no web-login while internet-connection is down

[andreaspechiny]

Hi,

weve got 2 WLCs (6.0.182.0) and 22 APs in our wireless environment. Last week it was not possible to login to our weblogin. the login page was not reachable.

we identified an error on the internet connection to our provider. only after solving this problem it became possible to login.

i dont untderstand the relation between login on wlc and the internet connection. why doesnt the wlc display the login-page?

i havent found any documentation to this case.

does anybody else know this behaviour?

andreas

[Federico Lovison]

Hi Andreas,

It's hard to say without data, but I would guess this has to do with DNS resolution.

Was the DNS server for your Web-Auth clients reachable during the internet connection outage?

If not, then the may have got the successful redirection only by pointing the browser to an IP address.

DNS resolution is needed in order for the client to send an HTTP request to the desired web server; if DNS resolution fails, then there will be no HTTP request that the WLC can intercept.

I hope this helps.

Thanks,

Federico

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[andreaspechiny]

Hi Federico,

thanks for aour reply.

you ve been right, the DNS server wasnt reachable. but we ve tried to connect directly to the login page via https://1.1.1.1/login.html. Also this page was not reachable.  (1.1.1.1 is the virtual IP.)

why is a DNS server required for this page?

andreas

[Federico Lovison]

Well, no.. DNS is not required for the 1.1.1.1 page, unless you assigned a FQDN name to the virtual interface and you issued a WebAuth certificate based on this FQDN.

In this case you should get redirected to the https:///login.html .. which requires DNS to be operational.

But if you normally get the redirection page to https://1.1.1.1/login.html , then this should have worked... but I would suggest to check with a packet capture on the client itself what happens at that time when the internet connection is down.

Cheers,

Federico