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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 ...
A.B's user avatar
  • 12.5k
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&...
NegassaB's user avatar
  • 101
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.
Brett Sutton's user avatar
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 ...
u1686_grawity's user avatar
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 ...
Adam Williams's user avatar
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 ...
new23d's user avatar
  • 21
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 ...
mcgoosh's user avatar
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
Aleksei Semidotskii's user avatar
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 ...
A.B's user avatar
  • 12.5k
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 ...
A.B's user avatar
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