Network issue - asynchronous routing

For my purposes, I need to use asynchronous routing. Since version 8.6, asynchronous routing with TCP stopped working, if I boot the previous kernel 4.18.0-348.12.2.el8_5.x86_64, then asynchronous routing works well. How to enable asynchronous routing in version of the kernel 4.18.0-372.9.1.el8.x86_64?

Welcome @Maksym ! It looks like this issue is reported by someone else to the upstream. In the meantime, I’ll post to the development team and see if they have a workaround other than booting to the previous kernel.

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Looks like this issue is still being investigated by the upstream. Your only recourse at the moment is to boot to the older kernel. From the RHEL issue:

“…8.6.0 contained a bug that caused connection tracking to fail in some cases, e.g. asymetric routing”

Hopefully, the kernel will be patched in an upcoming update.

Good Luck!

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Thanks for posting your issue. I depend on asymmetric routing for the HA firewall/routers that I have deployed. Anyone know if this affects ipv4 also? I don’t use ipv6. I am also using iptables rules still and just letting them get translated with the compat stuff.

Someone responded in Chat that it does affect ipv4 also. I can’t see the redhat bug so I am not sure what the workaround would be or why it would work.

On the new kernel 4.18.0-372.13.1.el8_6.x86_64 the problem is resolved!

Thanks for the info on it being resolved. Was it tested as fixed? The redhat bugzilla article doesn’t mention an update fixed it. It still says it is being investigated.

I found it mentioned in that kernel update as you suggested… it looks like they referenced an internal private bug # instead of the public one.

“weird port mapping with asymmetric traffic (BZ#2065266)”