07-01-2015 09:28 AM - edited 03-08-2019 12:48 AM
Can you connect an Arista switch using their MLAG technology to a nexus 5K or 2K using vPC?
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07-02-2015 05:58 AM
Cisco vPC to Arista MLAG works fine in my experience. I've used Cisco vPC to Arista MLAG using only two links as you're proposing, and also four links e.g., Nexus 1 to Arista 1 and 2, Nexus 2 to Arista 1 and 2.
Here's a sample configuration for the two link option. I have port-channel 1 as the peer link (for both Cisco and Arista) and port-channel 200 as the link between the Cisco and Arista:
! Arista 1 ! vlan 4094 trunk group MLAG_Peer ! interface Vlan4094 ip address 172.17.255.1/30 ! mlag configuration domain-id MLAG1 local-interface Vlan4094 peer-address 172.17.255.2 peer-link Port-Channel1 ! interface Port-Channel1 switchport mode trunk switchport trunk group MLAG_Peer ! interface Ethernet47 channel-group 1 mode active ! interface Ethernet48 channel-group 1 mode active ! interface Port-Channel200 switchport mode trunk mlag 200 ! interface Ethernet10 switchport mode trunk channel-group 200 mode active ! |
! Arista 2 ! vlan 4094 trunk group MLAG_Peer ! interface Vlan4094 ip address 172.17.255.2/30 ! mlag configuration domain-id MLAG1 local-interface Vlan4094 peer-address 172.17.255.1 peer-link Port-Channel1 ! interface Port-Channel1 switchport mode trunk switchport trunk group MLAG_Peer ! interface Ethernet47 channel-group 1 mode active ! interface Ethernet48 channel-group 1 mode active ! interface Port-Channel200 switchport mode trunk mlag 200 ! interface Ethernet10 switchport mode trunk channel-group 200 mode active ! |
# Nexus 5K1 # interface mgmt0 vrf member management ip address 192.168.1.7/25 # feature vpc # vpc domain 11 peer-switch role priority 1 peer-keepalive destination 192.168.1.8 delay restore 60 peer-gateway # interface port-channel1 switchport mode trunk spanning-tree port type network vpc peer-link # interface Ethernet2/1 switchport mode trunk channel-group 1 mode active # interface Ethernet2/2 switchport mode trunk channel-group 1 mode active # interface port-channel200 switchport mode trunk vpc 200 # interface Ethernet1/27 switchport mode trunk channel-group 200 mode active # |
# Nexus 5K2 # interface mgmt0 vrf member management ip address 192.168.1.8/25 # feature vpc # vpc domain 11 peer-switch role priority 1 peer-keepalive destination 192.168.1.7 delay restore 60 peer-gateway # interface port-channel1 switchport mode trunk spanning-tree port type network vpc peer-link # interface Ethernet2/1 switchport mode trunk channel-group 1 mode active # interface Ethernet2/2 switchport mode trunk channel-group 1 mode active # interface port-channel200 switchport mode trunk vpc 200 # interface Ethernet1/27 switchport mode trunk channel-group 200 mode active # |
And here's a couple of show commands on the Arista for good measure:
a7150s-1#sh mlag MLAG Configuration: domain-id : MLAG1 local-interface : Vlan4094 peer-address : 172.17.255.2 peer-link : Port-Channel1 MLAG Status: state : Active negotiation status : Connected peer-link status : Up local-int status : Up system-id : 02:1c:73:42:6d:31 MLAG Ports: Disabled : 0 Configured : 0 Inactive : 0 Active-partial : 0 Active-full : 1 a7150s-1#sh mlag interfaces local/remote mlag desc state local remote status ---------- ---------- ----------------- ----------- ------------ ------------ 200 active-full Po200 Po200 up/up a7150s-1#sh mlag interfaces detail local/remote mlag state local remote oper config last change changes --------- ---------------- ----------- ------------ ----------- ------------- ------------------------- ------- 200 active-full Po200 Po200 up/up ena/ena 1 day, 22:30:04 ago 14 a7150s-1#show port-channel 200 traffic ChanId Port Rx-Ucst Tx-Ucst Rx-Mcst Tx-Mcst Rx-Bcst Tx-Bcst ------ --------- ------- ------- ------- ------- ------- ------- 200 Et10 42.27% 0.00% 46.62% 16.29% 0.00% 100.00% a7150s-2#show port-channel 200 traffic ChanId Port Rx-Ucst Tx-Ucst Rx-Mcst Tx-Mcst Rx-Bcst Tx-Bcst ------ --------- ------- ------- ------- ------- ------- ------- 200 Et10 29.51% 81.42% 53.13% 6.64% 100.00% 100.00%
Regards
07-24-2015 02:51 AM
Hi,
I've connected switches off Nexus 2K host interfaces, but not Nexus 2232. I've only done this as a last resort to connect legacy blade switches at 1GE to Nexus 2248T.
