New answers tagged firewall
1
vote
Accepted
Bypass nftables drop rule
Nitpicking: despite virbr0 being a bridge interface, this is about routing, not about bridging. The firewall happens on the routing side of the bridge: the bridge interface itself, not on the bridge ...
0
votes
How to Unban an IP properly with Fail2Ban
if you wish to find the IP first, you can do sudo fail2ban-client banned. This will show you the list of jails as well as the IPs inside them. Then you can either do sudo fail2ban-client unban <IP&...
2
votes
network unreachable for gcloud compute engine instance
As @john-hanley pointed out my home ISP doesn't support ipv6.
I never even thought this would be an issue, but on researching australian ISPs most still don't support v6.
0
votes
Suspicious process running under user postfix
The process is a standard part of Postfix – smtpd is literally the process that handles inbound SMTP connections. The path looks normal for a Postfix subprocess.
The connection looks like an inbound ...
0
votes
Change Cisco Management VLAN
From the route -n command it looks like the firewall isn't adding the VLAN tag so is that interface plugged into an access port on SW1? If so is that access port in the right VLAN?
Before you added ...
1
vote
AWS Network Firewall + Windows EC2 Instance - google.com is not blocked in browser but is blocked in the command line
It is more likely use of Encrypted Client Hello (ECH, formerly ESNI) with Server Name Indication (SNI) evasion.
The AWS Network Firewall only looks at the client-settable TLS SNI (comparable to the ...
0
votes
AWS Network Firewall + Windows EC2 Instance - google.com is not blocked in browser but is blocked in the command line
This is likely due to the fact that google uses QUIC and not always TLS. AWS Network Firewall has a limitation when inspecting TLS.
TLS inspection of UDP-based transport protocols such as Quick UDP ...
1
vote
Where does UFW (uncomplicated firewall) save command-line rules to?
On Ubuntu 16 and up user firewall rules are stored in /etc/ufw/user.rules and /etc/ufw/user6.rules. Overall all UFW rules and configs located in /etc/ufw
2
votes
Accepted
nftables rules can't ping to other server
Reasons it doesn't work
Reason 1: IPv6 NDP is dropped
The current ruleset prevents IPv6 to work properly on Ethernet, because it drops ICMPv6 traffic related to NDP which is the equivalent of ARP for ...
5
votes
Accepted
How to set iptables to block incoming requests to the server but still have internet connectivity
The added iptables rules prevent the system to access itself for its own services. If the DNS server is running on the system and queried using the host's main address or 127.0.0.1 then it can't be ...
Top 50 recent answers are included
Related Tags
firewall × 4270iptables × 991
linux × 649
networking × 583
security × 343
ubuntu × 230
windows × 220
port × 207
nat × 193
centos × 181
routing × 178
vpn × 173
cisco × 157
ufw × 157
router × 150
ssh × 138
pfsense × 123
windows-server-2008 × 117
linux-networking × 116
cisco-asa × 115
windows-firewall × 105
port-forwarding × 103
debian × 98
domain-name-system × 87
openvpn × 84