Red Hat Enterprise Linux -beta: Configuring Firewalls and Packet Filters

Red Hat Enterprise Linux (RHEL) 10-beta introduces advanced firewall and packet filtering capabilities, including firewalld, nftables, and XDP (eXpress Data Path) for high-performance packet processing. This guide covers key configurations, commands, and best practices.

You Should Know:

1. Managing `firewalld` Service

`firewalld` is the dynamic firewall manager in RHEL. Key commands:

• Start/Enable firewalld:

  sudo systemctl start firewalld 
  sudo systemctl enable firewalld 
  

• Check Status:

  sudo firewall-cmd --state 
  

• Allow HTTP/HTTPS Traffic:

  sudo firewall-cmd --permanent --add-service=http 
  sudo firewall-cmd --permanent --add-service=https 
  sudo firewall-cmd --reload 
  

• Block an IP Address:

  sudo firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="192.168.1.100" reject' 
  sudo firewall-cmd --reload 
  

2. Configuring `nftables` Framework

`nftables` replaces `iptables` in RHEL 10-beta for efficient packet filtering.

• Install & Start:

  sudo dnf install nftables 
  sudo systemctl enable --now nftables 
  

• Basic Rule to Allow SSH:

  sudo nft add table inet filter 
  sudo nft add chain inet filter input { type filter hook input priority 0 \; } 
  sudo nft add rule inet filter input tcp dport 22 accept 
  

• Save Rules Permanently:

  sudo nft list ruleset > /etc/nftables.conf 
  

3. XDP (eXpress Data Path) Packet Filtering

XDP allows ultra-fast packet processing at the kernel level.

• Load XDP Program:

  sudo ip link set dev eth0 xdp obj xdp_filter.o sec .text 
  

• Verify XDP Attachment:

  ip link show eth0 
  

• Drop Specific Packets (BPF Code Snippet):

  SEC("xdp") 
  int xdp_drop(struct xdp_md ctx) { 
  return XDP_DROP; 
  } 
  

What Undercode Say:

RHEL 10-beta strengthens network security with firewalld, nftables, and XDP. Key takeaways:
– Use `firewall-cmd` for dynamic rule management.
– Migrate from `iptables` to `nftables` for better performance.
– Leverage XDP for DDoS protection and low-latency filtering.

Additional Commands:

• Check Open Ports:

  sudo ss -tulnp 
  

• Monitor Traffic:

  sudo tcpdump -i eth0 -n 
  

• Kernel Logs for XDP Errors:

  sudo dmesg | grep XDP 
  

Expected Output:

A secure, high-performance firewall setup in RHEL 10-beta with firewalld, nftables, and XDP integration.

References:

Reported By: Maaouiaadem Red – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅

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