All,

I'm lost.  Things have... changed since I last used LVS back in '02/'03.
Like someone has re-arranged the furniture and I can't quite figure
out what has moved.

I've spent several of days reading through the HOW-TO, the mini-HOW-TO, 
and the configure script perldocs and I can't, for the life of me, 
figure out a) why my LVS-DR *is* working and b) why I can't connect to 
127.0.0.1 on the real servers without specifically allowing connections 
to lo in iptables.

On the director, the VIP is up and running.  On the real servers, it
isn't - not on eth0, nor on lo - and yet I _can_ connect from a client 
to the VIP and I get directed to a real server.  Watching tcpdump on the 
director and the real server I see the packets get redirected on the LVS 
to the real server and the real server back to the client.

So, here's where it gets weird: if I disable the transparent proxy on 
the real servers, I can't connect.  Joe says this shouldn't work, yet it is.

I've also configured arptables according to the HOW-TO, but since the TP 
is in place, it's probably hard to tell if they are working correctly.

So, the questions I have are these:

Why don't I need to bring up the VIP on the real servers? Is this 
normal?  Is this expected?

And why can't I connect to 127.0.0.1 on the real server without 
specifically allowing connections with iptables?

I put the lvs.cf, director and real server iptables, and real server 
arptables in the following directory for people to peruse and comment on:

http://home.fnal.gov/~yocum/lvs-dr-Oct07/

Thanks in advance,
Dan


Dan Yocum wrote:
> 
> lists wrote:
>> Joseph Mack NA3T wrote:
>>>> # horm's tranparent proxy for LVS
>>>>     
>>> doesn't work anymore.
>>>   
>> iptables REDIRECT (horm's method) still works on the real servers (not 
>> sure it ever did on the LVS host.)
>> It has more latency than the modern 2.6 sysctl way though.
> 
> Oh, interesting.  arp_announce and arp_ignore.  Thanks for the hint. 
> Ah, but those are only for physical interfaces and will even affect 
> so-called virtual interfaces (i.e., eth0:0).
> 
> How much more latency are you talking about?  Using horm's method I was 
> able to transfer 9.8Gbps through a whole bunch of gridftp servers back 
> in '05 and the traffic on the director only increased 100-200kbps. 
> Granted, latency != throughput, all the time.
> 
> Ah, yes, now I'm starting to remember why horm's wrote the transparent 
> proxy stuff: arptables still wasn't available in RH kernels.  Now that 
> it is, I may look at.  But, I'm rather happy to keep my transparent 
> proxy stuff in iptables from days of yore, if it works.
> 
> Thanks,
> Dan
> 
> 

-- 
Dan Yocum
Fermilab  630.840.6509
[EMAIL PROTECTED], http://fermigrid.fnal.gov
Fermilab.  Just zeros and ones.


_______________________________________________
LinuxVirtualServer.org mailing list - [email protected]
Send requests to [EMAIL PROTECTED]
or go to http://lists.graemef.net/mailman/listinfo/lvs-users

Reply via email to