Scenario
KELP Coastal Radio streams from a single edge router,
KELP-BORDER. Since Saturday, three internet hosts
have been hammering the public stream with junk requests. Until your
upstream provider sets up scrubbing, block those three sources at the
border and let every other host keep listening.
Block these sources:
203.0.113.58 ·
198.51.100.244 ·
192.0.2.17
Use standard ACL 40, permit all other traffic, and apply it
inbound on the WAN interface
GigabitEthernet0/1. This is temporary — no need
to save the config.
Tasks — auto-checked
Check your understanding