This will be about already having nfsen/nfdump configured, and are looking to just make a flow profile to graph IPv6 traffic from your routers. If you are looking to get nfsen iniitially configured, definitely follow their instructions on their site.
Say you have an sFlow capable router like…picking one totally not at random…..a Brocade XMR or MLX(e), and you want some basic flow data, especially IPv6. Depending on how many routers you are going to collect flow data from, will determine how beefy of a machine you will need. I know that at $lastjob, it was a hefty CPU (and definitely more than 1), tons of RAM, and hardware RAID. Right now, I’m using dual quad-core Xeon, tons of RAM and a small hardware RAID, but this machine serves many purposes. Right now I’m also only polling 4 MLX routers.
Go ahead and access your nfsen website, and on the Profiles pulldown, select “New Profile …”. In the creation dialog, give the profile whatever title you like; I went with the generic title of “IPv6″. If you want to add it to a group or make one for it, do as you please. I left that alone so I’d Continue reading
This is a quick, high level rundown of Cisco's various fabric extender technologies and where each fits into the data center.
I was troubleshooting an OSPF area range summarization and came upon something I haven’t seen before called Passive Advertisement. There weren’t too many Cisco documents that explained it so I decided to post a really quick description explaining it in little detail and where you could see it . This could be useful for the CCIE troubleshooting section, when dealing with OSPF area summarization problems.
I will use R3 to demonstrate. This router is connected to area 0 and area 1 which makes it the only ABR connecting the two areas. R3 should be sending a summary route 18.104.22.168/16 for the two component routes 22.214.171.124/24 and 126.96.36.199/24. Looks pretty simple. To verify, I check the output of show ip ospf to make sure the area 0 range 188.8.131.52 255.255.0.0 command is configured:
R3#sh ip ospf
Routing Process "ospf 1" with ID 10.3.3.3
Start time: 00:00:23.404, Time elapsed: 00:01:06.080
Supports only single TOS(TOS0) routes
Supports opaque LSA
Supports Link-local Signaling (LLS)
Supports area transit capability
It is an area border and autonomous system boundary router
Redistributing External Routes from,
Router is Continue reading
What is IPv6 6to4 tunnel address? 2022::/16 or 2002::/16? How do you convert the IPv4 address into IPv6 6to4 tunnel address? Well there is the long way, which you should understand and then there is the easy way in case you need to configure it really quickly. I found this nice method where you can use the IPv6 General Prefix feature to automatically calculate the conversion. Originally this feature was used to create a variable for IPv6 network, the “general-prefix”, to easily change all IPv6 addresses in case reassignment of IP subnets.
Configuration is pretty simple. First make sure to have the 6to4 Tunnel’s source interface configured, in my example that’s Loopback0 184.108.40.206.
Rack1R1#sh ip int brief loop0 Interface IP-Address OK? Method Status Protocol Loopback0 220.127.116.11 YES manual up up
Then configure the IPv6 general-prefix for 6to4 type using loop0.
Rack1R1(config)#ipv6 general-prefix MY-GEN-PRE 6to4 loopback0 Rack1R1#sh ipv6 general-prefix IPv6 Prefix MY-GEN-PRE, acquired via 6to4 2002:9601:101::/48 Valid lifetime infinite, preferred lifetime infinite
The way you apply it on the tunnel is using regular ipv6 address command:
R1(config)#int tun1 R1(config-if)#ipv6 address ? WORD General prefix name X:X:X:X::X IPv6 link-local address X:X:X:X::X/ IPv6 prefix autoconfig Obtain address Continue reading