[c-nsp] Cisco SLB Capacity

[lists at hojmark.org]

> I have to configure SLB for one customer to balance traffic 
> (SMTP) between two mail servers. Customer has two C6500 with 
> sup720 running 12.2(18)SXD. Has anybody done a similar 
> configuration and want to share his experience with me? 

I've used if for load-balancing at least HTTP, SMTP, MS RDP and
probably others that I don't currently remember.

> I'm using HSRP between the two cat's: is is possible to use 
> any kind of redundancy with the virtual ip address to have a
> backup?

Sure. Do something like this.

ip slb serverfarm MAILFARM
 nat server 
 real 10.11.12.13
  inservice 
 real 10.11.12.14 
  inservice 

ip slb vserver MAILVSERVER
 virtual 10.11.14.1 tcp 25
 serverfarm MAILFARM
 inservice standby MAILSERVERVLAN

int Vlan10 
 desc *** Server-VLAN *** 
 ip addr 10.11.12.2 255.255.255.0 
 standby ip 10.11.12.1 
 standby name MAILSERVERVLAN

And see the documentation (http://tinyurl.com/al84j), it's
actually quite good.

> I'm also worried about the maximum number of connections that 
> is able to support without affecting all the other services.  

Well it's not meant for heavy duty load-balancing, but for
something like mail I wouldn't be too worried. If you need more
performance and functionality than that, look at the CSM or a
stand-alone L5 switch.

-A