BGP and private AS

[Timohamoto]

Hi guys!

What's your advise? (except "get your CCNP")

We are running web site on VM with public IP address.

Company planning to move to other location and get service from 2 different ISP.

To provide failure tolerance I plan to organize BGP with private AS.

Correct me if I wrong:

I do need to regulate number of AS from 64512 to 65535 and lease pool of IP addresses from one ISP and advertise to other one?

Thank you for review and help!

[Dennis Mink]

I think you would need to talk to your providers first and find out what criteria both use to allow you to advertise Public IP addresses into their AS(s).

[johnlloyd_13]

hi,

the AS 64512 to 65535 are private AS numbers (like RFC 1918) and can't be used to peer/do eBGP with upstream service providers.

you should contact your RIR to get/register public ASN. refer useful links:

http://www.iana.org/assignments/as-numbers/as-numbers.xhtml

https://en.wikipedia.org/wiki/Regional_Internet_registry

https://www.icann.org/resources/pages/global-addressing-2012-02-25-en

[Timohamoto]

Hi John!

Somehow it's possible to get rid of private AS number on the side of ISP and place it's own ASN.

Please take a look my answer to Georg.

[Georg Pauwen]

Hello,

just to be sure there is no misunderstanding: you cannot peer with an ISP using a private AS. If you want your router to connect with an ISP, your provider will assign you a public AS. The public range has been extended by using a 4 byte number, so the original public range, AS 1 through 64,495 has now been extended to over 4 billion possible AS numbers.

That said, you provider can strip private AS-numbers from incoming updates, with the remove-private-as peer command, e.g.:

neighbor 1.1.1.1 remove-private-as

[Timohamoto]

Hello, Georg!

Keith Barker told: "You can peer with ISP by using private AS"

I was calling to one of ISP, they told

- Yes, we can do that: "Which number of private AS would you take?"

Another ISP told me: You can peer to us with private AS but you do need take two uplinks to us. - That's how it works.

I did clarify a bit that quetions.

But I did't find the second ISP which would accept just one uplink to them with private AS.

But if I will. Will it works like that: I will lease network /24 from one ISP and advertise it by private AS to other one, or it does't work like what?

[Georg Pauwen]

Hello,

in addition to the other posts, the link below has a pretty straight forward explanation of the necessary steps:

Setting Up a Redundant Internet Connection With BGP

https://www.auvik.com/media/blog/redundant-internet-connection-bgp/

[Timohamoto]

Hi Georg!

Thanks for link, I did read it. But there no clear information about private AS and how ISP strip off private AS number and replacing with their own for further BGP routing.

All I need it just understand how to configure BGP and private AS when I will have two ISP.

And what type of configuration will perform ISP to strip off my private AS.

btw in that situation do I need still to lease PI IP addresses or it's will work with leased IP from ISP?

Here is some pics which I did found from CBT nuggets course  "CCNP R&S" by Keith Barker

And his answer about "strip of private AS number" https://goo.gl/udz8oK