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New Member

BGP AS# & Public IP assignment query for Gurus..:-)

Hello BGP gurus,

need some clarification on BGP AS# & Public IP space assignments...

If Ripe assigns me a public ip block of 30.24.48.0-30.24.63.255(30.24.24.0/20), then..

1.Can I use individual subnets (30.24.48.0/24, 30.24.49.0/24 etc..) any where in the world as long as my ISP at that place is advertising them..?

2. Also, at those places, incase if I want to advertise my individual subnet via ISP BGP peering, (use BGP for redundancy, load balance via 2ISPs) do I have to request for seperate AS# at each location ..?

3.If I know a AS#, how do I find out, to whom that AS# is assigned to.

4. When RIPE assigns public block, will it also assign AS# or it need to be seperately requested...?

Thats all for now.

Thank you in advance.

MS

6 REPLIES

Re: BGP AS# & Public IP assignment query for Gurus..:-)

1. yes u can use individual subnets as long as only those subnets are advertised by ur ISP & not the Summary.

2. not sure if same AS can be used at multiple locations. Lets see what experts have to say.

3. AS number registrations can be seen from IANA registry.

4. You need to purchase separate AS numbers separately.

hope that helps.

pls rate all helpful posts.

Re: BGP AS# & Public IP assignment query for Gurus..:-)

Hi,

1. Yes you can. You can even advertise an aggregated 30.24.48.0/20 using your own AS# and advertise 30.24.48.0/24 using another AS# (or your ISP AS#) in other part of the world. Because the more specific route still applies.

2. No need, you can advertised them using Private AS#, you just have to talk to your ISP to agree what Private AS# to use.

3. You can check from IANA or use the NICs WHOIS. ARIN, RIPE-NCC, APNIC, AFRINIC, LACNIC.

4. AFAIK they are seperate. The justification for both are different. Read their policy on IP Address block and AS# allocation.

[EDIT] Before you chop-chop your IP Address netblock, check with your upstream ISP (directly connected) the minimum number of netblocks they allow. Some ISP may allow /24 but some may not allow it.

Regards,

Dandy

Re: BGP AS# & Public IP assignment query for Gurus..:-)

Hi,

1. I believe so, but not more specific than /24, for more accuracy contact RIPE.

2. No, but you need some other BGP configuration considerations according to your case.

3. You can query the RIPE database at ripe.net, just write the ASN in this format "ASXXXXX".

4. ASN and IP blocks are separately requested.

http://ripe.net/info/faq/rs/general.html

Finally you can contact RIPE at ripe-dbm@ripe.net, for further details, they are very helpful.

BR,

Mohammed Mahmoud.

New Member

Re: BGP AS# & Public IP assignment query for Gurus..:-)

hi

1. depends on your ISP whether would like to advertise trivial routing(more than 20 bit mask)

2. i`m not sure but i think one AS is enough

3. here we get the AS# from APNIC, i do not know there

4. yes,respectively

regards

dongdong

Re: BGP AS# & Public IP assignment query for Gurus..:-)

Hi,

1- Yes you can.

2- No you dont have to, You will need to have IBGP between your Edge routers.

3- you can Go to RIPE and find any information about AS's associated with Subnets and to whom its assigned.

4- I think you will need to request both , AS and Subnets, (Double check from RIPE).

HTH

Mohamed

New Member

Re: BGP AS# & Public IP assignment query for Gurus..:-)

Thank you all for your replies. All replies are helpful .. :-)

MS

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