[sargandh:SARGANDH-3QLQC]$ git clone https://github.com/saravana815/scale_config_generator.git
[sargandh:SARGANDH-3QLQC]$ cd scale_config_generator
[sargandh:SARGANDH-3QLQC]$ python scale_config.py -h
usage: scale_config.py [-h] -f FILE -c COUNT [-o OUTFILE]

optional arguments:
  -h, --help                      show this help message and exit
  -f FILE, --file FILE            input config file
  -c COUNT, --count COUNT         number of times to scale the configs
  -o OUTFILE, --outfile OUTFILE   output file name for generated configs
[sargandh:SARGANDH-3QLQC]$

[sargandh:SARGANDH-3QLQC]$ cat config.txt

interface GigabitEthernet0/0/3.[2000]             # Number increment
 encapsulation dot1Q [2000]
 ip address 20.0.[0.2] 255.255.255.252            # IP address increment
 ip address 21.[0.0.2] 255.255.255.252 secondary  # IP address increment
 ip address [22.0.0.2] 255.255.255.252 secondary  # IP address increment
 ipv6 address 2001:[11AA:22BB]::2/64              # IPv6 address increment

[sargandh:bgl-ads-1214]$ ./scale_config.py
usage: scale_config.py [-h] -f FILE -c COUNT # -c number of iterations to run

[sargandh:SARGANDH-3QLQC]$ python scale_config.py -f config.txt -c 4
 interface GigabitEthernet0/0/3.2000
  encapsulation dot1Q 2000
  ip address 20.0.0.2 255.255.255.252
  ip address 21.0.0.2 255.255.255.252 secondary
  ip address 22.0.0.2 255.255.255.252 secondary
  ipv6 address 2001:11AA:22BB::2/64

 interface GigabitEthernet0/0/3.2001
  encapsulation dot1Q 2001
  ip address 20.0.0.3 255.255.255.252
  ip address 21.0.0.3 255.255.255.252 secondary
  ip address 22.0.0.3 255.255.255.252 secondary
  ipv6 address 2001:11AA:22BC::2/64

 interface GigabitEthernet0/0/3.2002
  encapsulation dot1Q 2002
  ip address 20.0.0.4 255.255.255.252
  ip address 21.0.0.4 255.255.255.252 secondary
  ip address 22.0.0.4 255.255.255.252 secondary
  ipv6 address 2001:11AA:22BD::2/64

 interface GigabitEthernet0/0/3.2003
  encapsulation dot1Q 2003
  ip address 20.0.0.5 255.255.255.252
  ip address 21.0.0.5 255.255.255.252 secondary
  ip address 22.0.0.5 255.255.255.252 secondary
  ipv6 address 2001:11AA:22BE::2/64

[sargandh:SARGANDH-3QLQC]$ ls -lh config_out.txt
-rwxrwxrwx 1 sargandh sargandh 474 Dec 21 22:11 config_out.txt
[sargandh:SARGANDH-3QLQC]$

[sargandh:SARGANDH-3QLQC]$ cat config2.txt

interface GigabitEthernet0/0/3.[2000,2,2002]    # Increment number from 2000 to 2002 by 2 for every iteration
 encapsulation dot1Q [2000,2,2002]
 ip address 20.0.[0.2,4] 255.255.255.252        # Increment IP address by 4 for every iteration
 ipv6 address 2001:[11AA:22BB,4]::2/64          # Increment IPv6 address by 4 for every iteration

[sargandh:SARGANDH-3QLQC]$ python scale_config.py -f config2.txt -c 4
interface GigabitEthernet0/0/3.2000
 encapsulation dot1Q 2000
 ip address 20.0.0.2 255.255.255.252
 ipv6 address 2001:11AA:22BB::2/64

interface GigabitEthernet0/0/3.2002
 encapsulation dot1Q 2002
 ip address 20.0.0.6 255.255.255.252
 ipv6 address 2001:11AA:22BF::2/64

interface GigabitEthernet0/0/3.2000
 encapsulation dot1Q 2000
 ip address 20.0.0.10 255.255.255.252
 ipv6 address 2001:11AA:22C3::2/64

interface GigabitEthernet0/0/3.2002
 encapsulation dot1Q 2002
 ip address 20.0.0.14 255.255.255.252
 ipv6 address 2001:11AA:22C7::2/64

[sargandh:SARGANDH-3QLQC]$