursday, September 4th, 2008

Recently at work we had a remote site go down. The site was on an ancient pix 506e vpn firewall router. We were in the proccess of switching to a different vpn solution. because of this we had a new Juniper ssg20 firewall device on site.


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