Nexus 7010

I’ve talked a little bit about NX-OS and the Nexus 7000 platform in previous posts.   In this post I want to share with you an interesting aspect of NX-OS I came across recently regarding VRFs (Virtual Routing and Forwarding) and originating default routes with EIGRP.   VRFs are not a new concept in the networking world and are extremely handy.   Basically, a VRF is a separate routing table instance on a particular router.   Those of you who have worked with Cisco IOS know that the “show ip route” command will display a list of all the routes the devices “knows” about.   If you had a VRF configured the “show ip route vrf “VRF-NAME’” command will display all the routes the device knows about for that particular routing table.   On the Nexus,   the concept is similar but working with VRFs are a tad different.

Configuring a VRF in NX-OS is pretty straight forward:

Nexus# conf t
Enter configuration commands, one per line.   End with CNTL/Z.
Nexus(config)# vrf context TEST
Nexus(config-vrf)#

We have now created the “TEST” VRF and are in “config-vrf” mode.   In this mode we have some options for further configuration.   One in particular is the ability to configure static routes:

Nexus(config-vrf)# ip ?
 auto-discard   Auto 0.0.0.0/0 discard route
 domain-list     Add additional domain names
 domain-name     Specify default domain name
 igmp                   IGMP global configuration commands
 mroute               Configure multicast RPF static route
 name-server     Specify nameserver address
 route                 Route information

Nexus(config-vrf)# ip route ?
 A.B.C.D           IP prefix in format i.i.i.i
 A.B.C.D/LEN   IP prefix and network mask length in format x.x.x.x/m

Nexus(config-vrf)# ip route 0.0.0.0/0 192.168.1.1
Nexus(config-vrf)#

At this point, we have configured a static default route within the TEST VRF.   So, now how do we advertise this route?   Well, I’m glad you asked:

Nexus(config)# router eigrp 10
Nexus(config-router)# vrf TEST
Nexus(config-router-vrf)# autonomous-system 15
Nexus(config-router-vrf)# address-family ipv4 unicast
Nexus(config-router-af)# default-information originate
Nexus(config-router-af)#

Pretty cool, huh?   At this point, any EIGRP neigbhors to this NX-OS router on the TEST VRF will recieve a default route so long as the appropriate interfaces have been configured for use with EIGRP (more on that another time).   I most definitely like this method than redistributing statics in IOS as it seems much easier to me.   Enjoy!

-Tim

Nexus 7010

The first production Nexus 7000s in the city of San Antonio.   I should have posted about this earlier I suppose, but it’s better late than never!   We installed these datacenter switches last Septemeber during a 12 hour maintenance window.   These two Cisco 7010s were replacements for two Cisco 6509 distribution switches.   I’m not going to give a full run down on what these switches can do but I will say a couple things I like about them.   They run NX-OS which has a very Unix CLI feel to it so I immediately felt right at home with the CLI.   These switches also have the ability to virtual port channel (vPC).     What that basically means is that you can set up a single port channel between a pair of Nexus switches and a host or other switch which is great from a redundancy stand point.   For the past several months, I’ve learned a lot about what the Nexus can and can’t do.   They are great pieces of network gear, but NX-OS has some maturing to do still.   Overall, they are pretty sweet.

-Tim