Hello Everyone,

If you would like to see other blogs on how to setup IP SLAs check out these links.
IP SLA – Jitter – 1 of 4
IP SLA – ICMP Echo – 2 of 4
IP SLA – TCP Connect – 3 of 4

We’ve arrived at the fourth and final part of this series.  In this blog, we’re talking about the Cisco HTTP IP SLA operation and some ways that it can be useful.

The HTTP IP SLA operation is a very useful tool in the verification of performance of Web servers, Proxy servers, or any other HTTP server.

There are 3 measurements that will provide a total round trip time measurement for the HTTP operation:

• DNS lookup:  How much time it takes to complete a domain name lookup.
• TCP Connect:  How much time it takes to complete a TCP connection to the HTTP server.
• HTTP transaction time:  How long it took to send a request and get a response from the HTTP server.

A good use for this monitor is to confirm that performance stays within the acceptable limits of an SLA and also to gauge your user’s perceptions as to how fast the connection is.
The HTTP IP SLA operation can also be used to monitor proxy servers.  One is example is with a VRRP deployment where there is an HTTP proxy server involved.  If the HTTP IP SLA operation reports a failed connection to the proxy server, a failover process can be initiated automatically so that a secondary router continues to forward all HTTP requests to the proxy server.

The DNS lookup time is an important factor to a good overall user experience.

“How MySpace is hurting your network”, a Networkworld.com article,  explains how social networking sites like MySpace and Facebook  may exponentially increase the number of DNS lookups, impacting the performance of your network.  You may want to check out your netflow analyzer to see whether too many users are checking out these sites.

Cisco IP SLAs can make a huge difference in how well network administrators can increase efficiency of their network.  Pair Cisco IP SLAs with Netflow, good SNMP and Netflow Analyzing applications and you’ll have a winning combination of tools to make sure your network is well tuned.

Thanks for reading this series, good luck and have fun setting up the IP SLAs!

Sincerely,

Chris

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Tags: Cisco, DNS, HTTP, IP SLA, NetFlow, Proxy, SNMP, TCP Connect

This entry was posted on Monday, January 19th, 2009 at 8:38 am and is filed under Denika, General, IP SLA, Network Problem Resolution, Scrutinizer, WebNM. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.