[cisco-bba] Oddities with L4 time redirects

Andy Saykao andy.saykao at staff.netspace.net.au
Wed Sep 30 22:11:15 EDT 2009

Hi All,

Is anyone using L4 time redirects in production? 

I'm testing this feature at the moment by using radius flat files to
assign them to me when I log on but I'm seeing weird results from my

redirect-dbtemp          Password = "xxxxxxx"
        Service-Type = Framed-User,
        Framed-Protocol = PPP,
        Framed-Address = 203.17.103.x,
        Framed-Netmask =,
        cisco-avpair = "ip:l4redirect=redirect to ip 210.15.254.x 80
duration 10 frequency 120",

#1 Oddity: Browser hangs at the start.

Sometimes when I log on for the very first time my browsing will just
hang. For example my home page is Google and when I first connect and
open up my browser, it will hang without loading Google before timing
out. I'll then press refresh and Google will load.

#2 Oddity: Browser caches redirect web page.

When the redirect actually happens and takes my browser to 210.15.254.x
80, the redirect page remains cached even after doing a refresh. For
example, if my browser is currently on www.google.com and the redirect
kicks in, I'll be taken to the redirect page. My browser still shows the
URL www.google.com in the browser tool bar when the redirect page loads.
I will then refresh the page and google will not load. I have to
actually do a force refresh for google to load. I have been able to
resolve this by not caching the page with the "<META HTTP-EQUIV="PRAGMA"

#3 Oddity: Browser hangs intermittently

On some occassions when the redirect kicks in, the same thing as #1 will
happen. The browser will just hang there as it tries to redirect before
getting a page time out. For example I'll just be continually hitting
the refresh button while my browser is at www.google.com and then when
the redirect kicks in, the page just hangs before timing out.

#4 Oddity: Redirect page can not be found

For example, I'll be searching for a search term in Google so the URL of
the page looks like this
a=&fp=c5fbc323c9147fb8". I'll keep hitting refresh while the URL remains
like that. When the redirect kicks in, I am redirected to 210.15.254.x
80 but instead of the index.html page being displayed I get a page not
found from the web server where the redirect page is hosted. Seems like
the redirect is appending all those weird characters in the URL to the
redirected IP resulting in a page not found. To get around this I've had
to edit Apaches 404 error page to return the same content as the
index.html page.

Although L4 time redirects have been around for a bit, I'm surprised
it's still very buggy (atleast according to my testing).

LNS = Cisco 7301 (Version 12.2(31)SB14)



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