Techstat

    What problem are we trying to solve? We want to prevent the rouge DHCP Server from assinging addresses out to our clients. Normally this would be your favorite wanna-be IT employee that brings his own Linksys router in the mix to fix the network 🙂 Of course it can also protect from malicious …

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The problem : What if we want to speak IPv6 but the whole path isn't IPv6?   Here is our topology let's begin.     IOSv1 and 2 are dual stacked, however the link between IOSv1 and IOSv2 is not IPv6. This link represents many routers. There's always a chance that they don't support IPv6 …

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Prefix-lists are typically used by router "features" to provide filtering. They "pass" permitted networks to a filtering feature which will actually do the filtering. They are used by distribute-lists, filter-lists, route-maps. Basics Some quick points which will guide you on understanding the basics. IP prefix list can match on sub netmask of route (ranges). They …

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Here is our topology...     R1 has a loopback of 1.1.1.1/32 R2 has 2.2.2.2/32 R3 has 3.3.3.3/32 R4 has 4.4.4.4/32 R4 has 9.9.9.9/32   R1 to R2 is 10.0.1.0/24 (area 1) R2 to R3 is 10.0.2.0/24 (area 0) R3 to R4 is 10.0.3.0/24 (area 2)   R3 which is our ABR, has been configured …

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Link between IOSV1 and IOSV2 : 192.168.1.0/24 Link between IOSV2 and IOSV3: 192.168.2.0/24 Situation: We are running OSPF in our network. IOSV1 is hypothetically connect to an ISP router. Our ISP does not form an OSPF neighborship with us. That means that IOSV2 and IOSV3 can only reach the networks inside the OSPF routing domain. …

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