[BlueOnyx:14028] Re: Problem setting interface alias netmask to 255.255.255.255

[Chuck Tetlow]

Chris,

I suspect his server is set up the same way as a number of servers I manage. 

There is a route-able IP on the main server interface, and all the virtuals are on IPs in a different network.  So the 255.255.255.255 netmask is valid for the virtuals.  The server knows to send all traffic to its default gateway router.  And the router has to be told to send traffic destined for the virtual IPs to the main server IP.

This is what happens when you have the main IP for the server in a different network as the virtual site IPs.

There is a possibility that his main server IP and the virtuals are in the same /24 network, just not consecutive.  In that case, the 255.255.255.0 netmask is valid - and his ISP is simply trying to cut down on the amount of broadcast traffic.  And if that's the case - I agree with your opinion - tough shit!  They created the problem, they should fix it.

Chuck

---------- Original Message -----------
From: Chris Gebhardt - VIRTBIZ Internet <cobaltfacts at virtbiz.com> 
To: blueonyx at mail.blueonyx.it 
Sent: Wed, 13 Nov 2013 06:24:41 -0600 
Subject: [BlueOnyx:14011] Re: Problem setting interface alias netmask to 255.255.255.255

> On 11/13/2013 5:47 AM, Menno Jansz wrote: 
> > 
> > 
> > Well they are saying that if I change the alias ips to have netmask 
> > 255.255.255.255 then the problem is resolved. But Blueonyx GUI wont let me 
> > set that. 
> > 
> > To be honest I have never got my head round the netmask stuff, but they 
> > say they force all their other clients to do this otherwise their routers 
> > get flooded with unnecessary arp who-has requests. 
> 
> Hi Menno, 
> I may bring a bit of a different perspective to the table here, which is 
> that of a service provider.   In that case, regarding the request to set 
> your netmask to 255.255.255.255, I say "what the what?!?!" 
> 
> That ranks right up there as one of the strangest things I have heard. 
> 255.255.255.255 is not a proper netmask for a routeable IP address, and 
> their request just does not make sense.   They're within their rights to 
> ask you not to use a /24 netmask (255.255.255.0), but then again, if 
> they have you properly subnetted, that would never be a problem for them 
> (although it could cause issues on your end). 
> 
> I would advise you to reply back to them to provide you the ACTUAL 
> netmask to use for the IP's provided, or don't bother with blocking the 
> IP's, you'll take your business to a provider who will get you actual IP 
> assignments. 
> 
> The IP addresses they gave you are clearly in a subnet of some type. 
> Their refusal to tell you what that subnet is baffles me.   If I had to 
> guess, I'd say that they are simply handing you IP addresses out of an 
> allocation without concern as to subnetting.  That screams "amateur" to 
> me.  The heavy-handed response about blocking your access because they 
> have failed to instruct you on a proper netmask has, as you may be able 
> to tell, set my teeth on edge. 
> 
> -- 
> Chris Gebhardt 
> VIRTBIZ Internet Services 
> Access, Web Hosting, Colocation, Dedicated 
> www.virtbiz.com | toll-free (866) 4 VIRTBIZ 
> _______________________________________________ 
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> Blueonyx at mail.blueonyx.it 
> http://mail.blueonyx.it/mailman/listinfo/blueonyx 
------- End of Original Message -------
 
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