SSLM Health Probe?

I have a (2) 6509's, each with a CSM and SSLM. One CSM is active and both SSLM's are active. I load balance encrypted requests to the SSLM's.
The SSLM decrypts the incoming HTTPS requests and sends the request back to the CSM using HTTP (clear text). The CSM serverfarm then load balances the session to one of the web servers. Because the web server responds back in clear text, I have implemented a health probe to monitor the web page for a specific string of characters within the serverfarm. If a web page displays the page incorrectly, the probe fails for that server.
Now I have a new requirement, where I must re-encrypt the traffic (backend encryption) and send the requests to the server encrypted (HTTPS).
My question are:
1. Can I implement health probes on the SSLM?
2. Can I implement an effective health probe from the CSM so that I can still poll for a string of characters?
Thank you.

SSLM should only be probed with ICMP

Similar Messages

ACE http health probes - best practice for interval and passdetect interval?

Hi,
Is there a recommended standard for http health probes in terms of interval and passdetect interval timings, i.e. should the passdetect interval always be less than the interval or visa versa? Can a http probe be 'mis-configured', i.e. return a 'false positive' by configuring an interval timeout thats 'incompatible' with the device it's polling?
I have a http probe for a serverfarm consisting of two Apache http servers and get intermittent 'server reply timeout' probe failures. I'm keen to ensure that the configuration of the probe isn't at fault so I can be confident that a failed probe indicates a problem with the server and not my configuration.
The probe is currently configured as below:-
probe http http-apache
interval 30
passdetect interval 15
passdetect count 6
request method get url /cs/images/ACE.html
expect status 200 304
Any advice on the subject woud be gratefully received.
thanks
Matthew

Hi Gilles,
Thanks for the advice. In another dicussion (found here https://supportforums.cisco.com/message/462397#462397) a poster has stated that:-
"(The) "Probe interval" should always be less then (open+recieve) timeout value. Default open & receive timeouts are 10 seconds."
Are you able to advise on whether the above is correct and if so, why? I currently have an interval value of 30 that obviously goes against the advice above (which I've interpretted to mean that if you leave the open & receive timeouts at their default settings your probe interval should be less than 20 seconds?).
thanks
Matthew

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probe tcp TCP-25
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CSM 4.2(5): Reoccuring failed health probes

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I've finally started to investigate an issue I have with our CSM setup. Several times a day I get the below syslog message from the 6500
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Those error messages are related to probing the CSM does when determining server health. For a TCP probe, this means that the CSM either gets a TCP RST from the server or it does not see a SYN-ACK coming from the server.

Configuring Health Probe for Server Farm

If I have a server farm with real servers listening on port 8888 and I apply an HTTP-type health probe with no port number specified, will the ACE know to probe the servers at 8888 or will it try to probe port 80?

Hi,
Yes it should inherit the port from the real servers defined in the serverfarm. This gives you the flexibility to associate same probe with different serverfarms probing different servers on different ports. This is probe port inheritance feature which is there in ACE.
Regards,
Kanwal

CSM health probe for server farm with multiple vservers

Is there a way to specify the vserver port that a health probe monitors when multiple vservers are configured for the same serverfarm? Let's say I have a serverfarm named farm1. farm1 services two ports www and https so two vservers vserver_www and vserver_https are configured and bound to farm1. I would like to enable http health probe on farm1 with the intention of only monitoring vserver_www http port but, instead, the health probe monitors both www and https and since a http probe on https fails it takes farm1 reals and both vservers vserver_www and vserver_https out-of-service. Is there a way to configure a health probe to monitor a specific port? Or, should I create two duplicate serverfarms farm1 bound to vserver_www and farm2 bound to vserver_https and only enable http health probe on farm1? Any other ideas welcomed.