As you're probably aware, the FEX operates with Spanning Tree BPDU Guard on the host interfaces, and unless it's changed in recent releases, this cannot be disabled.
What that means is that to connect a switch to a FEX you need to enable Spanning Tree BPDU filter (spanning-tree bpdufilter enable). This essentially disables Spanning Tree on the interface and can obviously be a little dangerous as any loop that was introduced would never be blocked.
If you're absolutely certain there can be no loops introduced this is an option, but I'd consider it only when there are no other options.
Personally I'd rather try and use ports on the Nexus 5K directly and run in a supported and standard approach than connect the Arista to a FEX and have to disable spanning tree.
Regards
07-01-2015 01:42 PM
So, your design is one Arista switch and 2 Cisco Nexus 5ks or 2 Arista switches?
07-01-2015 01:56 PM
The design is 2 Arista switches and 2 Cisco Nexus 5K. Each Arista has one connection to each Nexus switch.
07-02-2015 05:58 AM
Cisco vPC to Arista MLAG works fine in my experience. I've used Cisco vPC to Arista MLAG using only two links as you're proposing, and also four links e.g., Nexus 1 to Arista 1 and 2, Nexus 2 to Arista 1 and 2.
Here's a sample configuration for the two link option. I have port-channel 1 as the peer link (for both Cisco and Arista) and port-channel 200 as the link between the Cisco and Arista:
! Arista 1 ! vlan 4094 trunk group MLAG_Peer ! interface Vlan4094 ip address 172.17.255.1/30 ! mlag configuration domain-id MLAG1 local-interface Vlan4094 peer-address 172.17.255.2 peer-link Port-Channel1 ! interface Port-Channel1 switchport mode trunk switchport trunk group MLAG_Peer ! interface Ethernet47 channel-group 1 mode active ! interface Ethernet48 channel-group 1 mode active ! interface Port-Channel200 switchport mode trunk mlag 200 ! interface Ethernet10 switchport mode trunk channel-group 200 mode active ! |
! Arista 2 ! vlan 4094 trunk group MLAG_Peer ! interface Vlan4094 ip address 172.17.255.2/30 ! mlag configuration domain-id MLAG1 local-interface Vlan4094 peer-address 172.17.255.1 peer-link Port-Channel1 ! interface Port-Channel1 switchport mode trunk switchport trunk group MLAG_Peer ! interface Ethernet47 channel-group 1 mode active ! interface Ethernet48 channel-group 1 mode active ! interface Port-Channel200 switchport mode trunk mlag 200 ! interface Ethernet10 switchport mode trunk channel-group 200 mode active ! |
# Nexus 5K1 # interface mgmt0 vrf member management ip address 192.168.1.7/25 # feature vpc # vpc domain 11 peer-switch role priority 1 peer-keepalive destination 192.168.1.8 delay restore 60 peer-gateway # interface port-channel1 switchport mode trunk spanning-tree port type network vpc peer-link # interface Ethernet2/1 switchport mode trunk channel-group 1 mode active # interface Ethernet2/2 switchport mode trunk channel-group 1 mode active # interface port-channel200 switchport mode trunk vpc 200 # interface Ethernet1/27 switchport mode trunk channel-group 200 mode active # |
# Nexus 5K2 # interface mgmt0 vrf member management ip address 192.168.1.8/25 # feature vpc # vpc domain 11 peer-switch role priority 1 peer-keepalive destination 