EVPN for VXLAN in EVPN tunnel R-VPLS services

Figure: EVPN-tunnel gateway IRB on the DC PE for an L3 EVPN/VXLAN DC shows an L3 connectivity model that optimizes the solution described in EVPN for VXLAN in IRB backhaul R-VPLS services and IP prefixes. Instead of regular IRB backhaul R-VPLS services for the connectivity of all the VPRN IRB interfaces, EVPN tunnels can be configured. The main advantage of using EVPN tunnels is that they do not need the configuration of IP addresses, as regular IRB R-VPLS interfaces do.

In addition to the ip-route-advertisement command, this model requires the configuration of the config>service>vprn>if>vpls <name> evpn-tunnel.

Note: The evpn-tunnel can be enabled independently of ip-route-advertisement, however, no route-type 5 advertisements are sent or processed in that case. Neither command, evpn-tunnel and ip-route-advertisement, is supported on R-VPLS services linked to IES interfaces.

The example below shows a VPRN (500) with an EVPN-tunnel R-VPLS (504):

vprn 500 customer 1 create
            ecmp 4
            route-distinguisher 65071:500
            vrf-target target:65000:500
            interface "evi-504" create
                vpls "evpn-vxlan-504"
                    evpn-tunnel
                exit
            exit
            no shutdown
        exit
        vpls 504 name ‟evpn-vxlan-504” customer 1 create
            allow-ip-int-bind
            vxlan instance 1 vni 504 create
            exit
            bgp
                route-distinguisher 65071:504
                route-target export target:65000:504 import target:65000:504
            exit
            bgp-evpn
                ip-route-advertisement
                vxlan bgp 1 vxlan-instance 1
                    no shutdown
                exit
            exit
            no shutdown
        exit

A specified VPRN supports regular IRB backhaul R-VPLS services as well as EVPN tunnel R-VPLS services.

Note: EVPN tunnel R-VPLS services do not support SAPs or SDP-binds.

The process followed upon receiving a route-type 5 on a regular IRB R-VPLS interface differs from the one for an EVPN-tunnel type:

*A:PE71# show router 500 route-table 
===============================================================================
Route Table (Service: 500)
===============================================================================
Dest Prefix[Flags]                            Type    Proto     Age        Pref
      Next Hop[Interface Name]                                    Metric   
-------------------------------------------------------------------------------
10.20.20.72/32                                Remote  BGP EVPN  00h23m50s  169
       10.10.10.72                                                  0
10.30.30.0/24                                 Remote  BGP EVPN  01d11h30m  169
       evi-504 (ET-d8:45:ff:00:01:35)                               0
10.10.10.0/24                                Remote  BGP VPN   00h20m52s  170
       192.0.2.69 (tunneled)                                        0
10.1.0.0/16                                  Remote  BGP EVPN  00h22m33s  169
       evi-504 (ET-d8:45:ff:00:01:35)                               0
-------------------------------------------------------------------------------
No. of Routes: 4

The GW-MAC as well as the rest of the IP prefix BGP attributes are displayed by the show router bgp routes evpn ip-prefix command.

*A:Dut-A# show router bgp routes evpn ip-prefix prefix 3.0.1.6/32 detail
===============================================================================
BGP Router ID:10.20.1.1        AS:100         Local AS:100       
===============================================================================
Legend -
Status codes  : u - used, s - suppressed, h - history, d - decayed, * - valid
Origin codes  : i - IGP, e - EGP, ? - incomplete, > - best, b - backup
 
===============================================================================
BGP EVPN IP-Prefix Routes
===============================================================================
-------------------------------------------------------------------------------
Original Attributes
 
Network        : N/A
Nexthop        : 10.20.1.2
From           : 10.20.1.2
Res. Nexthop   : 192.168.19.1
Local Pref.    : 100                    Interface Name : NotAvailable
Aggregator AS  : None                   Aggregator     : None
Atomic Aggr.   : Not Atomic             MED            : 0
AIGP Metric    : None                  
Connector      : None
Community      : target:100:1 mac-nh:00:00:01:00:01:02
                 bgp-tunnel-encap:VXLAN
Cluster        : No Cluster Members
Originator Id  : None                   Peer Router Id : 10.20.1.2
Flags          : Used  Valid  Best  IGP 
Route Source   : Internal              
AS-Path        : No As-Path
EVPN type      : IP-PREFIX             
ESI            : N/A                    Tag            : 1
Gateway Address: 00:00:01:00:01:02     
Prefix         : 3.0.1.6/32             Route Dist.    : 10.20.1.2:1
MPLS Label    : 262140
Route Tag      : 0xb
Neighbor-AS    : N/A
Orig Validation: N/A                   
Source Class   : 0                      Dest Class     : 0
 
