4,442 reputation
612
bio website systemajik.com
location Gatineau, Canada
age 59
visits member for 3 years, 10 months
seen 10 hours ago
I have over 30 years experience in all phases of software development and delivery. I have administered a variety of midrange servers, and worked with systems from PCs to Mainframes.

Jul
2
comment IPv6 in IPv4 over LAN
Route filtering?
Jul
2
comment IPv6 in IPv4 over LAN
@bahamat I am fully aware that fixed NAT does not provide any security. The use of private (non-Internet routeable) addresses does provide security in the absence of any incoming NAT rules. The stateful source NAT typically used for IP masquerading in this case tends to be secure, and to the best of my knowledge is not Linux specific. Firewalling does not provide private addesses access to the Internet, NAT does. I'll leave it at that.
Jul
2
comment IPv6 in IPv4 over LAN
@bahamat I think you are confusing connection tracking for a IP Masquerading (which enables hosts on private addresses to connect to the Internet) with connection tracking for firewalling. IP Masquerading is not firewalling, but both can use the same connection tracking data. DNAT which is not IP Masquerading can be used to pass in through the firewall.
Jun
30
comment IPv6 in IPv4 over LAN
@bahamat On the stateful NAT configurations I have used if you can craft the right packets, you are likely already passing through. The firewall further limits which port can pass in or out.
Jun
30
comment IPv6 in IPv4 over LAN
@bahamat NAT to private addresses does prevent direct access to the devices behind it (except for those that are port forwarded to). As such it is an effective firewall for incoming connections. IPv6 does not offer such protection.
Jun
29
answered IPv6 in IPv4 over LAN
Jun
28
answered How to initiate SMTP outbound traffic via secondary interface - Linux Sendmail
Jun
28
answered Traffic stats per network port
Jun
26
comment CPU stuck at 99% for a few hours. Really need help figuring out logs
If you end up with multiple cleanup processes running, they may interfere with each other by generating locks on the directory when they delete files. Try temporarily removing it from the crontab until the load clears. Then add it with a longer interval between runs. You may want to move it to a script with a locking mechanism to ensure only one instance is running. Kill off any multiple instances of the command for now.
Jun
20
answered How to clean up the RAM memory that is being used as cache memory?
Jun
14
awarded  Enlightened
Jun
14
awarded  Nice Answer
Jun
5
reviewed Reject Can't ping broadcast
Apr
27
revised Reverse DNS lookups slowing down network operations on LAN
Add self-discovery options.
Apr
27
revised Reverse DNS lookups slowing down network operations on LAN
Clarify response.
Apr
27
answered Reverse DNS lookups slowing down network operations on LAN
Apr
24
answered How to completely hide stuff from a user?
Apr
19
answered Find out network traffic per IP
Apr
16
comment Using a secondary DNS when lookup fails in primary?
dnsmasq can be configured to resolve different domains form different servers quite easily.
Apr
6
answered What's the best strategy to catch mystery process?