Address planning

Introduction Network-Level Design Considerations Factors affecting addressing scheme Recommended practices Case studies 6/4/20162

3 Network-Level Design Considerations 1.Using existing systems –translate the existing subnet numbers into IPv6 subnet Ids –translate the VLAN IDs into IPv6 subnet Ids 2.Redesign –allocate according to your need 3.Aggregation –Geographical Boundaries –Service Type –Organizational Boundaries

Factors affecting addressing scheme 1.Prefix aggregation 2.Network growth 3.ULA usage in large networks 4.Compact numbering of small sites 5.Consider assigning more than one /64 to a site 6.Host density (HD) value

Host Density Value PrefixTotal /56 blocks.94 HD value% Util blocks used gives HD value = Log128/ log 256 = 7/8 =.875 but the % utilisation is 50%. Log (number of assigned address blocks) HD = Log (maximum number of assignable address blocks) 6/4/20165

Recommended practices Separate address block for infrastructure /48 for individual site Aggregation for groups of sites Justification for prefixes shorter than /48

Recommended practices Assign a /48 for infrastructure( take PoP as a site) No subnets with prefixes longer than /64. Separate address block for router loop- back interfaces Assign a /64 per LAN / VLAN / subnet 6/4/20167

Recommended practices Organizations with multiple /48 allocations should consider enterprise-wise aggregation levels of /60 or larger blocks for the administration of enterprise policies for common functions IETF expects that you will assign a /64 for point-to-point links 6/4/20168

Recommended practices The enterprise network should receive a prefix sufficient to provide a /48 allocation for each site (office/campus/PoP) at which the company has employees or systems. All customers get one /48 unless they can show that they need more than 65k subnets 6/4/20169

Recommended practices Expect the registry to allocate a /32 and reserve one /32 If you need private addresses, generate a ULA prefix as defined in RFC 4193RFC /4/201610

ping pong packet amplification ( DOS attack) 6/4/201611

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Case Studies Address planning for an enterprise Address planning for a Service Provider 6/4/201614

Address planning for an Enterprise University of Southampton (UK) /48 address block allocated Dual stacked, no DHCPv hosts and users /56 to every faculty or school /56 for infrastructure /127 for loopback 6/4/201615

6/4/ sc Internet School 2 School 1 School 4 School 3 Data Centre L3 Distribution Switch L2 Access Switch L3 Core Switch L3 Data Centre Switch Firewall Router /48 /56 /56 for Infrastructure /127

Address planning for a Service Provider Roles to be fulfilled by a Service Provider –Local Internet Registry –Network Access Provider –Internet Service Provider Service provider Information –MPLS backbone –/32 address block 6/4/201617

Address planning for a Service Provider LIR Perspective of the SP ISP perspective of the SP N A provider perspective of SP 6/4/201618

LIR Perspective of the SP /48 for “common” customer Smaller prefix for “Big” customer Justify HD ratio Document all details support the reverse DNS mapping of the customer prefixes. 6/4/201619

ISP perspective of the SP Maximum aggregation Optimal flexibility for growth Multi-level network hierarchy Decoupling of provider network addressing and customer addressing 6/4/201620

N A provider perspective of SP Should handle new requirements from customer side. Reserve "buffer zone“ to allows the customer to grow in its addressing range without renumbering Allow multi-homing 6/4/201621

MPLS network architecture of SP 6/4/ MPLS Core Routers PE Router BB Router BB RAR AGR RAR Customer Networks

MPLS network architecture of SP BB-RAR: Broadband Remote access Router AGR: Aggregation Router RAR: Remote access Router PE Router : Provider Edge Router CE Router: Customer Edge Router ADSL connectivity at Customer end 6/4/201623

Addressing Plan /32 divided into 3 pools –/36 for “big” customers –/36 for direct customers on PE –/34 for BB customers /48 for Customers /36 for BB router /56 for RAR /36 for AG router 6/4/201624

Addressing Plan /56 from the "big" customers address pool for SP infrastructure /64 to every POP Loopback interfaces of routers from first /64 /126 for point to point link of customers from the /64 of the access router 6/4/201625

Thank You 6/4/201626