[plug] OT: Pool of IPs for testing load-balanced connections

Daniel Pittman daniel at rimspace.net
Thu Sep 3 14:16:15 WST 2009

Adrian Woodley <Adrian at Diskworld.com.au> writes:
> Daniel Pittman wrote:
> ...
>>> Friends static ip's. Friends servers hosted somewhere?
>> ...these are good suggestions.  They don't involve abusing a random third
>> party for your own services.
>> [...]
> I should point out at this stage that these facilities are used to support
> the Incident Management Team at Level 2/3 emergencies. Having the Internet
> drop out in the middle of a fire because Adon rebooted his home router
> doesn't sound like an ideal scenario to me.

For a commercial service like this, indeed, it sounds bad to depend on
non-commercial arrangements.  I would expect, in fact, that y'all had some
appropriate contractual arrangement with SLAs to back up whatever you were
rolling out.


> There's not much difference between me throwing the odd icmp at a Telstra
> Boarder (for example) and the same Telstra Boarding having to pass the icmp
> across their network to my (currently non-existent) pool of IPs.

...sure there is: in one case (forwarding ICMP) you have a contractual
arrangement with Telstra to do precisely that.[1]

In the other case, where you bounce ICMP off their equipment, they can quite
legitimately (for example) change the configuration to stop responding without
any concern about what that does to you.

> There's also several orders of magnitude fewer devices in this scenario than
> in the ones listed previously.

Probably.  I don't think that significantly influences things anyhow; I would
be looking at a proper link state or mesh network routing protocol, myself, to
implement these facilities.

Modern protocols and implementations can deliver loop-free, rapidly converging
routing information without reference to external tests, and can even include
link quality information in routing decisions.[2]

Since you ask. ;)


[1]  ...assuming you /do/ have such a contract, which is the case for their
     commercial Internet services, but not necessarily for either their 3G or
     home Internet services.

[2]  Not strictly by the RFC, but there are protocol extensions in real-world
     use that do this for 802.11 mesh networking.

✣ Daniel Pittman            ✉ daniel at rimspace.net            ☎ +61 401 155 707
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