Squids

DNS and squid

• to add new IPs for squid:
  • add the IPs in /var/named/master/wikipedia.zone in the obvious places (on zwinger)
  • make sure to update the serial number in the zone file!
  • run rndc reload to make it update - no need to restart named

• for 3 squids - use 6 IPs, to allow even load-balancing if 1 or 2 squids go down
• 2 scripts in /home/wikipedia/bin:
  • takeip
  • dropip (vapourware)

• some useful commands:
  • dig ANY en.wikipedia.org @zwinger.wikipedia.org
  • dig +short ANY en.wikipedia.org

Virtual IPs

browne:    207.142.131.235, 207.142.131.247
coronelli: 207.142.131.236, 207.142.131.248
maurus:    207.142.131.245, 207.142.131.246

• According to damyta, should use 255.255.255.255 for netmask for the IPs of virtual eth interfaces - otherwise there can be routing confusion.
• You must ping through the switch via a virtual interface which you have just brought up (using ping -I), to update the switch's idea of who has what IP. When pinging with -I207.142.131.248 or similar, use suda as the ping target; pinging the broadcast address does not always work.
  • Can use script takeip in /h/w/bin to take over an IP if a squid goes down.
  • To take down a virtual eth interface, /sbin/ifconfig eth0:n down
  • TODO: set up heartbeat for automatic IP takeover.