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Posts tagged GNS3
Added Dynamips/GNS3 Page
Dec 2nd
It will be nicer to have a page dedicated solely to .net files. You can now see them all from the link in the header. Or click here.
There aren’t many files yet, but I promise more will come.
BGP Backdoor Lab
Nov 12th
In this article we’ll be going over the BGP Backdoor feature. This is used in cases where two systems are connected via an IGP, but also receiving routes to the same system through BGP. I stumbled across this feature while checking out one of the labs on Darren’s Blog. The only way I could think of to complete one of his criteria was changing the Administrative Distance of either BGP or the IGP. That is essentially what this feature does, but on a route-by-route basis instead of changing the AD of an entire protocol. I asked Darren if that was the only solution and he pointed me to “BGP Backdoor”. As usual, I will be including my Dynagen/GNS3 .net file at the end of this post. Here is our topology:
Let’s go through the config:
R1
hostname R1 ! interface Serial0/0 ip address 10.1.1.1 255.255.255.0 ! interface Serial0/1 ip address 10.1.3.1 255.255.255.0 ! router bgp 65000 no synchronization bgp log-neighbor-changes neighbor 10.1.1.2 remote-as 65525 neighbor 10.1.3.2 remote-as 65535 no auto-summary |
ODR Lab
Oct 31st
In this article we’ll do a short ODR (On Demand Routing) lab. ODR is a simple routing protocol targeted at hub and spoke topologies, it uses CDP to propagate routing updates. This is one of the technologies that might be on the CCIE exams. I will be including my Dynagen/GNS3 .net file at the end of this post. Here is our topology:
Let’s go through the config:
R1
hostname R1 ! interface Loopback0 ip address 1.1.1.1 255.255.255.255 ! interface Serial0/0 ip address 10.1.0.1 255.255.255.252 ! interface Serial0/1 ip address 10.1.1.1 255.255.255.252 ! interface Serial0/2 ip address 10.1.2.1 255.255.255.252 ! router odr |
We configure the hostname and our Loppback and Serial interfaces. The important command here is “router odr”, this turns ODR on. This command is ONLY run on the hub.
R2:
hostname R2 ! interface Loopback0 ip address 2.2.2.2 255.255.255.255 ! interface Serial0/0 ip address 10.1.0.2 255.255.255.252 |
R3:
hostname R3 ! interface Loopback0 ip address 3.3.3.3 255.255.255.255 ! interface Serial0/0 ip address 10.1.1.2 255.255.255.252 |
R4:
hostname R4 interface Loopback0 ip address 4.4.4.4 255.255.255.255 ! interface Serial0/0 ip address 10.1.2.2 255.255.255.252 |
We now have our hostnames and interfaces configured on R1, R2 and R3. Notice we DO NOT use the “router odr” command on the spokes.
Surprisingly, that is all there is to it! Let’s verify our config:
Basic AToM Lab
Oct 14th
In this article we’ll go over a simple AToM (Any Transport over MPLS) configuration. I’ve been studying MPLS a lot lately and this is my first time playing with AToM and it’s very cool stuff. This article could be useful for anyone studying MPLS and/or CCIP/CCIE topics, or just someone who is interested in learning new things. I will be including my Dynagen/GNS3 .net file with this. Here is our topology:
Let’s go through the config:
P Router:
hostname P ! mpls label protocol ldp mpls ldp router-id lo0 force ! interface Loopback0 ip address 1.1.1.1 255.255.255.255 ! interface FastEthernet1/0 ip address 10.1.1.1 255.255.255.252 duplex auto speed auto mpls ip ! interface FastEthernet1/1 ip address 10.1.2.1 255.255.255.252 duplex auto speed auto mpls ip ! router ospf 100 router-id 1.1.1.1 log-adjacency-changes network 1.1.1.1 0.0.0.0 area 0 network 10.1.1.0 0.0.0.3 area 0 network 10.1.2.0 0.0.0.3 area 0 |
Here we’ve set the hostname, configured the MPLS label protocol (note: LDP is the default on new IOSes), we set a loopback interface that will be our RID for MPLS and OSPF. We also configured our connections to the PE routers and brought up OSPF as our IGP.
PE1 Router:
hostname PE1 ! mpls label protocol ldp mpls ldp router-id lo0 force ! pseudowire-class one encapsulation mpls ! interface Loopback0 ip address 2.2.2.2 255.255.255.255 ! interface FastEthernet1/0 ip address 10.1.1.2 255.255.255.252 duplex auto speed auto mpls ip ! interface Serial2/0 no ip address xconnect 3.3.3.3 100 pw-class one ! router ospf 100 router-id 2.2.2.2 log-adjacency-changes network 2.2.2.2 0.0.0.0 area 0 network 10.1.1.0 0.0.0.3 area 0 |
PE2 Router:
hostname PE2 ! mpls label protocol ldp mpls ldp router-id lo0 force ! pseudowire-class one encapsulation mpls ! interface Loopback0 ip address 3.3.3.3 255.255.255.255 ! interface FastEthernet1/0 ip address 10.1.2.2 255.255.255.252 duplex auto speed auto mpls ip ! interface Serial2/0 no ip address xconnect 2.2.2.2 100 pw-class one ! router ospf 100 router-id 3.3.3.3 log-adjacency-changes network 2.2.2.2 0.0.0.0 area 0 network 10.1.2.0 0.0.0.3 area 0 |
Great MPLS and BGP Lab
Oct 12th
I got this over at Networking-Forum.com, a member named Fred created it, he was even kind enough to provide the Visio diagram, IP scheme spreadsheet and, most importantly, the .net file for Dynagen/GNS3. I spent a lot of my Saturday working on this beast. I thought I should share it here as it is great practice for MPLS VPNs and BGP along with some OSPF, NAT, IPSEC and GRE exposure.
(click image for fullsize)
Internet
* The two Internet routers should serve as transit AS’s. No other routers should permit transit traffic.
* Internet sites (modeled by loopbacks) should be accessible by all lan IP’s.
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