Posts tagged OSPF

OSPF Lab #1 Walkthrough

May 13th

Posted by Colby in Labs

1 comment

This is the walkthrough for OSPF Lab #1.

Here’s the topology:

Click here for the initial configs

Here is task one:
1. Configure R1′s s0/0.102 interface and R2′s s0/0.201 interface in area 12, this area should not receive any Type 5 LSAs. Configure R1′s s0/0.103 interface and R3′s s0/0.301 interface in area 13, R1 should only receive a default route from R3, no other OSPF routes should be in R1′s RIB (from R3). Do not use network statements to accomplish this task.

Config:

R1(config)#interface Serial0/0.102 point-to-point
R1(config-subif)#ip ospf 100 area 12
R1(config-subif)#
R1(config-subif)#interface Serial0/0.103 point-to-point
R1(config-subif)#ip ospf 100 area 13
R1(config-subif)#
R1(config-subif)#router ospf 100
R1(config-router)#area 12 stub
R1(config-router)#area 13 stub
 
R2(config)#interface Serial0/0.201 point-to-point
R2(config-subif)#ip ospf 100 area 12
R2(config-subif)#
R2(config-subif)#router ospf 100
R2(config-router)#area 12 stub
 
R3(config)#interface Serial0/0.301 point-to-point
R3(config-subif)#ip ospf 100 area 13
R3(config-subif)#
R3(config-subif)#router ospf 100
R3(config-router)#area 13 stub no-summary

Here we configure OSPF 100 under the routers’ interfaces (avoiding network statements). Then we configure R1 and R2′s link/area as a stub. Last we configure R1 and R3′s link/area as a totally stubby area, preventing R3 from sending anything buy a default route to R1.

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OSPF Lab #1 Tasks

May 12th

Posted by Colby in Labs

9 comments

This is the first OSPF post I’ll be doing for CCIE lab preparation. Sorry guys, I’ve been slacking with updates. Today I’m posting the tasks, then tomorrow or the day after I’ll post the walkthrough. If any of you work on this before the walkthrough, leave a comment.

Here’s the topology:

Click here for the initial configs

Here are the tasks:
1. Configure R1′s s0/0.102 interface and R2′s s0/0.201 interface in area 12, this area should not receive any Type 5 LSAs. Configure R1′s s0/0.103 interface and R3′s s0/0.301 interface in area 13, R1 should only receive a default route from R3, no other OSPF routes should be in R1′s RIB (from R3). Do not use network statements to accomplish this task.

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Simple IPv6 Tutorial

Apr 20th

Posted by Colby in Tutorials

9 comments

Today we’ll configure a basic IPv6 network. I’m not a big fan of IPv6. I’ve never used it in the real world, so it’s hard for me to keep it in my head, but I’ve been studying the hell out of it for the Written, so here goes.

We have a simple topology, only three routers. We will be running OSFPv3 on our serial links and loopbacks. Here’s our topology:


(Click image for fullsize)

First we’ll configure our IPv6 addresses:

R1:
R1(config)#ipv6 unicast-routing
R1(config)#int s0/0
R1(config-if)#ip add 10.1.12.1 255.255.255.0
R1(config-if)#ipv6 add 10:1:1:12::1/64
R1(config-if)#no shut
 
R2:
R2(config)#ipv6 unicast-routing
R2(config)# int s0/0
R2(config-if)#ip add 10.1.12.2 255.255.255.0
R2(config-if)#ipv6 add 10:1:1:12::2/64
R2(config-if)#no shut
R2(config-if)#exit
R2(config)#int s0/1
R2(config-if)#ip add 10.1.23.2 255.255.255.0
R2(config-if)#ipv6 add 10:1:1:23::2/64
R2(config-if)#no shut
 
R3:
R3(config)#ipv6 unicast-routing
R3(config-if)#int s0/1
R3(config-if)#ip add 10.1.23.3 255.255.255.0
R3(config-if)#ipv6 add 10:1:1:23::3/64

The first thing we do on each router is enable IPv6 routing. Then we give the interface an IPv4 address and finally an IPv6 address.

