Remove 4 Byte BGP Private ASN

[network2004@gmail.com]

How do you remove 4 byte Private BGP ASN as you advertise the prefixes to your ISP?

I already tried neighbor x.x.x.x remove-private-as command.  This command only removes 2 byte private BGP ASN.

Within my environment, we use both 2 byte private ASN and 4 byte private ASN.  On our border router to the ISP, we use the above command and it looks like it only works for 2 byte private ASN and not the 4 byte ones.

Thanks for the help. 

[inderdeeps]

network2004@gmail.com : Are you using asnotation for 4 Byte BGP number ?

[network2004@gmail.com]

I briefly read about it and I am not sure what asnotation does.  Could you explain how to use asnotation?  thanks.

[inderdeeps]

network2004@gmail.com : there are two types of notation, ASplain and ASdot. check out and if you think my post helps, please vote 

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst9400/software/release/16-12/configuration_guide/rtng/b_1612_rtng_9400_cg/configuring_bgp_support_for_4_byte_asn.pdf 

[network2004@gmail.com]

So neighbor x.x.x.x remove-private-as command removes 4 byte private BGP ASN ?

[Giuseppe Larosa · Accepted solution]

Hello network2004@gmail.com ,

what is your border router ?

post a show version

as a workaround you could try to use an aggregate-address with summary-only option as an attempt to remove the 4 bytes private AS numbers from the AS path attribute. This might be possible or not in your scenario.

Hope to help

Giuseppe

[network2004@gmail.com]

Thanks Giuseppe.   Aggregate with summary only is also what I did in the lab too.  I see that Juniper has the option to remove 4 byte private ASN and I just want to double check if Cisco has the same option too.