When running the command iptables -vL you may find that :

• the output displays slowly.
• the output (appears) to have hung.

Solution

Due to IPtables trying to resolve the IP addresses to name you will need to add the -n switch to successfully list the chains. . The -n switch ensures the numeric output of addresses and ports. 

[root@linux ~]# iptables -nvL
Chain INPUT (policy DROP 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination
16500 1052K ACCEPT     all  --  *      *       0.0.0.0/0            0.0.0.0/0           state RELATED,ESTABLISHED
    1    52 ACCEPT     tcp  --  *      *       172.16.1.100         0.0.0.0/0           state NEW tcp dpt:9876
    0     0 ACCEPT     tcp  --  *      *       172.16.1.1           0.0.0.0/0           tcp dpt:80

!! remainder of output omitted !!