1000v SVS layer 3 mode and ERSPAN

[davidcheung]

Hi all,

We are deploying SVS layer 3 mode on nexus1000v and we are considering to use ERSPAN on the same 1000v as well.

We want to seperate the vsm traffic and ERSPAN traffic so we will build two layer3 capability support VMkernal interfaces.

One question come into my mind:

Due to ERSPAN configuration won't identify GRE sourec IP, how 1000v VEM know which VMkernal interface to use for ERSPAN?

Any response is highly appreciated.

Best Regards,

[zmeng]

Hi David,

when you configure ERSPAN, you need to configure an ERSPAN port-profile on N1K and apply the port-profile to already configured vmkernel interface used for ERSPAN, by which VEM will use the special interface for ERSPAN traffic.

Please reference below doc:

http://www.cisco.com/en/US/docs/switches/datacenter/nexus1000/sw/4_2_1_s_v_1_4_a/system_management/configuration/guide/n1000v_system_9span.html

BR,

John Meng

[davidcheung]

Hi John,

Thank you very much for prompt response

Possibly my question confused you.

Let us be more specific:

My ERSPAN and SVSL3 port-profile config as below

port-profile type vethernet ERSPAN
capability l3control
vmware port-group
switchport mode access
switchport access vlan 100
no shutdown
system vlan 100
state enabled

port-profile type vethernet SVSL3

capability l3control

vmware port-group

switchport mode access

switchport access vlan 200

no shutdown

system vlan 200

state enabled

----------------------------------------------

vmk1 for ERSPAN:

IP: 10.1.1.1  (vlan 100)

vmk2 for SVS layer 3 mode:

IP 10.1.2.1  (vlan 200)

====================================

ERSPAN config

monitor session 1 type erspan-source
  source interface Vethernet1 both
  destination ip 10.1.3.199
  erspan-id 100
  ip ttl 64
  ip prec 0
  ip dscp 0
  mtu 1500
  header-type 2
  no shut

==========================================================

So from the above config, how ERSPAN knows which vmk interface to use for ERSPAN traffic source IP if there are connectivity to 10.1.3.199 from both vmk interfaces?

[dersoz · Accepted solution]

Hi David,

N1000v does not support two VMKNics with l3control capability on the same host. You should only configure one and thes ERSPAN and L3control traffic will share the same VMKNic for forwarding.

Let me know if you have any more questions on this.

Thanks,

Deniz

[davidcheung]

Hi Deniz,

Thank you very much!

BG