[svlug] Raising network interface started to last too long

Steve Litt slitt at troubleshooters.com
Sun Sep 20 17:40:30 PDT 2015


On Sun, 20 Sep 2015 22:36:26 +0200
Ivan Sergio Borgonovo <mail at webthatworks.it> wrote:


> Now "Raising network interface" takes 50 sec, every time 50 sec.
> Now I'm addicted to nearly instant boot and I'd like to have it back.

> Any hint?

"Raising the network interface" can encompass a multitude of sins.
First, try replacing the "network interface raise" with something
like the following:

=======================================

#!/bin/sh
hostname -F /etc/hostname
ip link set dev lo up
ip link set dev eth1 down
ip addr add 192.168.100.88/24 dev eth1
ip link set dev eth1 up
ip route add default via 192.168.100.96

ping -c1 8.8.8.8

=======================================

I'd be willing to bet the preceding takes considerably less than 5
seconds. Obviously, replace ethy with the real device name, read by the
ip link command with no further args, and replace the IP addresses with
IP addresses relevant to your network.

Next, investigate any DHCP you're doing. *That's* what takes a lot of
time. My experience is more like a few seconds than 50, but it takes
significant time. If it's taking 50 and you're using systemd, perhaps
the computer is doing other things while it's waiting for that dhcp
lease, so the 50 seconds doesn't represent pure dhcp connection.

When you add wifi connectivity to DHCP connection time, things really
get slow.

I think experimentation will get you back to a 1 second static IP
connection, and a 15 second wifi+dhcp laptop connection.

SteveT

Steve Litt 
August 2015 featured book: Troubleshooting: Just the Facts
http://www.troubleshooters.com/tjust



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