Archive for the ‘config’ tag
A few hours ago, the last of the IPv4 addresses were allocated by IANA. Now's the time to learn more about IPv6! Yesterday, I posted about EIGRP for IPv6, so I think I'll continue the trend by introducing OSPFv3, which is the IPv6 implementation of OSPF. As always, I'm using Cisco routers here. Just as yesterday, this is just a guide to the absolutely basics; if you want to do some funky OSPF magic, you won't find it here – perhaps in time, though.
As with all IPv6 routing protocols, the first thing we need to do is enable IPv6 unicast routing.
OSPFv3 also has the same router ID problem as EIGRP for IPv6 has, so we have to sort that out. You can set the router ID either through a loopback interface with an IPv4 address on it or you can set it manually. I'll just do it manually for now. Let's use OSPF process ID 100.
Router(config)#ipv6 router ospf 100
Just like in OSPFv2 and in EIGRP for IPv6, we add interfaces to the routing protocol instead of using network statements; those don't exist in OSPFv3. Let's assume you already have IPv6 addresses on interface f0/0 and you want that network in area 0.
Router(config-if)#ipv6 ospf 100 area 0
You can see that it's really easy to add interfaces to different areas as well.
Checking Our Work
Just like we did yesterday, let's check to make sure the right interfaces are participating in the routing protocol. We can do this with the show ipv6 ospf interface brief command.
Router#show ipv6 ospf interface brief Interface PID Area Intf ID Cost State Nbrs F/C Fa0/1 100 0 5 10 BDR 1/1 Fa0/0 100 2 4 10 DR 0/0
You can see that we've got two FastEthernet interfaces in two different OSPF areas. You can even see the state and neighbor count in the output.
That looks good, so let's check to see if we have any neighbors. Of course, we already saw that we have one off of f0/1 from the output above, but just humor me and run show ipv6 ospf neighbors.
Router#sh ipv6 ospf neighbor Neighbor ID Pri State Dead Time Interface ID Interface 192.0.2.2 1 FULL/DR 00:00:31 5 FastEthernet0/1
That looks good to me. The other guy is a DR and is full adjacent with our router. Cool.
One last command shows us the routing table. Can you guess what that command is without looking at the book? Very good, class. It's show ipv6 route.
Router#sh ipv6 route IPv6 Routing Table - 6 entries ... C FC00:1::/64 [0/0] via ::, FastEthernet0/1 L FC00:1::1/128 [0/0] via ::, FastEthernet0/1 C FC00:2::/64 [0/0] via ::, FastEthernet0/0 L FC00:2::1/128 [0/0] via ::, FastEthernet0/0 O FC00:3::/64 [110/20] via FE80::C001:1CFF:FED0:1, FastEthernet0/1 OI FC00:4::/64 [110/30] via FE80::C001:1CFF:FED0:1, FastEthernet0/1 L FF00::/8 [0/0] via ::, Null0
Isn't that fancy? We seem to have both an area router (the O route) and an inter-area route (the OI route). We are ready for the big time now!
tunnel broker recommendations questions my way.
I'm not going to go all out like Jeremy over at Packetlife.net has, but I'm going to start to discuss a few IPv6 topics. In time (like in September when APNIC runs out of IPv4 addresses), I'm sure I'll ramp up the IPv6 talk, but let's start easy and get EIGRP for IPv6 up and running.
There are quite a few differences between EIGRP for IPv6 (yes, that's an official name) and the IPv4 version. First of all, all IPv6 routing is disabled by default on a Cisco router, so, if you're doing any routing in IPv6, you'll want to enable it or risk smashing your head into the desk trying to figure out what's going on.
Next, let's get to configuring EIGRP for IPv6. By default,
IPv6 routing protocols (all of them?) are EIGRP for IPv6 is shut down like Ethernet interfaces, so we'll have to enable it first.
Router(config)#ipv6 router eigrp 100
There's also the issue of the router ID. In IPv4, EIGRP has an method to figure out its router ID, and EIGRP for IPv6 uses that same method. The problem is that the router ID is still a 32-bit number, but there aren't any 32-bit address on the router if you're pure IPv6. A dilemma, eh? There are two way to get around this, though. First, you can set a loopback interface with an IPv4 address so that EIGRP will have an address to use.
Router(config-if)#ip address 192.0.2.1 255.255.255.255
You can also statically assign a router ID to EIGRP for IPv6.
Router(config)#ipv6 router eigrp 100
Either method gets the same result. Of course, you should be careful that all routers have a unique ID.
So now we need to add some network statements, right? Actually, there are no network statements in EIGRP for IPv6. The interfaces themselves are where you configure the networks to be included in the routing protocol. It's kinda like the way you can use the interfaces to configure OSPFv2.
Router(config-if)#ipv6 eigrp 100
Of course, we're assuming you already have an IPv6 address on f0/0.
Checking our Work
Let's check to see if everything is working the way we think it should be. First of all, let's make sure all our interfaces are participating as expected with the show ipv6 eigrp interface command.
Router#sh ipv6 eigrp interfaces IPv6-EIGRP interfaces for process 100 Xmit Queue Mean Pacing Time Multicast Pending Interface Peers Un/Reliable SRTT Un/Reliable Flow Timer Routes Fa0/0 0 0/0 0 0/1 0 0 Fa0/1 1 0/0 23 0/2 50 0
This output looks a lot like the IPv6 version, and we can see both f0/0 and 0/1 are participating. That looks right, so let's check for EIGRP neighbors with the show ipv6 eigrp neighbor. I've got another router off of f0/1, so we should see a neighbor adjacency.
Router#sh ipv6 eigrp neighbors IPv6-EIGRP neighbors for process 100 H Address Interface Hold Uptime SRTT RTO Q Seq (sec) (ms) Cnt Num 0 Link-local address: Fa0/1 13 00:02:40 23 200 0 11 FE80::C001:14FF:FEB0:1
What the heck is FE80::C001:14FF:FEB0:1??!?!?! That's not a network we configured! That's actually the link-local address of the other router off of f0/1. Perhaps I'll discuss IPv6 addressing some day (when I have a firmer grasp on it), but, for now, I'll just say that it's a special address for hosts to talk to one another on a local network.
Finally, let's check for routes.
R1#show ipv6 route eigrp IPv6 Routing Table - 6 entries ... D 2002::/64 [90/307200] via FE80::C001:14FF:FEB0:1, FastEthernet0/1
Just like in IPv4, EIGRP for IPv6 routes show up with the route code of "D". It's looks like we have one route to the 2002::/64 network. Everything seems to be working!
There are obviously a lot of more features and functions to EIGRP for IPv6, but this should get you started in your studies. I'm sure I'll expound as time and my CCIE studies progress.
6to4 tunnels questions my way.
I was exploring commands on the ASA a while back and discovered that you can run commands on the standby unit from the active. Read the rest of this entry »