So a single ISP isn’t cutting it anymore you need a backup just in case the primary fails and might as well add a second ASA into this design, more redundancy equals more up-time, right? On paper it sounds good but in the “real” world there probably is tipping point, more redundancy increases complexity. In this post we’ll aim to keep it simple, with setting up a Cisco ASA HA active/standby pair and then add in the second ISP. Let’s get started!
I keep doing the automation dance, there are a lot of different tooling products out there. I have been trying to understand a use case around using it with network automation. Recently I have been dancing around with Ansible. My personal belief is that using any type of these tools would be helpful but it can be a steep learning curve if you really don’t have any programming knowledge. This is not something that is relatively easy to use or understand, don’t expect to have a working network automated tool in production on day one. I think this is great for learning, and using this in a network sandbox. If you don’t have programming mindset it might make your job harder on day one before it gets easier, but just like learning to dance you have to learn the steps, the moves, and maintain the rhythm. So with that let’s at least figure out the starting points, and begin learning the steps of the automation dance. 😉 Continue reading “Automation Dance”
So, recently we enforced some firewall rules on a new environment, we did testing of the environment and everything was working as expected. In about 24 hours a lot of traffic from the web infrastructure was being denied and it continued, at first glance it looked like return traffic was being dropped, the web servers were sourcing at port 443 and the destination ports were using dynamic ports (RFC 6335)
No user or application problems were reported when we enforced rules, and we waited additional days to see if anything came up. Nothing came up, the only thing was a spike in amount of syslog messages of dropped traffic coming from the web servers. So from that point it really wasn’t an issue, but I thought it would be interesting to see what was going on. Continue reading “Too Many TCP Resets”
If you don’t already know, site to site VPNs can be a cost-effective way for remote sites to connect to HQ resources instead of a lease line like using MPLS or Metro-E circuits. We can instead use a standard internet connection with a static IP, this is usually cheaper than a dedicated circuit. Our next steps are purchasing a firewall for the remote site (assuming you already have one at HQ) and setup a site to site VPN connection to make the connection. Continue reading “ASA Site to Site VPN (DHCP)”
I’ve found this table that I created a while ago and it lists common WAN connections that businesses use. I have used this table like a reference guide to familiar myself into other protocols. People don’t think of it much but the WAN is a different beast compared the LAN as it uses different protocols besides Ethernet. The WAN or wide area network is what connects us to remote locations within a organization. If we have an office in New York and another office in Wyoming we need these offices to be connected to each other so that they seem to be on the same network even though they are miles away these types of WAN connections and protocols would do it. Continue reading “Types of WAN Links”