nanog mailing list archives
Re: Is multihoming hard? [was: DNS amplification]
From: Jimmy Hess <mysidia () gmail com>
Date: Sat, 23 Mar 2013 14:12:48 -0500
On 3/23/13, Owen DeLong <owen () delong com> wrote:
A reliable cost-effective means for FTL signaling is a hard problem without a known solution.
Faster than light signalling is not merely a hard problem. Special relativity doesn't provide that information may travel faster than the maximum speed C. If you want to signal faster than light, then slow down the light.
An idiot-proof simple BGP configuration is a well known solution. Automating it would be relatively simple if there were the will to do so.
Logistical problems... if it's a multihomed connection, which of the two or three providers manages it, and gets to blame the other provider(s) when anything goes wrong: or are you gonna rely on the customer to manage it? Someone might be able to make a protocol that lets this happen, which would need to detect on a per-route basis any performance/connectivity issues, but I would say it's not any known implementation of BGP.
1. ISPs are actually motivated to prevent customer mobility, not enable it.
2. ISPs are motivated to reduce, not increase the number of multi-homed sites occupying slots in routing tables.
This is not some insignificant thing. The ISPs have to maintain routing tables as well; ultimately the ISP's customers are in bad shape, if too many slots are consumed. How about 3. Increased troubleshooting complexity when there are potential issues or complaints. The concept of a "fool proof" BGP configuration is clearly a new sort of myth. The idea that the protocol on its own, with a very basic config, does not ever require any additional attention, to achieve expected results; where expected results include isolation from any faults with the path from one of of the user's two, three, or four providers, and balancing for optimal throughput and best latency/loss to every destination. BGP multihoming doesn't prevent users from having issues because: o Connectivity issues that are a responsibility of one of their provider's That they might have expected multihoming to protect them against (latency, packet loss). o very Poor performance of one of their links; or poor performance of one of their links to their favorite destination o Asymmetric paths; which means that when latency or loss is poor, the customer doesn't necessarily know which provider to blame, or if both are at fault, and the providers can spend a lot of time blaming each other. These are all solvable problems, but at cost, and therefore not for massmarket lowest cost ISP service. It's not as if they can have "Hello, DSL technical support... did you try shutting off your other peers and retesting'?" The average end user won't have a clue -- they will need one of the providers, or someone else to be managing that for them, and understand how each provider is connected. I don't see large ISPs training up their support reps for DSL $60/month services, to handle BGP troubleshooting, and multihoming management/repair.
In addition, most of the consumers that could benefit from such a solution do not have enough knowledge to know what they should be demanding from their vendors, so they don't demand it.
Owen
-- -JH
Current thread:
- Is multihoming hard? [was: DNS amplification], (continued)
- Is multihoming hard? [was: DNS amplification] Patrick W. Gilmore (Mar 20)
- Re: Is multihoming hard? [was: DNS amplification] Owen DeLong (Mar 20)
- Re: Is multihoming hard? [was: DNS amplification] ML (Mar 20)
- Re: Is multihoming hard? [was: DNS amplification] Seth Mattinen (Mar 20)
- Re: Is multihoming hard? [was: DNS amplification] Joe Abley (Mar 20)
- Re: Is multihoming hard? [was: DNS amplification] Jared Mauch (Mar 20)
- Re: Is multihoming hard? [was: DNS amplification] Masataka Ohta (Mar 20)
- Re: Is multihoming hard? [was: DNS amplification] Owen DeLong (Mar 20)
- Re: Is multihoming hard? [was: DNS amplification] Valdis . Kletnieks (Mar 22)
- Re: Is multihoming hard? [was: DNS amplification] Owen DeLong (Mar 23)
- Re: Is multihoming hard? [was: DNS amplification] Jimmy Hess (Mar 23)
- Re: Is multihoming hard? [was: DNS amplification] Owen DeLong (Mar 23)
- Re: Is multihoming hard? [was: DNS amplification] Kyle Creyts (Mar 23)
- Re: Is multihoming hard? [was: DNS amplification] Matt Palmer (Mar 23)
- Re: Is multihoming hard? [was: DNS amplification] joel jaeggli (Mar 24)
- Re: Is multihoming hard? [was: DNS amplification] William Herrin (Mar 24)
- Re: Is multihoming hard? [was: DNS amplification] John Curran (Mar 24)
- Re: Is multihoming hard? [was: DNS amplification] Leo Bicknell (Mar 25)
- Re: Is multihoming hard? [was: DNS amplification] Kyle Creyts (Mar 24)
- Re: Is multihoming hard? [was: DNS amplification] George Herbert (Mar 24)
- Re: Is multihoming hard? [was: DNS amplification] Owen DeLong (Mar 24)