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I'm trying to reconfigure some network kernel settings at /proc/sys/net/core in my container. But it seems some options are missing in docker ubuntu:14.04 so that i can't configure them. example:

$ sysctl -w net.core.rmem_max=262144
sysctl: cannot stat /proc/sys/net/core/rmem_max: No such file or directory

There're just a few options in my docker:

In my Host's Ubuntu:

$ ls /proc/sys/net/core/
bpf_jit_enable         message_burst           rmem_default           xfrm_acq_expires
busy_poll              message_cost            rmem_max               xfrm_aevent_etime
busy_read              netdev_budget           rps_sock_flow_entries  xfrm_aevent_rseqth
default_qdisc          netdev_max_backlog      somaxconn              xfrm_larval_drop
dev_weight             netdev_rss_key          warnings
flow_limit_cpu_bitmap  netdev_tstamp_prequeue  wmem_default
flow_limit_table_len   optmem_max              wmem_max

In my docker's Ubuntu:

$ ls /proc/sys/net/core/
somaxconn  xfrm_acq_expires  xfrm_aevent_etime  xfrm_aevent_rseqth  xfrm_larval_drop

I attempted to run docker with --net=none/default (I don't wanna use host) or --v /proc/sys/net:/proc/sys/net but nothing changes.

I read this from kernel.org: "/proc/sys/net ... You may see only some of them, depending on your kernel's configuration."

So is there any way to get fully options?

Thanks!

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Those files represent configuration of your host network stack, without --net=host you create a new network stack inside a container and files are 'overwritten' by container ones.

If you need access to host stack you might consider mounting it somewhere else, lets say /net using -v /proc/sys/net/:/net and then simply use echo value > /net/my/file instead of using sysctl.

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  • I mounted as you suggested but the files in /net/core are still the same with /proc/sys/net/core in the container other than the host. Furthermore, I want to change setting of NIC of container but not host's NIC. because I am trying to install a package that requires to change those files on container.
    – asker
    Sep 12 '15 at 17:51
  • Remeber that you have only a virtual link inside a container, not a physical one. Most probably by modifying host NIC you will have expected behaviour inside container ( I am not sure about it though ).
    – Łukasz
    Sep 12 '15 at 22:57

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