Appreciate the feedback. I also found what I was looking for in configuration examples. To summarize I've borrowed the comment from the URL below:
# The port for the probe is inherited from the vservers.
# The port is necessary in this case, since the same farm
# is serving a vserver on port 80 and one on port 23.
# If the "port 80" parameter is removed, the HTTP probe
# will be sent out on both ports 80 and 23, thus failing
# on port 23 which does not serve HTTP requests.
http://www.cisco.com/univercd/cc/td/doc/product/lan/cat6000/mod_icn/csm/csm_4_2/config/cfgxpls.htm

Health probe for RDP farm

I have an RDP server farm that lost a disk. The RDP service was still running but users were unable to log in. I'd like to create a health probe that does maybe a combination of TCP probe for port 3389 and something that can determine if the drive that stores user profiles is available.
I cannot add any new service (http or ftp) to the server.
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Thanks.

Can you drop me a mail offline ([email protected]) and I can share what I have. Matthew

ACE Health probe using get URL

Hello,
We are trying to create a health probe for our google search appliances and as part of the URL get there is a question mark but the ACE doesn't like that. Is there a way around this or should it be done differently?
request method get url /searchq? (This is what we want the URL to be)
request method get url /searchq (This is where it thinks i'm asking it for help)
Thanks in Advance.

Hello,
You need to typ CRTL+v prior to entering the ?
That's the Control key then lowercase v, then your question mark.
Hope this helps,
Sean

CSM HTTP Health Probe

Is there any way to configure an HTTP health probe that will test a web page and fail if it takes too long for the server to respond. I have attempted to do this (see below) but the "receive" parameter doesn't seem to help. We are currently having a problem where one of the web servers for whatever reason gets really slow, while the other works fine with about the same number of users, I'd like to fail the slow when this occurrs.
Here is my probe config:
probe HTTP-SERVERASP http
request method get url /server.asp
expect status 200 299
interval 5
failed 30
receive 5
Thanks...Jeff

Jeff,
receive seems to be the solution for what you need.
Did you verify how fast/slow the server is responding.
Currently you allow 5 sec for the response to come back and 3 consecutives must fail before the server is brought down, so if your server resond 1 time fast enough, the server stays up.
So, use a sniffer trace to verify the response time.
Send me the trace if you want.
Gilles.

Cisco ACE Health Probes

Probe Interval: 5
Pass Detect (Seconds): 60
Fail Detect: 3
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Also if we have a primary server and a back up server (used if primary fails), if the primary fails and the backup server becomes active, will the primary server become available again when it comes back online, or will all connections continue to go to the backup? Is there anyway to make the old primary the new backup when it comes back online?

Hi,
You are right about Probe interval and fail detect, but Pass detect has two parameters:-interval and count, where interval defines the amount of time to wait for sending the probe back to failed server where as count paramater will control the minimum succefullt probe return from server for making it active again.
Regarding the backup server, once the prmary server comes online again all new connection will be redirected to it, while all existing connection will continue on existing one. I guess "inservice standby" will be the command of your interest in gracefully removing the primary and bringing the backup active.

CSM Health Probe source IP

Can anyone tell me what IP address health probes are sourced from on the CSM? I've got a simple ICMP health probe setup but I'm trying to figure out what the source of those probes will be.
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Bob

this is the vlan ip.
Gilles.

Multiple health probes on CSM

We have a CSM blade in a 6509, IOS 12.2(18)SXF7, CSM softvare version 4.2(7);
We'd like to create a serverfarm, where servers are checked for several ports and only considered as working when all probes succeed.
Although Cisco docs state that there should be a possibility to associate multiple probes with a serverfarm, I haven't managed to do so.
Here's what I've tried:
probe PING icmp
interval 5
failed 10
receive 4
probe TCP-1234 tcp
interval 10
retries 2
failed 25
port 1234
real PROBE-TEST-R
address 1.2.3.4
serverfarm PROBE-TEST-SF
real name PROBE-TEST-R
health probe PING
health probe TCP-1234
but when trying to add the second probe, I get:
% You must first disassociate from probe PING.
Any ideas, how multiple probes could be implemented?

