topic Re: IPCALC on CLI in General Topics

IPCALC on CLI

Kaspars_Zibarts — Wed, 14 Mar 2018 12:40:48 GMT

This migt be old news for some but definitely new news for myself

Ever wondered to quickly calculate network address, broadcast or mask from a host? Usually it's the online ipcalc but it actually lives in your GW. Good for scripting etc.

## SHOW MASK
[Expert@vsx]# ipcalc -m 190.160.3.100/28
NETMASK=255.255.255.240

## SHOW NETWORK ADDR
[Expert@vsx]# ipcalc -n 190.160.3.100/28
NETWORK=190.160.3.96

## SHOW BROADCAST ADDR
[Expert@vsx]# ipcalc -b 190.160.3.100/28
BROADCAST=190.160.3.111‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Re: IPCALC on CLI

AlekseiShelepov — Wed, 14 Mar 2018 13:34:17 GMT

I always used netcalc websites to verify mask and network address!

Commands can look like all-in-one:

# ipcalc -nmbp 192.168.1.34/28
NETMASK=255.255.255.240
PREFIX=28
BROADCAST=192.168.1.47
NETWORK=192.168.1.32

It works on Gaia and Splat, but not on IPSO.

Re: IPCALC on CLI

Kaspars_Zibarts — Wed, 14 Mar 2018 13:59:20 GMT

had to learn it after 15 years of using ipcalc online haha

Re: IPCALC on CLI

Danny — Wed, 14 Mar 2018 21:12:49 GMT

Looks like you stumbled upon Yuri Slobodyanyuk's blog post: Subnet calculator in Checkpoint – yurisk.info

Re: IPCALC on CLI

Gary_Lipets — Thu, 15 Mar 2018 18:51:09 GMT

A colleague of mine wrote a python script on a similar topic, the argument it expects is an output of "ifconfig -a" on a firewall. You will get all the locally attached subnets on the firewall, this might be useful to give to your vulnerability scanner to be able to scan all the DMZ's off the firewall

/////////////

#!/usr/bin/python

import sys

input_name = sys.argv[1]

with open(input_name, "r") as f:
contents = f.readlines()

for i, item in enumerate(contents):
if "inet addr:" in item and "Mask:" in item:
interface = contents[i - 1].split()[0]
cidr = 0
ip_octets = ((item.split("inet addr:")[1]).split()[0]).split(".")
subnet_mask_octets = ((item.split("Mask:")[1]).split()[0]).split(".")
for j, item in enumerate(subnet_mask_octets):
if item == "255":
cidr += 8
continue

elif item == "254":
cidr += 7

elif item == "252":
cidr += 6

elif item == "248":
cidr += 5

elif item == "240":
cidr += 4

elif item == "224":
cidr += 3

elif item == "192":
cidr += 2

elif item == "128":
cidr += 1

octet_number = j
octet_value = 256 - int(item)
break

ip_octets[octet_number] = str(int(ip_octets[octet_number]) // octet_value * octet_value)

for j in range(octet_number + 1, 4):
ip_octets[j] = "0"

print "%s/%s %s" %(".".join(ip_octets), cidr, interface)

////

Re: IPCALC on CLI

PhoneBoy — Thu, 15 Mar 2018 22:40:17 GMT

Had no idea we had that utility on Gaia.

Quite useful

Re: IPCALC on CLI

Kaspars_Zibarts — Fri, 16 Mar 2018 06:19:18 GMT

Haha great, then I don't feel left out..

Re: IPCALC on CLI

Oliver_Fink — Fri, 16 Mar 2018 09:47:18 GMT

I used ipcalc (different program) on my local Mac for years not knowing that it also exists on the firewall gateways. 😕