topic Status-Tracking on ACE in Application Networking

Status-Tracking on ACE

martin.foote — Tue, 26 Oct 2010 16:39:07 GMT

Hello

On the CSM there was a feature called status tracking, it's description:

Router(config-module-csm)# vserver 
dependent_virtserver_name

Identifies the dependent virtual server and enters the virtual server configuration mode.

Router(config-slb-vserver)# 
virtual ip-address [ip-mask] 
protocol port-number [service {ftp 
| rtsp | termination}]

Sets the IP address for the dependent virtual server optional port number or name and the connection coupling and type². The protocol value is tcp, udp, any (no port number is required), or a number value (no port number is required).

Router(config-slb-vserver)# 
status-tracking 
tracked_virtserver_name

Identifies the tracked virtual server. When this virtual server is taken out of service or fails, the dependent virtual server identified in Step 1 is automatically taken out of service.

From http://www.cisco.com/en/US/docs/interfaces_modules/services_modules/csm/4.2.x/configuration/guide/mapolcy.html

I am wondering if anyone knows of a similar feature in ACE?

The additional complexity is now the dependant vserver and tracked vserver are in different ACE contexts, does anybody know if there is way to track vservers in a different context?

Got to admit I'm relatively new to ACE but hope this makes sense.

Thanks for any replies in advance

Martin

Re: Status-Tracking on ACE

UHansen1976 — Tue, 26 Oct 2010 19:54:09 GMT

Hi Martin,

I've never used the CSM platform myself, but I think what you're looking for, is a PROBE.

Basically, a probe is a set of parameters, that can be applied to any of your configured serverfarms and can "track" the status of the underlying real-server, using a variety of protocols, e.g. icmp, tcp, http etc.

Try and have a look at this and see, if it's what you're looking for:

http://www.cisco.com/en/US/docs/interfaces_modules/services_modules/ace/vA2_3_0/command/reference/probe.html

hth

/Ulrich

Re: Status-Tracking on ACE

martin.foote — Wed, 27 Oct 2010 10:20:48 GMT

Hi Ulrich

Thanks for the reply. I'm not sure I was clear on my question, the PROBE would allow me to check the first service is up. What I want to do is make the internal server unavalaible if the external is not PROBING correctly or vice versa. I recognise now this is not identical to status-tracking which operates at a VIP level.

In an example I have two FTP servers which are dual homed with internal and external interfaces in a DMZ both of which are load balanced using the ACE. If the external interface goes down I would want the internal real server to be marked out of service so as FTP traffic is no longer sent there and vice versa if the internal went down I would want to mark the external as down. The configuration in this case is there are different contexts for the internal and external - not saying that's ideal from a security perspective but you can only play with the cards your dealt!.

Thanks

Martin