CS & IT Solutions

How do I configure tables to drop large number of IPs?

Open pf.conf file, enter:

# nano /etc/pf.conf

Add following code:

table  persist file "/etc/pf.blocked.ip.conf"
ext_if="em1" # interface connected to internet

Add following code to drop and log all ips / subnet listed in /etc/pf.blocked.ip.conf, file

block drop in log (all) quick on $ext_if from  to any

Save and close the file. Now create file /etc/pf.blocked.ip.conf file using nano text editor, enter:

nano /etc/pf.blocked.ip.conf

Sample output:

192.168.1.0/24
202.54.1.5
# 202.54.4.5

The file /etc/pf.blocked.ip.conf should contain a list of IP addresses and/or CIDR network blocks, one per line. Any line beginning with # is treated as a comment and ignored by pf.

To load new rules, simply type:

# sh /root/reloadpf

How do I view all IP address listed in tables?

Type the following command
# pfctl -t blockedips -T show
Sample output:

58.65.232.0/21
58.83.12.0/22
64.28.176.0/20
64.255.128.0/19
66.231.64.0/20
67.213.128.0/20
69.8.176.0/20

How do I add subnet called 91.196.232.0/22 on the fly?

Use pfctl command itself, to add CIDR or IP on fly, enter:
# pfctl -t blockedips -T add 202.54.11.11
# pfctl -t blockedips -T add 91.196.232.0/22
How do I delete subnet called 91.196.232.0/22 on the fly?

Type the command as follows:
# pfctl -t blockedips -T delete 91.196.232.0/22
Please note that all changes made using pfct are dynamic. You need to update your file on disk to save the changes.
How do I see statistics for each IP / CIDR?

The -v option can display statistics for each table entry (IP/CIDR), enter:
# pfctl -t blockedips -T show -v
Sample output:

   216.243.240.0/20
        Cleared:     Thu Jul 10 03:01:01 2008
        In/Block:    [ Packets: 0                  Bytes: 0                  ]
        In/Pass:     [ Packets: 0                  Bytes: 0                  ]
        Out/Block:   [ Packets: 0                  Bytes: 0                  ]
        Out/Pass:    [ Packets: 0                  Bytes: 0                  ]
   216.255.176.0/20
        Cleared:     Thu Jul 10 03:01:01 2008
        In/Block:    [ Packets: 0                  Bytes: 0                  ]
        In/Pass:     [ Packets: 0                  Bytes: 0                  ]
        Out/Block:   [ Packets: 0                  Bytes: 0                  ]
        Out/Pass:    [ Packets: 0                  Bytes: 0                  ]

How do I view log of dropped IP from default /var/log/pflog file?

Use tcpdump command to read a log file:
# tcpdump -n -e -ttt -r /var/log/pflog
# tcpdump -n -e -ttt -r /var/log/pflog port 80
# tcpdump -n -e -ttt -r /var/log/pflog and host 202.33.1.2
You can also view log in real time, enter:
# tcpdump -n -e -ttt -i pflog0
# tcpdump -n -e -ttt -i pflog0 port 80
# tcpdump -n -e -ttt -i pflog0 host 202.33.1.2

source here