Quick question from a routing noob: I've just acquired 210.48.96.88/30. The two IP addresses in the block are intended for a couple of vmware instances. We're not using anything nice like a Cisco router, just a Linksys stand-in for now. It has some basic static routing capabilities. I had a short conversation with Iconz support but I'm not feeling very confident about the result. I've been instructed (or rather I said "this is what we came up with" and I got a vague "yes") to add the following entry to the routing table (where 202.37.231.84 is the existing IP that we're using as an external address): Destination: 210.48.96.88 Subnet: 255.255.255.252 Gateway: 202.37.231.84 Interface: Local It's the gateway bit we're unsure of - won't this cause a loop? My mate is concerned that it's not going to work as it needs to be on the same subnet. Cheers Justin
Justin Cook wrote:
Quick question from a routing noob:
I've just acquired 210.48.96.88/30. The two IP addresses in the block are intended for a couple of vmware instances. We're not using anything nice like a Cisco router, just a Linksys stand-in for now. It has some basic static routing capabilities.
I had a short conversation with Iconz support but I'm not feeling very confident about the result. I've been instructed (or rather I said "this is what we came up with" and I got a vague "yes") to add the following entry to the routing table (where 202.37.231.84 is the existing IP that we're using as an external address):
Destination: 210.48.96.88 Subnet: 255.255.255.252 Gateway: 202.37.231.84 Interface: Local
Really, ICONZ are the only ones that can answer this, however, if the network in question were a point to point link then what you describe (allocating a /30, or even two disparate random ips) would work due to it essentially being interface routed, but a broadcast network (which most hosts seem to expect when plugged in via ethernet - even simulated) really needs a gateway on the same network or strangeness [tm] tends to happen, I would have assumed that if you already had a /30 from ICONZ for your existing infrastructure that they would just widen this to a /29 for you as it doesn't make for any more or less address space wastage and allows you to do what you want easily. -- Steve.
On Sun, 21 May 2006, Justin Cook wrote:
I've just acquired 210.48.96.88/30. The two IP addresses in the block are intended for a couple of vmware instances. We're not using anything nice like a Cisco router, just a Linksys stand-in for now. It has some basic static routing capabilities.
Heya Justin. I saw your mail to NZNOG - I hope this will help. Your new subnet has been routed out to the static IP of your router, which will be assigned to the _external_ interface. What you'll want to do is assign an IP from the new subnet to the _internal_ interface on your linksys - this ip will then be your gateway IP for all of your servers (or VMware instances). Those servers (or VMWare instances) should be assigned IPs from the rest of the new subnet. Please note that a /30 only gives you two usable IP addresses, that's no good because you'll be using one of them for your internal interface on the router, and you want to then run a couple of servers as well. I've just checked, and that /30 can be expanded into a /29 easily. So easily, in fact, that we've just pre-emptively changed to a /29 for you. :) That gives you six usable IP addresses in your new /29 subnet. Attached is a diagram which shows you how you should set things up at your end - any questions, feel free to contact me. JSR
participants (3)
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John S Russell -
Justin Cook -
Steve Phillips