Symptoms

  1. All sites residing UI cluster does not work.
  2. Apache runs on every UI node and answers the URL requests.

  3. LB malfunctions - and does not allow to curl the website from cluster:

    [root@lb ~]# curl -k brand01.com
curl: (7) couldn't connect to host

  4. ipvsadm show no active connections with web servers:

    [root@lb ~]# ipvsadm -L
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
FWM  100 wlc persistent 900 mask 255.255.255.0
  -> 203.0.113.2:0              Route   32     0          0
  -> 203.0.113.3:0              Route   32     0          0
  5. Service iptables is stopped.

Cause

Stopped iptables service does not allow Load Balancer working properly as it contains the routing rules required for the functioning.

Resolution

Start iptables service:

/etc/init.d/iptables start

Internal content