An offloaded session will display 'layer7 processing: completed' in the show session details. Offloaded sessions can't be captured so offloading may need to be disabled temporarily.When filtering is enabled, new sessions are marked for filtering and can be captured, but existing sessions are not being filtered and may need to be restarted to be able to capture them.This option should be used only if instructed by the support and on a low volume time of day as it will capture everything. Pre-Parse Match is a feature that can capture all files before they are processed by the engines running on the dataplane, which can help troubleshoot issues where an engine may not be properly accepting an inbound packet.Packets are captured on the dataplane vs on the interface (this explains the next bullet).Packet captures are session-based, so a single filter is capable of capturing both client2server and server2client.Four filters can be added with a variety of attributes.If you capture without a filter, you can then look at all the headers to see if there was any encalsulation and then change your capture filter accordingly.The first place to go is the Packet Capture menu on the GUI, where you can manage filters, add capture stages, and easily download captures.īefore we get started, there are a few things you should know: You can do this with the filter vlan and host x.x.x.x.Īnother option is that the traffic is PPPoE encapsulated, this means there is a PPPoE header and you can adjust the filter to pppoes and host x.x.x.x. This means the BPF filter needs to know that there is a vlan tag present to change the offsets accordingly. When vlan tagging is used, there are 4 additional bytes between the ethernet header and the IP header. The host x.x.x.x filter looks at offset 26 or offset 30 in the packet for the IP address. Usually when this happens, the traffic is encapsulated. This means that the filter needs some adjustment. So you also see the packets for IP x.x.x.x when not using a filter, but you don't see them when using the BPF filter host x.x.x.x. The fact that you see the traffic when not using a filter seems to confirm this assumption. This means all traffic between the monitored system and the switch/router should be visible on the monitoring system. If I understand you correctly, you place a network TAP between a system and the switch/router it was connected to and connected a second system to the monitor port of the TAP to see the packets.
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