Issues with 4-octet BGP AS and Akamai?

["Greg Gombas -X (grgombas)" <grgombas () cisco com>]

Hello BGP and/or Akamai experts,

Has anyone come across issues with using the new 4-octet BGP AS number format and reaching websites hosted by Akamai?

One of my customers currently uses the AS number of one of their partner companies, which is in the standard 2-octed AS 
format. They were recently assigned their own AS which is in the 4-octet AS format.

When they advertise their networks using the 2-octet AS number everything works fine, they can browse to all websites 
and all their outbound and inbound internet traffic works perfectly.

However when they stop advertising their networks using the 2-octet AS and advertise their networks using the new 
4-octet AS number, they lose reachability to a number of websites, all of which seem to be hosted by Akamai, including 
www.cisco.com<http://www.cisco.com>, www.dell.com<http://www.dell.com>, and a number of others. Websites that are not 
hosted by Akamai work just fine.

We checked their route advertisements from several looking glass servers and the routes seem to be propagating 
properly, albeit there may be a number of older routers still out there that don't understand the new 4 octet BGP AS 
format.
For example, their AS shows up as AS_TRANS 23456 on some looking glass routers.

My understanding is the 4-octet ASN's have been out for quite some time now, so any interoperability issues should have 
been resolved by now. But could there be some old BGP speakers who don't understand the new format or the translated AS 
23456 format and drop the routes?

Has anyone experienced similar issues when using the new format 4 byte BGP ASN's?

Any thoughts on who at Akamai we can speak to in order to troubleshoot this further?

Thanks,
Greg


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Gregory Gombas
CCIE# 19649 - R&S
Network Consulting Engineer
Advanced Services
grgombas () cisco com<mailto:grgombas () cisco com>
Office: +1-212-714-4497
Mobile: +1-201-675-9457

Cisco Systems Limited
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