On mar. 3 déc. 09:40:31 2019, Vincent Bernat wrote:
> So, there is 0x56 entries in the cache. Isn't that clear? :)
>
> https://elixir.bootlin.com/linux/latest/source/net/ipv6/route.c#L6006
I did a quick test on some routers:
core01-arendal, no fullview, on my own ASN, no so much traffic, using
tunnels
https://pix.milkywan.fr/apWaD84h.png
core01-arendal ~ # while :; do awk --non-decimal-data '{ print
("0x"$6)+0, "(" $6 ")" }' /proc/net/rt6_stats; sleep 120; done
86 (0056)
86 (0056)
86 (0056)
core01-arendal ~ # ip -6 r | wc -l
64
core01-arendal ~ # uname -a
Linux core01-arendal.no.swordarmor.fr 4.19.86-gentoo #1 SMP Mon Dec 2
19:02:33 CET 2019 x86_64 AMD GX-412TC SOC AuthenticAMD GNU/Linux
core02-arendal, no fullview, on my own ASN, no so much traffic, using
tunnels
https://pix.milkywan.fr/NF3jNY9K.png
core02-arendal ~ # while :; do awk --non-decimal-data '{ print
("0x"$6)+0, "(" $6 ")" }' /proc/net/rt6_stats; sleep 120; done
28 (001c)
30 (001e)
30 (001e)
core02-arendal ~ # ip -6 r | wc -l
39
core02-arendal ~ # uname -a
Linux core02-arendal.no.swordarmor.fr 4.19.86-gentoo #1 SMP Mon Dec 2
22:08:21 CET 2019 x86_64 AMD G-T40E Processor AuthenticAMD GNU/Linux
edge01-terrahost, fullview, on my own ASN, no so much traffic, using
one tunnel
https://pix.milkywan.fr/6AVwYkY8.png
edge01-terrahost ~ # while :; do awk --non-decimal-data '{ print
("0x"$6)+0, "(" $6 ")" }' /proc/net/rt6_stats; sleep 120; done
96 (0060)
101 (0065)
101 (0065)
edge01-terrahost ~ # ip -6 r | wc -l
77439
edge01-terrahost ~ # uname -a
Linux edge01-terrahost.no.swordarmor.fr 4.19.82-gentoo #2 SMP Tue Nov
12 22:08:28 CET 2019 x86_64 Intel(R) Core(TM) i5-3470 CPU @ 3.20GHz
GenuineIntel GNU/Linux
edge02-fjordane, fullview, on my own ASN, no so much traffic, using
one tunnel
https://pix.milkywan.fr/J4rOuylq.png
edge02-fjordane ~ # while :; do awk --non-decimal-data '{ print
("0x"$6)+0, "(" $6 ")" }' /proc/net/rt6_stats; sleep 120; done
110 (006e)
110 (006e)
110 (006e)
edge02-fjordane ~ # ip -6 r | wc -l
77433
edge02-fjordane ~ # uname -a
Linux edge02-fjordane.no.swordarmor.fr 4.19.86-gentoo #1 SMP Thu Nov 28
16:47:53 CET 2019 x86_64 Common KVM processor GenuineIntel GNU/Linux
regis, fullview, on my own ASN, a bit more traffic, using one tunnel
https://pix.milkywan.fr/5XeaK2du.png
regis ~ # while :; do awk --non-decimal-data '{ print ("0x"$6)+0, "("
$6 ")" }' /proc/net/rt6_stats; sleep 120; done
0 (0000)
1 (0001)
1 (0001)
regis ~ # ip -6 r | wc -l
77538
regis ~ # uname -a
Linux regis.swordarmor.fr 4.14.83-gentoo #2 SMP Sat Feb 2 16:50:41 CET
2019 x86_64 Intel(R) Xeon(R) CPU X3450 @ 2.67GHz GenuineIntel GNU/Linux
asbr02, fullview, on a not-for-profit ASN providing services for others,
100M of traffic, using one tunnel
https://pix.milkywan.fr/l1hfAAIn.png
alarig@asbr02 ~ $ while :; do awk --non-decimal-data '{ print
("0x"$6)+0, "(" $6 ")" }' /proc/net/rt6_stats; sleep 120; done
4 (0004)
3 (0003)
0 (0000)
alarig@asbr02 ~ $ ip -6 r | wc -l
77525
alarig@asbr02 ~ $ uname -a
Linux asbr02.cogent-rns.grifon.fr 4.14.156-gentoo #1 SMP Tue Dec 3
09:53:23 CET 2019 x86_64 Intel(R) Xeon(R) CPU X3450 @ 2.67GHz GenuineIntel
GNU/Linux
So, I have more routes in cache than in FIB on my two core routers, I’m
pretty sure there is a bug there :p
I have less routes in cache on 4.14 kernels but more traffic.
I don’t know which function is feeding the cache, but I think that it’s
doing too much.
--
Alarig
