I have found some other solutions more insightful and user-friendly as compared to Cisco Catalyst SD-WAN, but the basic SD-WAN functionality is good enough. I am using it only because it was done as a pilot project, specifically for my 60 to 70 sites. For the majority of the sites, I am using Fortinet's Secure SD-WAN solution and I found that more viable and more in alignment with my requirements. For example, there is not any Internet Service Database available in Cisco Catalyst SD-WAN intrinsically. If I want to write a policy based on applications, I am not able to write it, at least in Cisco Catalyst SD-WAN Viptela deployment that we have done, and that is fairly easy to do in Fortinet. The second issue is the logging capability. I think the visibility that Fortinet Secure SD-WAN has is not even comparable. Cisco Catalyst SD-WAN does not provide that sort of insight or control as far as traffic steering is concerned. With respect to the SLAs, I barely know which sort of SLAs are violated in Cisco Catalyst SD-WAN, so I do not have clear visibility on where the traffic is moving from at my spoke or hub locations. I believe Fortinet gives me a very clear picture of where the traffic is going. Overall visibility, whether it is data traffic or logs, is much better in Fortinet compared to Cisco Catalyst SD-WAN. The complexity of Cisco Catalyst SD-WAN Viptela is noticeable and quite complicated to configure. If something breaks, you have to involve TAC and others to fix it. On the contrary, you can work with underlays. Even if your IPsec overlay tunnel is down, it does not impact your production. Thus, we find Fortinet's solution significantly better than Cisco Catalyst SD-WAN solution. I have used Application-aware Routing in Cisco Catalyst SD-WAN. However, I found it to be very complicated, especially regarding policy writing. For my breakout of VC traffic, we had to write a bunch of IP addresses for Zoom, Webex, and others. Presently, it can only identify Webex as an application, and I highly doubt whether there is any application identification for Zoom and other platforms, as we were not able to find it during our implementation. It is done through static whitelisting of the IPs, which is not a scalable solution since IPs can change at any time. Overall, the application-aware routing policies are not as flexible and scalable as the Internet Service Database feature of Fortinet provides. The struggles encompass policy writing, logging capabilities, traffic visibility, and complex configuration. There is also the issue of load balancing. We have faced considerable challenges with traffic load balancing between the links. Although the SLA targets are configurable, understanding how traffic flows is challenging, making troubleshooting exceedingly difficult. Overall, I find it a quite complicated solution with not that much operational usability.
