7. Dimensioning¶
The maximum numbers for NAT entries, CPEs (users), conntracks (sessions), blocks and block sizes are defined in the configuration. These capabilities can be adjusted to adapt to the amount of memory available in the system.
The following table shows a list of different capability combinations and the corresponding memory requirement. This is empirical and may have to be tuned according to your use case.
Max conntracks |
Max nat entries |
Max cpe |
Max blocks |
Required memory |
|---|---|---|---|---|
1M |
1M |
10K |
80K |
5 GB |
2M |
2M |
20K |
80K |
6 GB |
4M |
4M |
20K |
80K |
8 GB |
8M |
8M |
20K |
80K |
12 GB |
16M |
16M |
20K |
80K |
24 GB |
30M |
30M |
20K |
80K |
32 GB |
Here is an example to change the maximum number of conntracks.
vrouter> edit running
vrouter running config#
vrouter running config# system fast-path limits cg-nat max-conntracks 2000000
vrouter running config# commit
Modifying capabilities will automatically restart the fast path and interrupt packet processing. To check that the fast path is back up and running, use the following command.
vrouter running config# show state system fast-path
fast-path
enabled stopping
..
vrouter running config# show state system fast-path
fast-path
enabled starting
..
vrouter running config# # show state system fast-path
fast-path
enabled true
...