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"BGP at home": getting a DIA circuit installed at home

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Re: "BGP at home": getting a DIA circuit installed at home

#81

Post by remram »

dboreham wrote: post #20
remram wrote: post #11

Earlier quoted context omitted.

It sounds like they wanted 2 separate network paths but they still end up with only 1 where they can use BGP. Maybe they can still use their residential connection as failover, with a VPN to a VPS where they can use BGP?

They all likey traverse the same physical path and would all be taken out by the same gravel truck hitting a pole. The two connection thing was I think more about defense against random retail connectivity flaps (someone decides to upgrade a router's firmware and just takes the town offline, meanwhile nobody answers support calls, that sort of thing).

True. I thought they wanted BGP to implement multihoming but upon re-reading they needed it anyway for other reasons.

Re: "BGP at home": getting a DIA circuit installed at home

#82

Post by dboreham »

remram wrote: post #81
dboreham wrote: post #20

Earlier quoted context omitted.

They all likey traverse the same physical path and would all be taken out by the same gravel truck hitting a pole. The two connection thing was I think more about defense against random retail connectivity flaps (someone decides to upgrade a router's firmware and just takes the town offline, meanwhile nobody answers support calls, that sort of thing).

True. I thought they wanted BGP to implement multihoming but upon re-reading they needed it anyway for other reasons.

BGP would be to allow fail over of some service from their primary colo.

Re: "BGP at home": getting a DIA circuit installed at home

#83

Post by tiernano »

techsupporter wrote: post #45
markonen wrote: post #41

I rent a single ~600 meter fiber that connects my home to the network infrastructure of the company I run. The rent is $75/mo or so. I have passive CWDM muxes on the line to run two 10G connections to two separate edge routers. My home router is a MikroTik CRS309—it’s about $250, fanless, has 8 SFP+ ports and advertises my home network blocks over BGP to the two routers (for HA). The setup works great. The best part…

> My home router is a MikroTik CRS309 ... advertises my home network blocks over BGP How do you fit two full BGP tables into 512MB of RAM? I've looked into MikroTik boxes before and maybe they're doing something I'm not understanding. On the routers I have manage, two IPv4 feeds take up about 1.1GB and three IPv6 adds another 450MB.

I have their RB5009 with 1Gb RAM and I got 4 full feeds and have around 200Mb free. I do need to tweak stuff to get IPv6 working (again... only been sorting this out in the last couple weeks)

Re: "BGP at home": getting a DIA circuit installed at home

#84

Post by icedchai »

Habgdnv wrote: post #64

I've been running BGP at home for the last 10 years, and in my area, most ISPs prefer to use Dedicated Internet Access (DIA) for BGP sessions. Fortunately, I live in a place where there are a few smaller ISPs with around 2000-3000 customers that are willing to run BGP with me as a home user. They're impressed that I have BGP, ASN, and IPs as a home user, and I think it's pretty cool too. Additionally, running one mor…

You're lucky. There are basically no small ISPs around here anymore. It's the cable company (DOCSIS) or telco (fiber, or DSL if you're unlucky.) Without paying for an enterprise grade connection, it would be impossible to get a BGP session through either.

I also have a /24 for myself. I've had it since the mid-90's, from the InterNIC days, predating ARIN. I've gone years without using any of the addresses. Currently it's routed to my home lab. I'm doing BGP through a couple VPSes, then tunneling it back.

Re: "BGP at home": getting a DIA circuit installed at home

#85

Post by bogomipz »

Habgdnv wrote: post #64

I've been running BGP at home for the last 10 years, and in my area, most ISPs prefer to use Dedicated Internet Access (DIA) for BGP sessions. Fortunately, I live in a place where there are a few smaller ISPs with around 2000-3000 customers that are willing to run BGP with me as a home user. They're impressed that I have BGP, ASN, and IPs as a home user, and I think it's pretty cool too. Additionally, running one mor…

There seems to be a lot of misconceptions in your post.

>"Additionally, running one more BGP session makes their network appear larger, so they benefit as well."

This doesn't make any sense. The number of "BPG sessions" is not a metric any ISP thinks about. A BPG session is just TCP connection. The number of prefixes an ISP is advertising might be something they care about however but for smaller ISPs that doesn't really matter as they are just customers of the Tier 1 ISPs and that just requires paying the Tier 1 ISP. It has nothing to do with the number of sessions or prefixes. I could have a single /22 prefix for my company and the Tier 1 ISP will still sell me the same service.

>"There's no rule that says ISPs should only accept /24 or shorter prefixes, and this is contributing to the depletion of IPv4 addresses. I would happily announce a /25 and return the other /25 to the world, but I must have a /24 to do it."

Well yes there is. Many ISPs will generally not accept routes smaller than a /24. They configure filter-lists that prevent those routes from being accepted. The reason for this is to reduce the size of the global routing table. Each prefix has to be stored in TCAM(memory) on a router. There have been many incidents where older routers couldn't handle the number of routes in the global routing table and caused them outages. See:

https://arstechnica.com/information-technology/2014/08/inter... and https://www.inap.com/blog/growing-pains-internet-global-rout...

Further if you have a /24 you can certainly advertise 2 /25s to the same upstream ISP if you have more than one transit connection with them. In fact this is exactly how do traffic engineering.

>"It's frustrating that some ISPs make it artificially difficult for home users to obtain a BGP session, even when they're not asking for SLAs or dedicated connections."

This because home users absolutely don't need to run BGP! You just take a default route from your ISP and you're done with it. There is not point in running BGP if you are single-homed! You can't do any traffic engineering on it or influence the way upstream ISP route traffic to you. From the hobbyist point view it would be extremely boring. What can you actually do with it? View the global routing table? You can do this without ever running BGP by using a public looking glass server[1]. There is no incentive for ISP whose business is selling internet connectivity to cultivate a hobbyist community.