Let’s verify connectivity from R2:

Serial0/0 is up, line protocol is up
  IPv6 is enabled, link-local address is FE80::C001:71FF:FE12:0
  Global unicast address(es):
    10:1:1:12::2, subnet is 10:1:1:12::/64
  Joined group address(es):
    FF02::1
    FF02::2
    FF02::1:FF00:2
    FF02::1:FF12:0
  MTU is 1500 bytes
  ICMP error messages limited to one every 100 milliseconds
  ICMP redirects are enabled
  ND DAD is enabled, number of DAD attempts: 1
  ND reachable time is 30000 milliseconds
  Hosts use stateless autoconfig for addresses.
Serial0/1 is administratively down, line protocol is down
  IPv6 is enabled, link-local address is FE80::C001:71FF:FE12:0 [TEN]
  Global unicast address(es):
    10:1:1:23::2, subnet is 10:1:1:23::/64 [TEN]
  Joined group address(es):
    FF02::1
    FF02::2
    FF02::1:FF00:2
    FF02::1:FF12:0
  MTU is 1500 bytes
  ICMP error messages limited to one every 100 milliseconds
  ICMP redirects are enabled
  ND DAD is enabled, number of DAD attempts: 1
  ND reachable time is 30000 milliseconds
  Hosts use stateless autoconfig for addresses.
 
R2#sh ipv int b
Serial0/0                  [up/up]
    FE80::C001:71FF:FE12:0
    10:1:1:12::2
Serial0/1                  [up/up]
    FE80::C001:71FF:FE12:0
    10:1:1:23::2
 
R2#ping  10:1:1:12::1
Sending 5, 100-byte ICMP Echos to 10:1:1:12::1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 0/2/4 ms
 
R2#ping  10:1:1:23::3
Sending 5, 100-byte ICMP Echos to 10:1:1:23::3, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 0/3/12 ms

We have connectivity between interfaces on the same subnet.

Now we’ll configure our loopbacks and OSPFv3:

R1:
R1(config-if)#int lo0
R1(config-if)#ipv6 add 1:1:1::1/64
R1(config-if)#ipv6 ospf 20 area 0
R1(config-if)#int s0/0
R1(config-if)#ipv6 ospf 20 area 0
 
R2:
R2(config)#int lo0
R2(config-if)#ipv6 add 2:2:2::2/64
R2(config-if)#ipv6 ospf 20 area 0
R2(config-if)#int s0/0
R2(config-if)#ipv6 ospf 20 area 0
R2(config-if)#int s0/1
R2(config-if)#ipv6 ospf 20 area 0
 
R3:
R3(config)#int lo0
R3(config-if)#ipv6 add 3:3:3::3/64
R3(config-if)#ipv6 ospf 20 area 0
R3(config-if)#int s0/1
R3(config-if)#ipv6 ospf 20 area 0

With v6 we enable OSPF directly under the interface on which it runs.

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Narbik Day 2, Part 1

Apr 13th

Posted by Colby in Personal

10 comments

Day 2 is nearly over. It’s been full of OSPF. Lots of lecture and labbing. Narbik has so much in his brain, it’s really unbelievable. Everyone knows that OSPF is very deep, but after today I’m speechless. I’ve made some tables and a diagram (from Narbik’s drawing on the whiteboard) with some of the information I want to save. Here is table of OSPF LSA Types:

(click image for fullsize)

It tells you which type of router sends them, what they look like in the RIB, what commands we can use to see them and some other things.

Here is the table of OSPF Network Types:

(click image for fullsize)

Also filled with good info.

Here is the diagram I made from his drawing on the board:

(click image for fullsize)

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Troubleshooting Lab #6

Apr 7th

Posted by Colby in Troubleshooting Labs

9 comments

First lab with our new topology. I’m excited! This should be an easy one. When functioning correctly, Customer “a” connects to AS 6500 using MPLS VPNs and running OSPF with the provider between sites. Site 2 (CE2a) has internet access through a physical connection to AS 6500s global RIB, it also has a GRE tunnel to PE1 which connects to the MPLS VPN. Customer “b” has a similar configuration. Customer “b” is using EIGRP. Both customers have a single “internet” circuit which is reachable from only one site, all internet traffic from the other site will go over the WAN first.

The issue today is users in VLAN 40 are having issues accessing the internet (87.3.85.1), determine why.

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