Hello, I am new to P4, and I have implemented several small projects using VMware, Mininet, bmv2 switch, and P4, all the previous “tools”(except VMware) are running on Ubuntu 22.04.3 LTS. During my tests, I saw that the bmv2 switch processes ethernet packets without problems up to Layer 3. For exa…

inside your action, I think you need to update the ethernet.dstAddr to point to the MAC address of the host h2. to do so, you need to add another parameter to your action, and set its value from the control plane in a similar way to how you are setting the egress spec. probably the ethernet interf…

Thanks for responding and providing your inside. [tcp_packet_not_sent] So, I am uploading 2 figures that I hope u can see(if not, they are in Drive: P4 and BMV2 errors - Google Drive ) My code defines a table to pass the packets from one interface to another, it does not filter anything, in the…

A switch, whether P4-programmable or not, typically does not get involved in the TCP protocol except by forwarding packets to the proper destination host. Your P4 program does not even mention TCP, which should mean that as long as the logic of your program is not dropping packets, or sending them …

Hello Andy, I am so Glad you commented. Yes, my P4 program is doing nothing to the TCP header, I have another program that does it, but because it was not working I decided to test it in the simplest way possible with the program I provided before. The program provided just passes the traffic from…

Sorry for the late reply, a wireshark capture is very helpful in diagnosing this kind of problems. my second assumption is that you have hardware offload enabled which leaves the checksum calculations to the network card. However, as your packets are going through virtual interfaces this is never …

If your P4 program is ignoring the value of the IP protocol field, then it should be processing packets identically regardless of whether they are ICMP, TCP, UDP, etc. That is a good thing when you are trying to simplify your debugging life, as it should not matter (at least not to the P4 switch) w…

It WORKED!!! Thank u Faris, I had to deactivate the “checksum offloading”, and that solved the problem!!! More information how to do it can be found here: [image] Help needed disabling TCP/UDP checksum offloading in Debian Hi Guys, I'm running the latest, fully patched release of debia…

Yeah, it was also my post… I did not see it until now… Thank u, the problem was solved turnning off “checksum offloading”. I will continue testing the granilarity that P4 offers in next months and If I find any challenge on my way I will be back here. This the TCP program BTW, now working with no…

TCP packets are not being processed correctly by bmv2

Getting Started with P4

andyfingerhut January 18, 2024, 9:58am 8

Searching for “checksum offload” in this web forum I found this post, which might be helpful: Connect mininet hosts to root namespace - #10 by Sally

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TCP packets are not being processed correctly by bmv2

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