nanog mailing list archives
Re: Value of linux net.ipv6.route.max_size
From: Toke Høiland-Jørgensen via NANOG <nanog () nanog org>
Date: Thu, 14 Mar 2024 16:09:22 +0100
Willy Manga <willym () manbene net> writes:
Hi, I recently noticed an issue with some routers complaining with that message: "kernel: Route cache is full: consider increasing sysctl net.ipv6.route.max_size." These routers are running FRR on Debian 12 , kernel 6.1.0-17-amd64. They are receiving full routing table and routes are inserted into the kernel routing table. I saw a similar error here [1] and it leads me to [2] as well but I should admit I did not read everything. I did not dive into the details of the two links but for now , I want to increase that value (and find the source of that error). The current value of net.ipv6.route.max_size is: 4096 . I guess it's the default on at least that kernel. For reference net.ipv4.route.max_size=2147483647 . Of course, we cannot correlate the two but I was wondering, what either people are using or what might be a reasonable value for the IPv6 counterpart.
The check (and error message) was removed entirely starting with kernel 6.3[0], so setting it to the same INT_MAX value as for IPv4 should probably be fine. The memory leak that mail thread you linked to references should have been fixed already in the kernel you're running (the fix[1] went in during the 5.16 cycle). -Toke [0] https://lore.kernel.org/all/20230112012532.311021-1-jmaxwell37 () gmail com/ [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=cdef485217d30382f3bf6448c54b4401648fe3f1
Current thread:
- Value of linux net.ipv6.route.max_size Willy Manga (Mar 14)
- Re: Value of linux net.ipv6.route.max_size Toke Høiland-Jørgensen via NANOG (Mar 14)