Re: Content switch session incorrect.

kelvin-yeo · ‎04-11-2005

Hi Guys,

i did a test on a set of Load Balancer, which is currently being setup. VIP address is 192.168.11.77 and web server is 192.168.11.48. Port from web server is 8080.

When I telnet to 192.168.11.77 thru port 8080 and try got get a page thru command "GET /nagiosstat/indexright.html", I didn't get the reply.

Noticed that during the transaction, the backend web server (192.168.11.48) come into picture and try to talk to the client (sms). This has caused the transaction between (sms) and 192.168.11.77 become incomplete.

From one server telnet to Web server www.miw.com.sg thru port 8080

sms -> 192.168.11.77 HTTP (proxy) C port=41015

192.168.11.77 -> sms HTTP (proxy) R port=41015

sms -> 192.168.11.77 HTTP (proxy) C port=41015

sms -> 192.168.11.77 HTTP GET /nagiosstat/indexright.html

192.168.11.77 -> sms HTTP (proxy) R port=41015

sms -> 192.168.11.77 HTTP (body)

192.168.11.48 -> sms HTTP (proxy) R port=41015

sms -> 192.168.11.48 HTTP (proxy) C port=41015

sms -> 192.168.11.77 HTTP (body)

192.168.11.48 -> sms HTTP (proxy) R port=41015

sms -> 192.168.11.48 HTTP (proxy) C port=41015

sms -> 192.168.11.77 HTTP (body)

192.168.11.48 -> sms HTTP (proxy) R port=41015

sms -> 192.168.11.48 HTTP (proxy) C port=41015

sms -> 192.168.11.77 HTTP (body)

192.168.11.48 -> sms HTTP (proxy) R port=41015

sms -> 192.168.11.48 HTTP (proxy) C port=41015

Any idea how we can solve this ??

Regards,

kelvin

Gilles Dufour · ‎04-12-2005

Kelvin,

simple.

A loadbalancer is a nating device.

So to work correctly it needs to see traffic from client to server and from server to client.

In your case, it looks like the server can respond directly to the client which will create a problem.

So, put your server in a subnet behing the CSS and make the CSS the default gateway for your server.

Gilles.

kelvin-yeo · ‎04-18-2005

Hi Gilles,

Thanks for the response.

We have another pair of CSS with the same design.

Below is the snoop i got and is working fine.hmmm i'm puzzled.

www.miw.com.sg is support by 1st set of Load Balancer, which is currently in operation. VIP address is 202.79.212.55 and web server is holding another IP address, port from web server is port 80.

When I telnet to www.miw.com.sg (202.79.212.55) thru port 80 and get the page thru command "GET /Home/main.jsp", I get the reply correctly. Noticed that the complete transaction only talk to the vip address - www.miw.com.sg.

From one server telnet to Web server www.miw.com.sg thru port 80

mekong1 -> www.miw.com.sg HTTP C port=54521

www.miw.com.sg -> mekong1 HTTP R port=54521

mekong1 -> www.miw.com.sg HTTP C port=54521

mekong1 -> www.miw.com.sg HTTP GET /Home/main.jsp

www.miw.com.sg -> mekong1 HTTP R port=54521

mekong1 -> www.miw.com.sg HTTP (body)

www.miw.com.sg -> mekong1 HTTP R port=54521

www.miw.com.sg -> mekong1 HTTP (body)

www.miw.com.sg -> mekong1 HTTP inName,features) { //v2.0

www.miw.com.sg -> mekong1 HTTP rc="/Images/blank.gif" width="1" height="5">

mekong1 -> www.miw.com.sg HTTP C port=54521

www.miw.com.sg -> mekong1 HTTP

www.miw.com.sg -> mekong1 HTTP ly:Helvetica; font-size:11px; padding-left:4px;" onfocus="if(value=='Search MIW')

www.miw.com.sg -> mekong1 HTTP obj.style.height = docHeight + 10 + 'px'

mekong1 -> www.miw.com.sg HTTP C port=54521

www.miw.com.sg -> mekong1 HTTP ft">www.miw.com.sg -> mekong1 HTTP a.com/go/getflashplayer" type="application/x-shockwave-flash" width="380" height=

www.miw.com.sg -> mekong1 HTTP height="22" border="0">

mekong1 -> www.miw.com.sg HTTP C port=54521

www.miw.com.sg -> mekong1 HTTP f/NSReg/NSRegister.jsp">www.miw.com.sg -> mekong1 HTTP ttp://www.miw.com.sg/Mindef/ExitPermit/Internet/epAppln.jsp">Apply

www.miw.com.sg -> mekong1 HTTP (body)

mekong1 -> www.miw.com.sg HTTP C port=54521

www.miw.com.sg -> mekong1 HTTP (body)

www.miw.com.sg -> mekong1 HTTP enhancement.asp" target="_blank">

www.miw.com.sg -> mekong1 HTTP

www.miw.com.sg -> mekong1 HTTP idth="100%" border="0" cellspacing="0" cellpadding="7">

www.miw.com.sg -> mekong1 HTTP La

www.miw.com.sg -> mekong1 HTTP ght="25">

mekong1 -> www.miw.com.sg HTTP C port=54521

www.miw.com.sg -> mekong1 HTTP 80" border="0">

www.miw.com.sg -> mekong1 HTTP >Peace of Mind. We've got you covered.

mekong1 -> www.miw.com.sg HTTP C port=54521

I will take your advise and create a new segment behind the CSS.

Gilles Dufour · ‎04-18-2005

if the default gateway of the server is the CSS it will work for clients not in the same subnet as the server.

But it is better to put the servers behind the CSS.

Thanks,

Gilles.

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