Hi All,
I am having a serious and puzzling issue where my core ASA in the data center, which all of my branch sites come through to get internet, will intermittently cause all traffic flowing through it in an inter-zone fashion (i.e. inside-to-outside, inside-to-DMZ, DMZ-to-inside, etc...) to experience packet loss and high latency (500ms on average). I am sat physically at the data center, and even from my PC, which is a 1ms single hop away from the ASA reports 500ms latency when I try to ping the ISP gateway through my ASA. However, if I ping the ASA interface my PC faces (the inside interface IP on the ASA), pings are fine at 1ms, no packet loss. If I logon to the ASA itself and I ping something on the inside, something in the DMZ, and the very same ISP gateway IP address connected to the outside interface of my ASA, latency is fine, and no packet loss.
Due to these findings, I am theorizing that the ASA is having a problem when the traffic needs to traverse zones (i.e. inside-to-outside). That would explain why I can ping the inside interface of the ASA from my PC and not receive any packet loss, as well as why I can ping something in the Outside, Inside and DMZ zones while sitting on the ASA, pinging from it, and experience no packet loss; Because those ping responses don't require the ASA to traverse zones, whereas any other ping scenario I tried had to go through the ASA (i.e. My inside PC to the ISP router) to reach their destinations and subsequent latency and packet loss was witnessed.
I've attached a diagram that shows everything and also provides all scenarios I've tested and their results. If anyone can provide any insights into what this issue could be and how to go about troubleshooting it, that would be most appreciated, as there is nothing jumping out at me in the logs or the interfaces. Thanks.
