Peering with AS larger than 65535

[johnelliot6]

Hi,

Have an oldish 7200-G2 in the lab that I need to setup with test peering with an AS larger than 65535 - It does not accept asdot notation (i.e. throws an error when I enter the converted AS - It doesnt like the ".").

Is there any work-around to this? (Aside from IOS upgrade)

Cheers.

[sean_evershed]

So do you have control of the other router?

If so I have never tried it but dual AS may work:

http://www.cisco.com/c/en/us/td/docs/ios/12_2s/feature/guide/fsbgpdas.html#wp1044665

[Giuseppe Larosa]

Hello John,

if your objective is to test an eBGP peering with a 32 bit AS peer and the C7200-G2 has to play that role you need an IOS upgrade.

Releases 12.0(32)S11, 12.0(33)S, 12.0(32)SY

Cisco 7200 Series

to build an EBGP session between the C7200 and another 32bit AS capable device there is a special 16 bit AS number for backward compatibility.

 newly reserved AS TRANS# 23456 for interoperability between 4-byte ASN capable and non-capable BGP speakers

see

http://www.cisco.com/c/en/us/products/collateral/ios-nx-os-software/border-gateway-protocol-bgp/data_sheet_C78-521821.html

Hope to help

Giuseppe