一些手記

修改20161027

Linux

可以對介面產生UUID：uuidgen eth0

查詢某個未安裝指令的軟體(red hat)：yum provides \*/bin/<command>
查看網路介面上的封包：tcpdump -nni eth0 -vvv
產生公鑰、私鑰：ssh-keygen -t rsa -b 4096

用linux轉發封包

查詢是否能轉發

sysctl net.ipv4.ip_forward

or

cat /proc/sys/net/ipv4/ip_forward

改成可轉發

sysctl -w net.ipv4.ip_forward=1

or

echo 1 > /proc/sys/net/ipv4/ip_forward

修改開機後可轉發

在/etc/sysctl.conf裡，修改net.ipv4.ip_forward = 1

sysctl -p /etc/sysctl.conf

重啟服務/etc/init.d/procps.sh restart

Shell Script

[ 0 -eq 0 ] && ${echo 'yes'; echo 'yes2’;} || echo 'no'; #bad substitution

[ 0 -eq 0 ] && `echo 'yes'; echo 'yes2';` || echo 'no'; #持續輸出yes2

[ 0 -eq 0 ] && (echo 'yes'; echo 'yes2';) || echo 'no'; #輸出yes和yes2

Juniper

讓管理權限使用者perry可以用public key做ssh connection(不需密碼)

set system login user perry uid 2000

set system login user perry class super-user

set system login user perry authentication ssh-rsa "ssh-rsa AAAAB3NzaC1yc2EAAAADAQGJIAABAQDAdZ/VeeKUqAvwmopVNy1murzqeoObxcNtSnwMR3jWXZyiW3O29rBPZqYuj5u4VuutceW/ETirDmo7UKlIKFgploeyhFfyfTStNfdZL4QqwadsUFePMeCe41jW+ez2nV1UFAiGcvyhzfJSVAGm2i80cKeAHdO3vjpYR+aBib3VFYxl2B/y4oJijEOCmmWnwZFTNBkI2xX0EmZYiVOgs9G1ztplPdGq+1Km03TB/g5C+2Fm7cYhs9igbZmD5Pr5dhvX10CHV6FFw3tLGDtJJhYs/bvYVaRTJAArh+9erRkECvIvBCywPSdcm9K3dT2fAaTqNhyb3LW4Wi9Yk3nd7Evb test@example.com;”