IPアドレスをログオン前に表示

現代的な方法
https://qiita.com/yunano/items/8363c6770c00e339f5eb

# mv mv /etc/issue /etc/issue.org
# cat  /etc/NetworkManager/dispatcher.d/show-ip-address
#!/bin/sh

cp /etc/issue.org /etc/issue
echo 'IP addresses:' >> /etc/issue
echo $(hostname -I) >> /etc/issue
echo '' >> /etc/issue

# chmod +x /etc/NetworkManager/dispatcher.d/show-ip-address
# bash /etc/NetworkManager/dispatcher.d/show-ip-address

簡易な方法

/etc/issue
My IP address: \4

/etc/rc.localに以下を追加

if [ ! -f /etc/issue.org ]; then
    /bin/cp /etc/issue /etc/issue.org
fi
/bin/cp -f /etc/issue.org /etc/issue
/sbin/ifconfig eth0 | /bin/grep "inet addr" >> /etc/issue

当然のことながらDHCP環境等、頻繁に変わる場合は変更されている可能性がある。