To enable external connectivity, you can configure the remove-private-as attribute when you create or update BGP peer.
By default, remove-private-as is disabled and it is an IPv4 attribute only.
efa tenant service bgp peer create --name <bgp-peer-name> --tenant <tenant-name> 
                   	--ipv4-uc-nbr <device-ip,vrf-name:neighbor-ip,remote-asn> 
                   	--ipv4-uc-nbr-bfd <device-ip,vrf-name:neighbor-ip,true|false> 
                   	--ipv4-uc-nbr-remove-private-as <device-ip,vrf-name:neighbor-ip,true|false>
                efa tenant service bgp peer update --name <bgp-peer-name> --tenant <tenant-name>
 
             --operation peer-add
             --ipv4-uc-nbr 10.20.246.25,v1:10.20.30.50,50000 
		--ipv4-uc-nbr-bfd 10.20.246.25,v1:10.20.30.50,true 
		--ipv4-uc-nbr-remove-private-as 10.20.246.25,v1:10.20.30.50,true 
		--ipv4-uc-nbr 10.20.246.26,v1:10.20.30.50,50000 
		--ipv4-uc-nbr-bfd 10.20.246.26,v1:10.20.30.50,true 
		--ipv4-uc-nbr-remove-private-as 10.20.246.26,v1:10.20.30.50,false 
                    efa tenant service bgp peer create --name ten1bgppeer1 --tenant tenant11 --ipv4-uc-nbr 10.20.246.25,v1:10.20.30.40,50000 --ipv4-uc-nbr-bfd 10.20.246.25,v1:10.20.30.40,true --ipv4-uc-nbr-remove-private-as 10.20.246.25,v1:10.20.30.40,true --ipv4-uc-nbr 10.20.246.26,v1:10.20.30.40,50000 --ipv4-uc-nbr-bfd 10.20.246.26,v1:10.20.30.40,true --ipv4-uc-nbr-remove-private-as 10.20.246.26,v1:10.20.30.40,true
| 10.20.246.25 ORCA_01# show running-config router bgp address-family ipv4 unicast vrf v1 redistribute connected neighbor 10.20.30.40 remote-as 50000 neighbor 10.20.30.40 remove-private-as neighbor 10.20.30.40 bfd neighbor 10.40.40.253 remote-as 4200000000 neighbor 10.40.40.253 next-hop-self maximum-paths 8 ! | 10.20.246.26 ORCA_02# show running-config router bgp address-family ipv4 unicast vrf v1 redistribute connected neighbor 10.20.30.40 remote-as 50000 neighbor 10.20.30.40 remove-private-as neighbor 10.20.30.40 bfd neighbor 10.40.40.252 remote-as 4200000000 neighbor 10.40.40.252 next-hop-self maximum-paths 8 ! | 
| efa tenant service bgp peer show --detail | ||
| Name : ten1bgppeer1 Tenant : tenant11 State : bgp-peer-created Description : Static Peer ----------- Device IP : 10.20.246.25 VRF : v1 AFI : ipv4 SAFI : unicast Remote IP : 10.20.30.40 Remote ASN : 50000 Next Hop Self : false Update Source IP : BFD Enabled : true BFD Interval : 0 BFD Rx : 0 BFD Multiplier : 0 MD5 Password : Remove Private AS : true Default Originate : false Default Originate Route Map : Prefix List In : Prefix List Out : Route Map In : Route Map Out : Dev State : provisioned App State : cfg-in-sync | Device IP : 10.20.246.25 VRF : v1 AFI : ipv4 SAFI : unicast Remote IP : 10.20.30.50 Remote ASN : 50000 Next Hop Self : false Update Source IP : BFD Enabled : true BFD Interval : 0 BFD Rx : 0 BFD Multiplier : 0 MD5 Password : Remove Private AS : true Default Originate : false Default Originate Route Map : Prefix List In : Prefix List Out : Route Map In : Route Map Out : Dev State : provisioned App State : cfg-in-sync Device IP : 10.20.246.26 VRF : v1 AFI : ipv4 SAFI : unicast Remote IP : 10.20.30.50 Remote ASN : 50000 Next Hop Self : false Update Source IP : BFD Enabled : true BFD Interval : 0 BFD Rx : 0 | BFD Multiplier : 0 MD5 Password : Remove Private AS : false Default Originate : false Default Originate Route Map : Prefix List In : Prefix List Out : Route Map In : Route Map Out : Dev State : provisioned App State : cfg-in-sync Device IP : 10.20.246.26 VRF : v1 AFI : ipv4 SAFI : unicast Remote IP : 10.20.30.40 Remote ASN : 50000 Next Hop Self : false Update Source IP : BFD Enabled : true BFD Interval : 0 BFD Rx : 0 BFD Multiplier : 0 MD5 Password : Remove Private AS : true Default Originate : false Default Originate Route Map : Prefix List In : Prefix List Out : Route Map In : Route Map Out : Dev State : provisioned App State : cfg-in-sync | 
| Rack1-Device1# show running-config router bgp router bgp local-as 4200000000 capability as4-enable fast-external-fallover neighbor 10.20.20.4 remote-as 4200000000 neighbor 10.20.20.4 next-hop-self address-family ipv4 unicast network 172.31.254.46/32 network 172.31.254.123/32 maximum-paths 8 graceful-restart ! address-family ipv4 unicast vrf ten1vrf1 redistribute connected neighbor 10.20.30.40 remote-as 50000 neighbor 10.20.30.40 remove-private-as neighbor 10.20.30.40 bfd neighbor 10.20.30.50 remote-as 50000 neighbor 10.20.30.50 remove-private-as neighbor 10.20.30.50 bfd maximum-paths 8 ! address-family ipv6 unicast ! address-family ipv6 unicast vrf ten1vrf1 redistribute connected maximum-paths 8 ! address-family l2vpn evpn graceful-restart ! ! | Rack1-Device2# show running-config router bgp router bgp local-as 4200000000 capability as4-enable fast-external-fallover neighbor 10.20.20.5 remote-as 4200000000 neighbor 10.20.20.5 next-hop-self address-family ipv4 unicast network 172.31.254.46/32 network 172.31.254.176/32 maximum-paths 8 graceful-restart ! address-family ipv4 unicast vrf ten1vrf1 redistribute connected neighbor 10.20.30.40 remote-as 50000 neighbor 10.20.30.40 remove-private-as neighbor 10.20.30.40 bfd neighbor 10.20.30.50 remote-as 50000 neighbor 10.20.30.50 remove-private-as neighbor 10.20.30.50 bfd maximum-paths 8 ! address-family ipv6 unicast ! address-family ipv6 unicast vrf ten1vrf1 redistribute connected maximum-paths 8 ! address-family l2vpn evpn graceful-restart ! ! | 

Note
For information about commands and supported parameters to configure remove-private-as attribute, see Extreme Fabric Automation Command Reference, 3.0.0 .