Configure them as probe under the serverfarm..not health probe.
serverfarm PROBE-TEST-SF
probe PING
probe TCP-1234
Gilles.

CSM HTTPS or SSL Health Probe

We are currently using TCP probe for HTTPS webServer health checking. Is there a HTTPS or SSL probe available on CSM to send a url to detect if the HTTPS Apache WebServer is up or not?
Many Thx, Q.Xie

You can download the TCL script file from the same locstion as the CSM software.
In this TCL file you should find the following scripts
[root@linux-1 cisco]# cat /tftpboot/c6slb-apc.4-2-1.tcl | grep -i "name ="
#!name = CHECKPORT_STD_SCRIPT
#!name = ECHO_PROBE_SCRIPT
#!name = FINGER_PROBE_SCRIPT
#!name = FTP_PROBE_SCRIPT
#!name = HTTPCONTENT_PROBE
#!name = HTTPHEADER_PROBE
#!name = HTTPPROXY_PROBE
#!name = HTTP_PROBE_SCRIPT
#!name = IMAP_PROBE
#!name = LDAP_PROBE
#!name = MAIL_PROBE
#!name = POP3_PROBE
#!name = PROBENOTICE_PROBE
#!name = RTSP_PROBE
#!name = SSL_PROBE_SCRIPT
#!name = TFTP_PROBE
There is a SSL_PROBE_SCRIPT that will verify that the SSL server respond to a client SSL HELLO message.
It does not verify if you can send an HTTP request.
It only sends a HELLO as a client and wait for the server HELLO.
With the SSLM for the CSM, there might be a way to achieve HTTPS probe.
I never tried it, but the solution I see would be to create an HTTP probe on the CSM and direct to the SSLM which will do the encryption and forward it to the server.
Regards,
Gilles

Issue with regexes in http health probes on ACE 4710

Folks,
We're currently experiencing fairly bizarre behavior when attempting to set up http probes that expect a regexp. Namely, if we specify a regexp, the probe *always* passes, regardless of status code and regardless of whether or not the message actually matches the pattern. Doing 'no expect regexp' fixes this behavior (by which I mean that the 'expect status' rules work again).
We haven't noticed until now because this is the first time we've tried to set up a probe that does this. Are we missing something? Is this a known issue with our current firmware version?
Sincerely,
Patrick T. Ramsey
# show run probe | begin HTTP-nfscheck | end regex
Generating configuration....
probe http HTTP-nfscheck
description Simple HTTP probe to check nfs mount health
port 80
interval 15
passdetect interval 20
request method head url /nfs-health-check/
open 1
expect regex "^ureytgraeuikghfdjg$"
# sh ver
Cisco Application Control Software (ACSW)
TAC support: http://www.cisco.com/tac
Copyright (c) 1985-2009 by Cisco Systems, Inc. All rights reserved.
The copyrights to certain works contained herein are owned by
other third parties and are used and distributed under license.
Some parts of this software are covered under the GNU Public
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http://www.gnu.org/licenses/gpl.html.
Software
loader:    Version 0.95.1
system:    Version A3(2.4) [build 3.0(0)A3(2.4) adbuild_11:46:02-2009/09/27_/auto/adbu-rel2/rel_a3_2_3_throttle/REL_3_0_0_A3_2
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system image file: (hd0,1)/c4710ace-mz.A3_2_4.bin
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I also went through a similar issue in which we need to probe the real server PESERVER01 and if the real server replies with the keyword "PE Server" in the HTTP content then the probe should be passed successful.
In my case the real server was listening on port 32776 for HTTP service so we configured the serverfarm as below,
serverfarm host SF-TEST-32776
description SF-TEST-32776
failaction purge
probe PE-SERVER-STRING
rserver PESERVER01 32776
    inservice
And the TCP probe as below,
probe tcp PE-SERVER-STRING
port 32776
send-data GET /IOR/ping HTTP/1.1      <<== command should not be in inverted commas
expect regex "PE Server"
The above probe worked really well and when we checked the probe status it was marking as success. I also tried changing the regex from "PE Server" to "Vishal12345" and it was failing as expected because there was no such keyword in the HTTP content.
==================================================================================
T2-LB02# sh probe PE-SERVER-STRING
probe       : PE-SERVER-STRING
type        : TCP
state       : ACTIVE
   port      : 32776   address     : 0.0.0.0         addr type : -
   interval : 15      pass intvl : 60              pass count : 3
   fail count: 3       recv timeout: 10
                ------------------ probe results ------------------
   associations ip-address      port porttype probes   failed   passed   health
   ------------ ---------------+-----+--------+--------+--------+--------+------
   serverfarm : SF-TEST-32776
     real      : PESERVER01[32776]
                10.10.10.1    32776 PROBE    105      0        105      SUCCESS
==================================================================================
I was struggling with this issue from long time. Even raised couple of Cisco TAC cases with no luck. The most important thing here is to identify the exact command to be send to real server like GET /IOR/ping HTTP/1.1 that we used here.
To collect this command I did packet capture on one of the client machine and then tried to open the URL from real server which can return the string "PE Server". Then analyzed the captures in Wireshark and checked the HTTP data with follow the TCP stream option in which I seen the below data, which gives the command to be send in probe as well as the string we should expect.
==================================================================================
GET /IOR/ping HTTP/1.1
User-Agent: curl/7.19.7 (x86_64-redhat-linux-gnu) libcurl/7.19.7 NSS/3.12.9.0 zlib/1.2.3 libidn/1.18 libssh2/1.2.2
Host: 10.144.70.85:32776
Accept: */*
HTTP/1.0 200 OK
Content-type: text/html
Ping
PE Server
WRVFKO11 [Win32 Server Production (3 silos) (Oracle Blob 512 MB) -- {dap451.007.028 dap451.004.002 pe451.003.010x pui451.003.010 pui451.001.004} Mar 9 2012 15:07:53 en ]
===================================================================================
Please try this and see if it helps you.
Thanks,
Vishal Babrekar

