MDS IP Control Plane

[meaton-brown]

I'd like to understand where the IP control & forwarding planes resides within the Cisco MDS 9000 Family 14/2-port Multiprotocol Services Module. Due to the low number of GE interfaces per card and for resilience, if FC to IP conversion takes place on one card but the egress GE is unavailable - can the architecture tolerate IP switching to another card and GE port in the same chassis and if so can an IP Routing protocol be used between MDS9506's to determine that as the best contingent path ?

[dmcloon]

There are various approaches that will achieve the resilience you need when a single IPS gigabit Ethernet port goes down.

With Virtual Router Redundancy Protocol (VRRP) running on the IPS blade you will experience iSCSI session drop or FCIP link flap when the backup interface takes over the VRRP ip address.

With Ethernet portchannel you will see no disruption, but the two ports need to be same odd/even pair on same module, eg gig1/1 and 1/2.

Another common approach for FCIP is to create multiple FCIP links/tunnels using different IPS ports and if any one port fails FCIP traffic will not be interrupted. Multiple FCIP links can be bundled into a portchannel.

Please see the MDS Config Guide for more detail.

[meaton-brown]

Understood, however in this scenario the ingress FC and egress GE are on the same card, there are two MDS's for resilience at each end of a DWDM as shown here;

....MDS ==(GE)==DWDM==(GE)==MDS

(GE)|.|..............................................|.|(GE)

....MDS ==(GE)==DWDM==(GE)==MDS

BTW: Ignore the dots, they are space fillers to make the diagram look right

Should the DWDM path fail one MDS, the GE interfaces will drop, ideally we want IP to converge via the other MDS;

1. Can dynamic IP be used such that a FCIP tunnel will pass through another card in the chassis to exit one MDS and tunnel through another ?

2. If a separate card can be used, can GE link two MDS's and facilitate IP forwarding as shown here?

[oerkan · Accepted solution]

Hi Meaton,

If I understand your topology correctly, you have one GE connection to the remote MDS and one to the local MDS.

1) No, fcip tunnel goes down, if the related GE port goes down.

For the fcip, first you need to configure an fcip profile such as :

fcip profile 1

ip address 100.100.100.7 >>ip add. of the GE int.

then the related fcip interface :

interface fcip1

no shutdown

use-profile 1

peer-info ipaddr 100.100.100.2

"peer-info" here is the ip address of the GE interface of the remote MDS.

In your case, if the DWDM goes down meaning the remote GE becomes down, FCIP tunnel which is established on this interface goes down.

As long as you have the ip connectivity between

the mds switches, your fcip tunnel will remains up.

2) It is the same, if you use two separate cards as well.