What are Wild Card Masks?

• Are used with the host/network address to tell the router a range of addresses to filter

• Examples:

  • To specify a host:
    • 196.200.220.1 0.0.0.0
  • To specify a small subnet:
    • 196.200.220.8 – 196.200.220.15 (would be a /29)
    • Block size is 8, and wildcard is always one number less than the block size
    • Cisco access list then becomes 196.200.220.8 0.0.0.7
  • To specify all hosts on a /24 network:
    • 196.200.220.0 0.0.0.255

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