ACE Health probe for SIP

I've setup a SIP probe to check the health of a Microsoft OCS. The health of this server is always failed. What am I missing? I also tried it with a telnet probe on port 5061, but got the same result. A telnet from ACE to the server on port 5061 works fine.
See below a show probe SIP detail and the relevant configuration.
ACE21_Secondary/MOCS# sh probe SIP det
probe : SIP
type : SIP
state : ACTIVE
description :
port : 5061 address : 0.0.0.0 addr type : -
interval : 10 pass intvl : 10 pass count : 3
fail count: 3 recv timeout: 4
request-method : OPTIONS
conn termination : GRACEFUL
expect offset : 0 , open timeout : 2
expect regex : -
------------------ probe results ------------------
associations ip-address port porttype probes failed passed health
------------ ---------------+-----+--------+--------+--------+--------+------
rserver : OCS_11
10.105.11.70 5061 -- 7566 7566 0 FAILED
Socket state : CLOSED
No. Passed states : 0 No. Failed states : 0
No. Probes skipped : 0 Last status code : 0
No. Out of Sockets : 0 No. Internal error: 0
Last disconnect err : Server reply timeout (no reply)
Last probe time : Thu Oct 30 14:18:42 2008
Last fail time : Tue Oct 28 16:31:30 2008
Last active time : Never
ACE21_Secondary/MOCS# sh run
probe sip tcp SIP
port 5061
interval 10
passdetect interval 10
receive 4
expect status 200 200
open 2
rserver host OCS_11
ip address 10.105.11.70
probe SSL
probe PING
probe SIP
probe SIP_TELNET
inservice
Cheers
Peter

Peter,
make sure to NOT run version A2(1.1a) as SIP probes are broken in that specific release.
If your version is something else, get a sniffer trace on the server to see what is going on.
Seems like we don't get a reply according to the line :
"Last disconnect err : Server reply timeout (no reply) "
Gilles.

SSLM Health Probe?

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