chris.smouse replied on Tue, Oct 13 2009 3:50 PM

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Hi mmunford -

Can you verify that the IPSLA source node (the node running the IPSLA operation) can access the web servers hosting your applications?

Just because your browser can access the web sites doesn't necessarily mean the node actually running the IPSLA operation is able to reach the same web sites.

Hope this helps.

mmunford replied on Tue, Oct 13 2009 4:04 PM

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I have verified that I can telnet (from the SLA router) to port 80 on the target server with similar response as the other HTTP operations targets produce..

chris.smouse replied on Tue, Oct 13 2009 6:10 PM

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The error you're seeing is tied to an error response from the router itself.

Here is a link to Cisco's instructions for debugging the HTTP operation.  You'll want to use the "debug" router commands to determine the cause of the router not being able to execute the HTTP operation.  Is the device low on resources? (memory/CPU)?

http://www.cisco.com/en/US/docs/ios/12_4/ip_sla/configuration/guide/hshttp.html

Hope this helps.

mmunford replied on Wed, Oct 14 2009 4:13 PM

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The Router is definitely not low on CPU/memory resources.. avg of 10%CPU and 25% Mem Util..

cranking up some HTTP debugs now..

I have added a few more operations and a couple more produced the same error. One more HTTP operation and a DHCP operation...

derhally replied on Wed, Oct 14 2009 6:21 PM

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Do you get the same error if you create the http operation manually?

What do you see when you use the "sh ip sla statistics <operation number>" command?

What IOS version are you using?

Chandru replied on Sun, Nov 1 2009 6:39 AM

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Hi Guys,

I have the same issue if i use dns names in the url

http://www.google.com/

But if i use the IP address for the HTTP IP SLA it works fine

Is this a know issue and also when we create a new IP SLA operation it is transferred to the switch the opertaion is created but the config is not saved in the switch (wr mem)

Can you please clarify?

regards

Chandru

chris.smouse replied on Mon, Nov 2 2009 8:54 AM

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Chandru -

Perhaps your IPSLA source node cannot resolve the DNS name?  Can you successfully ping or traceroute the DNS name from the switch itself?

mmunford replied on Mon, Nov 2 2009 11:21 AM

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Hi,

I hadn't had time to dig into the Router Debugs as I had promised earlier.. I just circled back to this this morning after the other thread discussion and have this to report:

In my case, the DNS resolution works fine to the HTTP sites that produce the failure. Changing the operation to use the IP address instead of the FQDN did not make a difference. Here's my new info to add here. It seems if I browse to the URL using a browser and using the FQDN, I can see the site. Browsing using the IP address alone produces an HTTP error message (connection reset in my case). I am assuming from this finding that the IPSLA operation is not passing the URL FQDN as part of the HTTP request. Rather, it seems that perhaps it is resolving the IP via DNS and then constructing a HTTP request using the resolved IP?? I have not done any captures to confirm this yet..

I also did a spot check comparison of the Running and Startup configs on the Router hosting the IPSLA operations and found them to be inconsistent as well..

mmunford replied on Mon, Nov 2 2009 1:04 PM

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I missed your  post Derhally.. sorry bout that..

This router has IOS 12.3 (11) T11 code.. not the newest thing around, definitely. It's using the "RTR" syntax instead of "IP SLA" as well.. 

Perhaps I'll try setting up a few of these operations on a router with newer IOS and post the results..

mmunford replied on Mon, Nov 2 2009 2:52 PM

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The "debug RTR Trace <operation>" produces this output:

.Nov  2 15:48:09.429 est: SAA(40019) Scheduler: Starting an operation
.Nov  2 15:48:09.429 est: SAA(40019) http operation: Starting http operation
.Nov  2 15:48:09.429 est: SAA(40019) dns operation: Starting dns operation
.Nov  2 15:48:09.429 est: SAA(40019) dns operation: Query name - laradirect.cma-cgm.com
.Nov  2 15:48:09.429 est: SAA(40019) dns operation: Query name server - 10.150.8.4
.Nov  2 15:48:09.429 est: SAA(40019) dns operation: Query return code - no error
.Nov  2 15:48:09.429 est: SAA(40019) dns operation: received IP Address 10.0.101.1
.Nov  2 15:48:09.429 est: SAA(40019) dns operation: RTT=1
NOR-VGW-1#
.Nov  2 15:48:09.533 est: SAA(40019) http operation: Sent 18 of 18 bytes
.Nov  2 15:48:09.533 est: SAA(40019) http operation: Wait connection - connected
NOR-VGW-1#
.Nov  2 15:48:11.473 est: SAA(40019) Scheduler: Updating result

Chandru replied on Tue, Nov 3 2009 3:49 AM

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Chris,

Yes i am able to ping and traceroute without any problems

regards

Chandru

mmunford replied on Tue, Nov 3 2009 9:05 AM

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The Target server in question is requiring Host Header requests and is dropping non-conforming connections.

I think perhaps I would need to setup a manual IP SLA HTTP operation and use the HTTP RAW option to specify a HTTP1.1 query that contains the HOST field option.

I haven't verified this yet...

mmunford replied on Tue, Nov 17 2009 1:42 PM

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I tried to manually add a custom IPSLA operation that specified a HTTP RAW request to the target server, but I'm not sure I had the correct syntax.. I'm going to attempt it again soon. 

This logically leads to my next question: If I can manually contruct the appropriate HTTP RAW query, What needs to happen to get ORION to pickup the manual operation for display?? perhaps I missed this in the Docs??

chris.smouse replied on Tue, Nov 17 2009 1:48 PM

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mmunford -

Once you have created the IPSLA operation manually on the router, make a note of the operation number.

Then, go through the Add Operations wizard in IPSLA Manager.  Instead of creating a new operation, you need to choose the "monitor existing" option.

Toward the end of the wizard, you will have the opportunity to enter the operation number for the custom operation.

Hope this helps,

Chris