Ravi Sir's Cards › AWS
Host vs network firewall
This revision card explains Host vs network firewall. It starts from the need that one layer alone leaves gaps peers can abuse. It describes host = OS tools (iptables/nft/firewalld/ufw); Network = path for many hosts (SG, NF, NGFW). The how-to section notes bastion keeps host FW even inside a tight SG; tiers use network FW. An example on the card is omar Haddad locks SSH on the bastion with ufw and SG together.
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What this card says
Why do we need it?
One layer alone leaves gaps peers can abuse.
What is it?
Host = OS tools (iptables/nft/firewalld/ufw); Network = path for many hosts (SG, NF, NGFW).
host-based
How to do it
Bastion keeps host FW even inside a tight SG; tiers use network FW.
Example
Omar Haddad locks SSH on the bastion with ufw and SG together.