[CentOS] Centos Router

[Graham Johnston]

On Tue, 2007-09-11 at 13:43 -0400, Ken Price wrote:
> >> My best tip for tuning performance:
> >>
> >> Don't until performance becomes an issue otherwise you have no
> >> basis of determining whether performance has improved.
> >
> > Let me add a second tip:
> >
> > Don't tune a parameter unless you know what is does.
> >
> 
> While probably not popular, those are very good tips.
> 
> I can give you some comparative performance info using CentOS3 and  
> CentOS4.  CentOS5 will probably give equal or slightly better  
> performance depending on specific configurations.
> 
> Harware:
> 4 Dell PowerEdge 350's (2 routers, 2 NAT firewalls)
> PIII-850
> 512 Mb RAM
> 
> Bandwidth:
> Average 25-35Mbps
> Peak 80Mbps sustained for 1-2 hours
> 10k-25k connections
> 
> NAT Firewall:
> CPU usage approx 2-8%
> 
> Router:
> CPU usage approx 2-4%
> 
> With the above specs, I was approaching the connection threshold with  
> 512Mb RAM (32768 = theoretical max) and beginning to drop connections.  
>   This was quickly fixed by adding an additional 512Mb RAM and  
> adjusting the CONNTRACK_MAX accordingly.
> 
> Hope this helps.  All boxes were running Keepalived for failover.   
> Fairly straight forward routing so no software used except routing  
> tables, IP, and IP forwarding.
> 
> Hope this helps!
> -Ken
> 

Ken,

In your configuration did you tune any sysctl settings or leave with
defaults?

Graham Johnston
Manager, Network Services
Westman Communications Group
204.571.7225
johnstong at westmancom.com