[systemd-devel] networkd: Is auto-negotiation turned off when specifying parameters in a link file?
paulepanter at users.sourceforge.net
Thu Apr 2 04:11:30 PDT 2015
Dear systemd folks,
some network cards with certain cables and devices take up to five
seconds so that the link is up .
$ sudo journalctl -u systemd-networkd
-- Logs begin at Fr 2015-03-20 17:39:31 CET, end at So 2015-03-22 08:39:39 CET. --
Mär 20 17:39:31 myhostname systemd-networkd: lo : gained carrier
Mär 20 17:39:31 myhostname systemd-networkd: eth0 : link configured
Mär 20 17:39:34 myhostname systemd-networkd: eth0 : gained carrier
This is annoying if the system is up, but you cannot log into a server
because the NIC is so slow configuring the link.
The Linux kernel module developers from the e1000-devel mailing list
suggested the following :
> Both sides either need to be forced or both sides need to be auto-neg.
> Otherwise the auto-negotiation process will usually detect link (the
> physical signal) but fail to find duplex (since one side is not
> talking) and default to the lowest common denominator, e.g. half
> duplex. So, you could try forcing speed, it may look right on your
> end but if you have no visibility to the other end it could be running
> at half duplex.
> You may be able to speed up the auto negotiation process by
> exclusively advertising 1000 Mbps Full Duplex.
> # ethtool -s ethX advertise 0x20
In the IRC channel #systemd at irc.freenode.net somebody told me to look
into systemd’s network link configuration (`man systemd.link`).
Reading the manual page, it’s not clear to me, if auto-negotiation is
going to be disabled, if the following is set.
Is that equivalent to `ethtool -s ethX advertise 0x20`? If not, how
could I set that up?
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