BGP 4-byte ASN

[madieha]

I want to run a  routing protocols BGP 4-byte. Enable it at device C3750 however i found that it was not compatible/support for BGP 4-byte.

Any devices below that can support BGP 4-byte

1) C3850

2) C3650

3) ENCS 5408/K9

[Harold Ritter · Accepted solution]

Hi @madieha ,

You can use the Cisco Feature Navigator to find out what platform supports a specific feature.

https://cfnng.cisco.com/

Regards,

[madieha]

Hi Harold

Thanks for the feedback and solution. manage to find the features that supported BGP 4-byte using the link that you are provided, 
There is only one device : ENCS 5408/K9 that are still not able find at the webpage.

[MHM Cisco World]

the navigator is not update and it some time not include feature and or platform 
if better to read the guide or as I mention use help see the number of AS you get

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3850/software/release/16-11/configuration_guide/rtng/b_1611_rtng_3850_cg/configuring_bgp_support_for_4_byte_asn.html
MHM

[madieha]

i did try to configure switch model 3850 with IOS 16.12.05b however the not able to configure BGP 4-Byte.
I guess need to use IP services license instead of universal license 

Switch(config)#router bgp ?
<1-4294967295> Autonomous system number <1.0-XX.YY>
Autonomous system number
Switch(config)#router bgp 64088.74
Protocol not in this image


Switch Ports Model SW Version SW Image Mode
------ ----- ----- ---------- ---------- ----
* 1 20 WS-C3850-12S 16.12.05b CAT3K_CAA-UNIVERSALK9 BUNDLE

[MHM Cisco World]

Hi

I think you can use 

Router bgp ?

Check the number of AS you can enter 

Also if your bgp neighbor support 4-bytes and your SW support 2-byte that no problem.

The nieghor with 4-bytes can work with 2-bytes by using AS-Trans

MHM

[madieha]

Hi MHM

Thanks for your inputs!

[Gopinath_Pigili]

Hello  madieha,

BGP Support for 4-byte ASN : Cisco IOS XE Release 2.3, Cisco IOS XE Release 2.4,Cisco IOS XE Release 3.9S

If you want to check your router will support 4-byte AS or not ...

You can use 4-byte AS number in two ways..

• asplain notation
• asdot format 

Here is the sample configuration for asplain notation

router bgp 65536
 bgp router-id 10.1.1.99
 no bgp default ipv4-unicast
 bgp fast-external-fallover
 bgp log-neighbor-changes
 timers bgp 70 120
 neighbor 192.168.1.1 remote-as 65538
 !
 address-family ipv4
  neighbor 192.168.1.1 activate
  no auto-summary
  no synchronization
  network 10.1.1.0 mask 255.255.255.0
  exit-address-family

Here is the sample configuration for asdot format...

router bgp 1.0
 bgp router-id 10.1.1.99
 no bgp default ipv4-unicast
 bgp fast-external-fallover
 bgp log-neighbor-changes
 timers bgp 70 120
 neighbor 192.168.1.1 remote-as 1.2
 !
 address-family ipv4
  neighbor 192.168.1.1 activate
  no auto-summary
  no synchronization
  network 10.1.1.0 mask 255.255.255.0
  exit-address-family

Note: Asplain Default Format in Cisco IOS Release 12.0(32)SY8, 12.0(33)S3, 12.2(33)SRE, 12.2(33)SXI1, and Later Releases...

Best regards
******* If This Helps, Please Rate *******

[madieha]

Thanks Pigili for your input! This also new to me to find based on the IOS release