EVPN ARP/ND Suppression Follow

Overview:

ARP Suppression will help to reply the arp request if the arp exist in arp table. It could help to save the needless arp traffic.

Example:

• ARP Suppression run with vxlan solution.

Reference model:

• Switch model name:

- AS7726-32X

- AS7326-56X

- AS5835-54X(T)

- AS4630-54PE

• Edgecore SONiC version: 

- Edgecore-SONiC_20201123_130028_ec202006_74

- Edgecore-SONiC_20201229_070315_ec202006_101

Example : ARP Suppression with SAG running on vxlan service.

Topology:

Procedure:

Step 1. Init FRR and set the loopback interface(reference Management port and front port ipv4/ipv6 and FRR init)

Step 2. Create the Vlan and ip binding as topology

ND1:

admin@sonic:~$ sudo config vlan add 100
admin@sonic:~$ sudo config vlan member add -u 100 Ethernet0
admin@sonic:~$ sudo config sag mac_address add 00:11:22:33:44:55
admin@sonic:~$ sudo config sag ipv4 enable
admin@sonic:~$ sudo config interface sag ip add Vlan100 192.168.100.11/24
admin@sonic:~$ sudo config interface ip add Ethernet56 10.0.0.0/31

ND2:

admin@sonic:~$ sudo config vlan add 100
admin@sonic:~$ sudo config vlan member add 100 Ethernet0
admin@sonic:~$ sudo config sag mac_address add 00:11:22:33:44:55
admin@sonic:~$ sudo config sag ipv4 enable
admin@sonic:~$ sudo config interface sag ip add Vlan100 192.168.100.12/24
admin@sonic:~$ sudo config interface ip add Ethernet56 10.0.0.1/31

Step 3. Create Vxlan interface

ND1:

admin@sonic:~$ sudo config vxlan add vtep 1.1.1.1
admin@sonic:~$ sudo config vxlan evpn_nvo add nvo vtep
admin@sonic:~$ sudo config vxlan map add vtep 100 100

ND2:

admin@sonic:~$ sudo config vxlan add vtep 2.2.2.2
admin@sonic:~$ sudo config vxlan evpn_nvo add nvo vtep
admin@sonic:~$ sudo config vxlan map add vtep 100 100

Step 4. Enable ARP/ND suppress

ND1 and ND2:

admin@sonic:~$ sudo config neigh_suppress enable 100

Step 5. Set the EVPN on FRR.

ND1:

sonic# configure
sonic(config)# router bgp 65100
sonic(config-router)# neighbor Ethernet56 interface remote-as internal
sonic(config-router)# bgp router-id 1.1.1.1
sonic(config-router)# address-family ipv4
sonic(config-router-af)# redistribute connected
sonic(config-router-af)# exit
sonic(config-router)# address-family l2vpn evpn
sonic(config-router-af)# advertise-all-vni
sonic(config-router-af)# neighbor Ethernet56 activate

ND2:

sonic# configure
sonic(config)# router bgp 65100
sonic(config-router)# neighbor Ethernet56 interface remote-as internal
sonic(config-router)# bgp router-id 2.2.2.2
sonic(config-router)# address-family ipv4
sonic(config-router-af)# redistribute connected
sonic(config-router-af)# exit
sonic(config-router)# address-family l2vpn evpn
sonic(config-router-af)# advertise-all-vni
sonic(config-router-af)# neighbor Ethernet56 activate

Step 6. Check the neighbor suppress

ND1:

admin@sonic:~$ show neigh-suppress vlan 100
+---------+------------+---------------------+
| VLAN    | STATUS     | ASSOCIATED_NETDEV   |
+=========+============+=====================+
| Vlan100 | Configured | vtep-100            |
+---------+------------+---------------------+

ND2:

admin@sonic:~$ show neigh-suppress vlan 100
+---------+------------+---------------------+
| VLAN    | STATUS     | ASSOCIATED_NETDEV   |
+=========+============+=====================+
| Vlan100 | Configured | vtep-100            |
+---------+------------+---------------------+

Step 7. Ping from Switch#1 to ND1

Step 8. Ping from Switch#2 to Switch1, we can't find arp request on Switch#1 from Switch#2. The ARP reply will be send by ND2.