Messages in this thread | | | From | "Xiao, Jiguang" <> | Subject | RE: This counter "ip6InNoRoutes" does not follow the RFC4293 specification implementation | Date | Thu, 24 Feb 2022 09:04:01 +0000 |
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Hi David
Thanks for guiding me how to proceed. I have captured the output result of perf (perf_output_5.10.49).
To confirm the problem, I tested it again on Ubuntu (kernel version is 5.4.0-79) using Docker and the results were the same, the only difference is the kernel version. I also collected the perf results and added them to the attachment (perf_output_5.4.0).
Best Regards Xiao Jiguang
-----Original Message----- From: David Ahern <dsahern@kernel.org> Sent: 2022年2月17日 11:00 To: Xiao, Jiguang <Jiguang.Xiao@windriver.com>; davem@davemloft.net; yoshfuji@linux-ipv6.org; kuba@kernel.org; netdev@vger.kernel.org; linux-kernel@vger.kernel.org Subject: Re: This counter "ip6InNoRoutes" does not follow the RFC4293 specification implementation
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On 2/16/22 3:36 AM, Xiao, Jiguang wrote: > Hello, > > I found a counter in the kernel(5.10.49) that did not follow the > RFC4293 specification. The test steps are as follows: > > > > Topology: > > |VM 1| ------ |linux| ------ |VM 2| > > > > Steps: > > 1. Verify that “VM1” is reachable from “VM 2” and vice versa using > ping6 command. > > 2. On “linux” node, in proper fib, remove default route to NW address > which “VM 2” resides in. This way, the packet won’t be forwarded by > “linux” due to no route pointing to destination address of “VM 2”. > > 3. Collect the corresponding SNMP counters from “linux” node. > > 4. Verify that there is no connectivity from “VM 1” to “VM 2” using > ping6 command. > > 5. Check the counters again. > > > > The test results: > > The counter “ip6InNoRoutes” in “/proc/net/dev_snmp6/” has not > increased accordingly. In my test environment, it was always zero. > > > > My question is : > > Within RFC4293, “ipSystemStatsInNoRoutes” is defined as follows: > > “The number of input IP datagrams discarded because no route could > be found to transmit them to their destination.” > > Does this version of the kernel comply with the RFC4293 specification? > >
I see that counter incrementing. Look at the fib6 tracepoints and see what the lookups are returning:
perf record -e fib6:* -a <run test> Ctrl-C perf script [unhandled content-type:application/octet-stream][unhandled content-type:application/octet-stream] | |