Modified Attributes
 
Network        : N/A                 
Nexthop        : 10.20.1.2
From           : 10.20.1.2
Res. Nexthop   : 192.168.19.1
Local Pref.    : 100                    Interface Name : NotAvailable
Aggregator AS  : None                   Aggregator     : None
Atomic Aggr.   : Not Atomic             MED            : 0
AIGP Metric    : None                  
Connector      : None
Community      : target:100:1 mac-nh:00:00:01:00:01:02
                 bgp-tunnel-encap:VXLAN
Cluster        : No Cluster Members
Originator Id  : None                   Peer Router Id : 10.20.1.2
Flags          : Used  Valid  Best  IGP 
Route Source   : Internal              
AS-Path        : 111
EVPN type      : IP-PREFIX             
ESI            : N/A                    Tag            : 1
Gateway Address: 00:00:01:00:01:02     
Prefix         : 3.0.1.6/32             Route Dist.    : 10.20.1.2:1
MPLS Label    : 262140
Route Tag      : 0xb
Neighbor-AS    : 111
Orig Validation: N/A                   
Source Class   : 0                      Dest Class     : 0
 
-------------------------------------------------------------------------------
Routes : 1
===============================================================================

EVPN tunneling is also supported on IPv6 VPRN interfaces. When sending IPv6 prefixes from IPv6 interfaces, the GW-MAC in the route type 5 (IP-prefix route) is always zero. If no specific Global Address is configured on the IPv6 interface, the routes type 5 for IPv6 prefixes are always sent using the Link Local Address as GW-IP. The following example output shows an IPv6 prefix received through BGP EVPN.

*A:PE71# show router 30 route-table ipv6 
 
===============================================================================
IPv6 Route Table (Service: 30)
===============================================================================
Dest Prefix[Flags]                            Type    Proto     Age        Pref
      Next Hop[Interface Name]                                    Metric   
-------------------------------------------------------------------------------
2001:db8:1000::/64                            Local   Local     00h01m19s  0
       int-PE-71-CE-1                                               0
2001:db8:2000::1/128                          Remote  BGP EVPN  00h01m20s  169
       fe80::da45:ffff:fe00:6a-"int-evi-301"                        0
-------------------------------------------------------------------------------
No. of Routes: 2
Flags: n = Number of times nexthop is repeated
       B = BGP backup route available
       L = LFA nexthop available
       S = Sticky ECMP requested
===============================================================================
 
*A:PE71# show router bgp routes evpn ipv6-prefix prefix 2001:db8:2000::1/128 hunt 
===============================================================================
 BGP Router ID:192.0.2.71       AS:64500       Local AS:64500      
===============================================================================
 Legend -
 Status codes  : u - used, s - suppressed, h - history, d - decayed, * - valid
                 l - leaked
 Origin codes  : i - IGP, e - EGP, ? - incomplete, > - best, b - backup
 
===============================================================================
BGP EVPN IP-Prefix Routes
===============================================================================
-------------------------------------------------------------------------------
RIB In Entries
-------------------------------------------------------------------------------
Network        : N/A
Nexthop        : 192.0.2.69
From           : 192.0.2.69
Res. Nexthop   : 192.168.19.2
Local Pref.    : 100                    Interface Name : int-71-69
Aggregator AS  : None                   Aggregator     : None
Atomic Aggr.   : Not Atomic             MED            : 0
AIGP Metric    : None                   
Connector      : None
Community      : target:64500:301 bgp-tunnel-encap:VXLAN
Cluster        : No Cluster Members
Originator Id  : None                   Peer Router Id : 192.0.2.69
Flags          : Used  Valid  Best  IGP  
Route Source   : Internal
AS-Path        : No As-Path
EVPN type      : IP-PREFIX              
ESI            : N/A                    Tag            : 301
Gateway Address: fe80::da45:ffff:fe00:* 
Prefix         : 2001:db8:2000::1/128   Route Dist.    : 192.0.2.69:301
MPLS Label     : 0                      
Route Tag      : 0                      
Neighbor-AS    : N/A
Orig Validation: N/A                    
Source Class   : 0                      Dest Class     : 0
Add Paths Send : Default                
Last Modified  : 00h41m17s              
 
-------------------------------------------------------------------------------
RIB Out Entries
-------------------------------------------------------------------------------
-------------------------------------------------------------------------------
Routes : 1
===============================================================================