192.168.1.7 delay restore 60 peer-gateway # interface port-channel1 switchport mode trunk spanning-tree port type network vpc peer-link # interface Ethernet2/1 switchport mode trunk channel-group 1 mode active # interface Ethernet2/2 switchport mode trunk channel-group 1 mode active # interface port-channel200 switchport mode trunk vpc 200 # interface Ethernet1/27 switchport mode trunk channel-group 200 mode active # |
And here's a couple of show commands on the Arista for good measure:
a7150s-1#sh mlag MLAG Configuration: domain-id : MLAG1 local-interface : Vlan4094 peer-address : 172.17.255.2 peer-link : Port-Channel1 MLAG Status: state : Active negotiation status : Connected peer-link status : Up local-int status : Up system-id : 02:1c:73:42:6d:31 MLAG Ports: Disabled : 0 Configured : 0 Inactive : 0 Active-partial : 0 Active-full : 1 a7150s-1#sh mlag interfaces local/remote mlag desc state local remote status ---------- ---------- ----------------- ----------- ------------ ------------ 200 active-full Po200 Po200 up/up a7150s-1#sh mlag interfaces detail local/remote mlag state local remote oper config last change changes --------- ---------------- ----------- ------------ ----------- ------------- ------------------------- ------- 200 active-full Po200 Po200 up/up ena/ena 1 day, 22:30:04 ago 14 a7150s-1#show port-channel 200 traffic ChanId Port Rx-Ucst Tx-Ucst Rx-Mcst Tx-Mcst Rx-Bcst Tx-Bcst ------ --------- ------- ------- ------- ------- ------- ------- 200 Et10 42.27% 0.00% 46.62% 16.29% 0.00% 100.00% a7150s-2#show port-channel 200 traffic ChanId Port Rx-Ucst Tx-Ucst Rx-Mcst Tx-Mcst Rx-Bcst Tx-Bcst ------ --------- ------- ------- ------- ------- ------- ------- 200 Et10 29.51% 81.42% 53.13% 6.64% 100.00% 100.00%
Regards
07-23-2015 11:29 AM
Just discovered the Arista switches are connecting to Nexus 2232(FEX) off a N5K. I know the 2232 is not designed for switch connectivity. Do you have any experience connecting to 2232. I have connectivity but the vlans on the trunk are not forwarding.
07-24-2015 02:51 AM
Hi,
I've connected switches off Nexus 2K host interfaces, but not Nexus 2232. I've only done this as a last resort to connect legacy blade switches at 1GE to Nexus 2248T.
As you're probably aware, the FEX operates with Spanning Tree BPDU Guard on the host interfaces, and unless it's changed in recent releases, this cannot be disabled.
What that means is that to connect a switch to a FEX you need to enable Spanning Tree BPDU filter (spanning-tree bpdufilter enable). This essentially disables Spanning Tree on the interface and can obviously be a little dangerous as any loop that was introduced would never be blocked.
If you're absolutely certain there can be no loops introduced this is an option, but I'd consider it only when there are no other options.
Personally I'd rather try and use ports on the Nexus 5K directly and run in a supported and standard approach than connect the Arista to a FEX and have to disable spanning tree.
Regards
07-24-2015 09:16 AM
Thanks. I knew about that and we found out that it does cause issues so we will be running to N5K.
07-02-2015 08:23 AM
Thanks. that's the confirmation I needed.
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