# This file is part of systemd.

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#

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# systemd is free software; you can redistribute it and/or modify it

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# under the terms of the GNU Lesser General Public License as published by

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# the Free Software Foundation; either version 2.1 of the License, or

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# (at your option) any later version.

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# See sysctl.d(5) and core(5) for documentation.

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# To override settings in this file, create a local file in /etc

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# (e.g. /etc/sysctl.d/90-override.conf), and put any assignments

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# there.

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# System Request functionality of the kernel (SYNC)

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#

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# Use kernel.sysrq = 1 to allow all keys.

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# See https://www.kernel.org/doc/html/latest/admin-guide/sysrq.html for a list

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# of values and keys.

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kernel.sysrq = 16

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# Append the PID to the core filename

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kernel.core_uses_pid = 1

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# https://bugzilla.redhat.com/show_bug.cgi?id=1689346

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kernel.kptr_restrict = 1

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# Source route verification

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net.ipv4.conf.all.rp_filter = 1

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# Do not accept source routing

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net.ipv4.conf.all.accept_source_route = 0

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# Promote secondary addresses when the primary address is removed

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net.ipv4.conf.all.promote_secondaries = 1

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# ping(8) without CAP_NET_ADMIN and CAP_NET_RAW

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# The upper limit is set to 2^31-1. Values greater than that get rejected by

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# the kernel because of this definition in linux/include/net/ping.h:

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# #define GID_T_MAX (((gid_t)~0U) >> 1)

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# That's not so bad because values between 2^31 and 2^32-1 are reserved on

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# systemd-based systems anyway: https://systemd.io/UIDS-GIDS.html#summary

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-net.ipv4.ping_group_range = 0 2147483647

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# Fair Queue CoDel packet scheduler to fight bufferbloat

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net.core.default_qdisc = fq_codel

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# Enable hard and soft link protection

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fs.protected_hardlinks = 1

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fs.protected_symlinks = 1

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