12-14-2017 12:51 PM - last edited on 03-25-2019 03:50 PM by ciscomoderator
I am wondering what type of addressing ( public or private ) is used when connecting two AS:
let us say i have a midsize company, i got a public ASN and i want to run eBGP between my CE Router and the upstream Service Provider to advertise a network. in this case what type of ip addresses i use on the link(s) that connect me with the ISP(s)
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12-17-2017 09:18 AM - edited 12-17-2017 09:19 AM
Hello
you will require public address when using two separate isps - as I stated you also need public ASN
the reason being is that they both need to advertise your address space to their own peers which 9/10 would be a summary of the what they give you
res
paul
12-14-2017 01:04 PM
Hello,
the short answer is: it is not your choice. You will get the (public) IP addresses from your ISP.
12-14-2017 01:18 PM
12-14-2017 01:40 PM
Hello,
sorry for the confusion: which network do you want to advertise ? You only need a public IP address when you are advertising a public network...
Can you draw up what your setup looks like ?
12-14-2017 02:50 PM
i mean the ip addresses that set on the interfaces f0/0 in the attached photo, should they be public or private ??
12-15-2017 12:06 AM
Hello,
AS24 and AS40 are public AS numbers, you only need those if you have Internet access. So you need to connect them with public IP addresses on the FastEthernet interfaces.
12-15-2017 05:18 AM - edited 12-15-2017 05:19 AM
Hello
It all depends on if the ASN need to be a registered one - it doesn't have to be?
If you are going to connect to two different ISP's then your site would need to be registered between ASN 1-64511
However is you need to connect to a single ISP ( single or dual homed connection) then the ASN can be a private one - 64512 -65535 - Now any update to the ISP from your site will include its private ASN, thus the isp will remove this from the as-path it advertised to nay of it peers.
res
Paul
12-15-2017 07:35 PM
Dear Paul;
Kindly note that my question was about the ip addresses ( and not the ASN number) needed to be assigned to the interfaces f0/0 on both side of the link that connect the two autonomous systems, those IPs, do they need to be public or not ?
Thanks in advance.
12-17-2017 09:18 AM - edited 12-17-2017 09:19 AM
Hello
you will require public address when using two separate isps - as I stated you also need public ASN
the reason being is that they both need to advertise your address space to their own peers which 9/10 would be a summary of the what they give you
res
paul
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