Re: [squid-users] Round robin DNS with two squid servers and squid_kerb_auth...

>
>Hi All,
>
>We have two squid proxy's running the same config, I want to implement
>a round robin dns solution, so that the browser points to one hostname
>entry, and is being directed to one of the two servers.
>
>Before that i've fully configured the squid proxy server so that it
>works with sqkuid_kerb_auth and squid_kerb_ldap, it works fine, but
>when I enabled round robin dns, I noticed that users weren't being
>authenticated by kerberos, instead it tried to use NTLM, which also
>failed and eventually get a login box (basic).
>
>I'm guessing that the browser parses the dns entry which is configured
>as proxy to squid_kerb_auth, which then tries to use that principal
>name to authenticate? Because its 1 dns entry for two hostnames I
>can't give them both that hostname right?.
>
>Is there another way to configure this?
>
>Relevant Squid Configuration:
>auth_param negotiate program /usr/lib64/squid/squid_kerb_auth -d -s
>host/proxy1.example.com_at_EXAMPLE.COM
>auth_param negotiate children 10
>auth_param negotiate keep_alive on
>
>auth_param ntlm program /usr/bin/ntlm_auth -d 1
>--helper-protocol=squid-2.5-ntlmssp
>auth_param ntlm children 10
>auth_param basic program /usr/bin/ntlm_auth -d 1
>--helper-protocol=squid-2.5-basic
>auth_param basic children 5
>auth_param basic realm Squid proxy-caching web server
>auth_param basic credentialsttl 2 hours
>
>Proxy 2 hase the same config, apart from the -s option for
>squid_kerb_auth which is proxy2.example.com_at_EXAMPLE.COM
>Also even if I don't provide a service principal name, it doesnt work
>(Also with HTTP principals).
>
>When I start a browser whic points to the round robin dns fqdn
>(centralproxy.example.com). and go to which server it's being diverted
>to, I can see this in the logs:
>
>2011/03/23 14:24:53| squid_kerb_auth: DEBUG: Got 'YR
>TlRMTVNTUAABAAAAB4IIogAAAAAAAAAAAAAAAAAAAAAFAs4OAAAADw==' from squid
>(length: 59).
>2011/03/23 14:24:53| squid_kerb_auth: DEBUG: Decode
>'TlRMTVNTUAABAAAAB4IIogAAAAAAAAAAAAAAAAAAAAAFAs4OAAAADw==' (decoded
>length: 40).
>2011/03/23 14:24:53| squid_kerb_auth: WARNING: received type 1 NTLM token
>2011/03/23 14:24:53| authenticateNegotiateHandleReply: Error
>validating user via Negotiate. Error returned 'BH received type 1 NTLM
>token'
>
>If I change the browser to point directly to that proxy server, it
>works like a charm.
>
>Is there a way to fix this? Can round robin dns be used with
>squid_kerb_auth?
>
>Thanks for your time.
>Regards,
>Essad

I believe that this isn't possible due to the DNS/hostname/IP resolution
as you describe. Kerberos is very specific on these requirements when
doing its forward and reverse look-ups/using the SPNs. One option could
be use a PAC/WPAD file and specify your multiple proxies in there..not
really ideal just a thought.
May be possible with some sort of HA/load-balancing, where you can pool
hostnames.

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Received on Wed Mar 23 2011 - 15:43:18 MDT