SSH Piping between remote servers

SSH is without doubt my favourite command line tool. Today I needed to transfer a file between two hosts that I could SSH to, but could not SSH to each other. This is really simple with a bit of standard UNIX piping.

ssh hostA cat somescript.sh | ssh hostB "cat > somescript.sh"

Job done.

iproute2 cheat sheet

Ok so apparently ifconfig is either deprecated or old fashioned and your supposed to use the 'ip' command instead. Turns out it's really nice and I prefer it to ifconfig,route,already.

Here's some examples:

ip addr - equivalent to ifconfig

ip addr show eth0 - same as above just show eth0

ip ro - show routing table

ip route add default via 192.168.0.254 - set the default gateway

ip addr add 192.168.0.5/24 brd + dev eth0 label eth0:0 - set an ip alias on eth0 and call it eth0:0

ip neigh - show the arp table

Disable a yum repository while running yum update

I wanted to run all updates from the RHEL repositories, but not the rpmforge and WAN Disco ones. Easy.

sudo yum check-update --disablerepo=rpmforge --disablerepo=WANdisco-dev