[1] https://www.bgp4.as/looking-glasses

Re: "BGP at home": getting a DIA circuit installed at home

#86

Post by bogomipz »

ctime wrote: post #79
throwaway894345 wrote: post #74

Earlier quoted context omitted.

I have a super rudimentary understanding of what BGP is (it allows you to advertise addresses something something), but I don't really understand why it's useful and thus I'm finding TFA to be a little inaccessible. Could you provide some context about what you're using BGP for (what is your use case; what does it enable for you; etc) such that it might fill in some gaps for me?

The internet is a decentralized collection of autonomous systems (AS) and the primary benefit of this setup isn’t exactly realized afaict, which is multiple paths via different carriers. Your BGP AS is advertised via N paths, so your IP networks are thus reachable via multiple paths. Systems will take the shortest/best path adding to redundancy and throughput. Compared that to “business” service without routing optio…

>"The internet is a decentralized collection of autonomous systems (AS) and the primary benefit of this setup isn’t exactly realized afaict, which is multiple paths via different carriers."

The primary benefit if fully-realized and is not about "is multiple paths via different carriers."

An AS is an administrative entity. Route prefixes belong to an AS. All routes with an AS have a common routing policy that is managed by a single entity. I can look up a prefix to find it's AS and then I can look up that AS's routing policies. Here is an example for Tier 1 ISP Spring:

https://www.sprint.net/policies/bgp

I could have single ISP that I buy transit from and I might have multiple links with them. If I want to understand how to take advantage of that for example with traffic engineering then I would look the policies for ISPs AS. I would then use those BGP community attributes on my BGP links to them in order to accomplish my own routing goals.

Re: "BGP at home": getting a DIA circuit installed at home

#87

Post by bogomipz »

linsomniac wrote: post #77
throwaway894345 wrote: post #74

Earlier quoted context omitted.

I have a super rudimentary understanding of what BGP is (it allows you to advertise addresses something something), but I don't really understand why it's useful and thus I'm finding TFA to be a little inaccessible. Could you provide some context about what you're using BGP for (what is your use case; what does it enable for you; etc) such that it might fill in some gaps for me?

BGP is what "the Internet" uses to say what IP addresses can be reached over the various network links that connect different providers. If you had links to two different providers, you would talk BGP to them and say "You can reach this set of IP addresses via me." They then propagate that announcement on to other providers that they connect to. This is done via ASNs (Autonomous Systems Numbers), like 32150 (my old A…

>"If you had links to two different providers, you would talk BGP to them and say "You can reach this set of IP addresses via me."

There is really need to do this is many cases though. If all you are looking for is connectivity redundancy you can just take the default routes from two ISPs and configure floating static routes on your router and not worry about BGP at all.

>"This is done via ASNs (Autonomous Systems Numbers), like 32150 (my old ASN). Each hop along the way gets their ASN tacked on. It's like a flood-fill to all the BGP routers in the world."

Each hop does not get its own ASN tacked on. This only happens when crossing an AS boundary i.e at eBGP speaker. There are generally many hops inside an AS.

Re: "BGP at home": getting a DIA circuit installed at home

#88

Post by bogomipz »

lukeh wrote: post #3

Why two NIDs?

First "NID" is a Telco term of art, it's a contractual concern more than anything else.

The first device terminates the Fiber. It has an SPF transceiver in at for the wavelength the customer is getting the service on which is 1310nm. This is pure layer 1. A technician could/would use this "NID" to get a light reading during provisioning and/or troubleshooting. This is the end of the "local loop."

The second device is the one that provides Carrier Ethernet. Carrier Ethernet is like regular Ethernet but with some extensions that allow the provider "OAM"(operation, administration and management) capabilities. This is a layer 2 device.

Re: "BGP at home": getting a DIA circuit installed at home

#89

Post by hattmall »

icedchai wrote: post #84
Habgdnv wrote: post #64

I've been running BGP at home for the last 10 years, and in my area, most ISPs prefer to use Dedicated Internet Access (DIA) for BGP sessions. Fortunately, I live in a place where there are a few smaller ISPs with around 2000-3000 customers that are willing to run BGP with me as a home user. They're impressed that I have BGP, ASN, and IPs as a home user, and I think it's pretty cool too. Additionally, running one mor…

You're lucky. There are basically no small ISPs around here anymore. It's the cable company (DOCSIS) or telco (fiber, or DSL if you're unlucky.) Without paying for an enterprise grade connection, it would be impossible to get a BGP session through either. I also have a /24 for myself. I've had it since the mid-90's, from the InterNIC days, predating ARIN. I've gone years without using any of the addresses. Currently…

I have a /24 as well, can you point me to any links or tutorials of how I can actually use it with my home connections

Re: "BGP at home": getting a DIA circuit installed at home

#90

Post by icedchai »

hattmall wrote: post #89
icedchai wrote: post #84

Earlier quoted context omitted.

You're lucky. There are basically no small ISPs around here anymore. It's the cable company (DOCSIS) or telco (fiber, or DSL if you're unlucky.) Without paying for an enterprise grade connection, it would be impossible to get a BGP session through either. I also have a /24 for myself. I've had it since the mid-90's, from the InterNIC days, predating ARIN. I've gone years without using any of the addresses. Currently…

I have a /24 as well, can you point me to any links or tutorials of how I can actually use it with my home connections

This person has a good overview: https://varunpriolkar.com/2018/12/bgp-on-a-shoestring-the-de...

Basically, you get an ASN, find a BGP-friendly VPS or colo, announce your /24, and tunnel it back to your home.

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