What is a firewall mark?

What is a firewall mark?

Firewall marks are an easy and efficient way to a group ports used for a protocol or group of related protocols. For instance, if LVS is deployed to run an e-commerce site, firewall marks can be used to bundle HTTP connections on port 80 and secure, HTTPS connections on port 443.

What is Netfilter mark?

Netfilter allows us to filter packets, or mangle their headers. One special feature is that we can mark a packet with a number. This is done with the –set-mark facility.

What is Mark in Conntrack?

Introduction. CONNMARK is a cool feature of Netfilter. It provides a way to have a mark which is linked to the a connection tracking entry. Once a connmark is set, it also apply for RELATED connection entry. So, if you add a connmark to an FTP connection, the same connmark will be put of connections from ftp-data.

What is mark in iptables?

The MARK target is used to set Netfilter mark values that are associated with specific packets. This target is only valid in the mangle table, and will not work outside there. Note that the mark value is not set within the actual package, but is a value that is associated within the kernel with the packet. …

What does IP route show?

The output of show ip route displays the entries in the routing table, as well as the means by which they were determined (directly connected network, static route, or which routing protocol was used to select the route).

What is Conntrack in Ubuntu?

DESCRIPTION. conntrack provides a full featured userspace interface to the netfilter connection tracking system that is intended to replace the old /proc/net/ip_conntrack interface. This tool can be used to search, list, inspect and maintain the connection tracking subsystem of the Linux kernel.

What is netfilter Conntrack?

The conntrack-tools are a set of tools targeted at system administrators. They are conntrack, the userspace command line interface, and conntrackd, the userspace daemon. The tool conntrack provides a full featured interface that is intended to replace the old /proc/net/ip_conntrack interface.

What does ip route flush do?

The flush option, when used with ip route empties a routing table or removes the route for a particular destination.

What is Prerouting and post routing?

PREROUTING: Immediately after being received by an interface. POSTROUTING: Right before leaving an interface. INPUT: Right before being handed to a local process. FORWARD: For any packets coming in one interface and leaving out another.

What is post routing?

PREROUTING (for altering packets as soon as they come in), OUTPUT (for altering locally-generated packets before rout‐ ing), and POSTROUTING (for altering packets as they are. about to go out).