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IPv4 address allocation and the BGP routing table evolution
Abstract and Figures
The IP address consumption and the global routing table size are two of the vital parameters of the Internet growth. In this paper we quantitatively characterize the IPv4 address allocations made over the past six years and the global BGP routing table size changes during the same period of time. About 63,000 address blocks have been allocated since the beginning of the Internet, of which about 18,000 address blocks were allocated during our study period, from November 1997 to August 2004. Among these 18,000 allocations, 90% of them started being announced into the BGP routing table within 75 days after the allocation, while 8% of them has not been used up to now. Among all the address blocks that have ever been used, 45% of them were split into fragments smaller than the original allocated blocks; without these fragementations, the current BGP table would have been about half of its current size. Furthermore, we found that the evolution of BGP routing table consists of both the appearance of new prefixes and the disappearance of old prefixes. While the change of the BGP routing table size only reflects the combined results of the two processes, the dynamics of either process is much higher than that of the BGP table size. Finally, we classify routing prefixes into covering and covered ones, and examine their evolution separately. For the covered prefixes, which account for almost half of the BGP table size, we infer their practical motives such as multihoming, load balancing, and traffic engineering, etc., via a classification method.
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... Internet protocol (IP) is basically the primary protocol used by information technology for global communication. This protocol is utilized for data transmission from source to destination [2]. Internet protocol version 4 (IPv4) is the widely used internet protocol version in the world today [3]. ...
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... There are two forms of IP address: IPv4 and IPv6. For IPv4, the first 24-bit groups identify Network ID, and the remaining 8 bits represent Host ID [15]. For IPv6, the address is more standardized, which could be more easily solved. ...
The device detected from the public network usually associates with an IP as the unique identity generally. The problem is that many registrants of devices are always different from their true users, which make it difficult for operators to discover whether the IPs are used normally. The research on users of IPs plays an important role to help us for network security and protection. In this paper, we are seeking the users of devices and investigating why they are exposed to the public from five aspects: SSL certificates, protocol banners, address, topology and location. We presented FIUD: A Framework to Identify Users of Devices to extract users automatically. FIUD is based on Seed Extension so as to ensure both accuracy and coverage of user identification. We evaluated our methodology in laboratory and in the real-world. Compared with the mature results in the industry, the experiment shows that our methodology has achieved higher performances to discover the true users of IPs. At the same time, we did the network measurement in Beijing based on our methodology.
... The backbone routing table has been growing at an exponential rate, driven mainly by multi-homing and the rapid development of mobile communication (Meng et al. 2005). The fast increasing routing table incurs fast increasing FIB. ...
With the fast development of Internet, the size of routing table in the backbone router continues to grow rapidly. forwarding information base (FIB), which is derived from routing table, is stored in line-card to conduct routing lookup. Since the line-card’s memory is limited, it would be worthwhile to compress the FIB for consuming less storage. Therefore, various FIB compression algorithms have been proposed. However, there is no well-presented mathematical support for the feasibility of the FIB compression solution, nor any mathematical derivation to prove the correctness of these algorithms. To address these problems, we propose a universal mathematical method based on the Group theory. By defining a Group representing the longest prefix matching rule, the bound of the worst case of FIB compression solution can be figured out. Furthermore, in order to guarantee the ultimate correctness of FIB compression algorithms, routing table equation test is proposed and implemented to verify the equivalence of the two routing tables before and after compression by traversing the 32-bit IP address space.
Autonomous Systems (ASes) exchange reachability information between each other using BGP---the de-facto standard inter-AS routing protocol. While IPv4 (IPv6) routes more specific than /24 (/48) are commonly filtered (and hence not propagated), route collectors still observe many of them.
In this work, we take a closer look at those "hyper-specific" prefixes (HSPs). In particular, we analyze their prevalence, use cases, and whether operators use them intentionally or accidentally. While their total number increases over time, most HSPs can only be seen by route collector peers. Nonetheless, some HSPs can be seen constantly throughout an entire year and propagate widely. We find that most HSPs represent (internal) routes to peering infrastructure or are related to address block relocations or blackholing. While hundreds of operators intentionally add HSPs to well-known routing databases, we observe that many HSPs are possibly accidentally leaked routes.
The size of the global routing table has been growing at an alarming rate. With the exhaustion of IPv4 addresses and the gradual deployment of IPv6 networks, the growth rate will continue to accelerate in the future. Although modern high performance routers provide enough line-card memory, Internet Service Providers (ISPs) cannot afford to upgrade their routers as fast as the growth of global routing tables. In this paper, we propose an algorithm to calculate the generalized next hops with strict partial order (GSPO next hops) of a network prefix and use them for the aggregation of the Nexthop-Selectable Forwarding Information Base (NSFIB). Since the existing NSFIB aggregation algorithm may introduce path stretch, we also propose a weighted NSFIB aggregation algorithm to effectively control path stretch under a given upper limit of the FIB size. Experiment results show that our algorithm can shrink the FIB size by at most 97% under IPv4 networks, and at most 95% under IPv6 networks. Under a given upper limit of the FIB size, our algorithm can reduce the path stretch by at least 22%.
Grafnet, a Graph Neural-Network (GNN)-based scheme learns IP-address-to-port mapping, leading to forwarding table-less routers. GNNs allow mapping network-wide features like adjacencies and addresses to generate new representations. Grafnet converts network-wide IP addresses to a feature space using GNNs. GNNs extrapolate node adjacencies onto a feature matrix, whose output tells which address/subnet is connected to a node and port. To do so, we use a GNN in conjunction with an Artificial Neural Network (ANN), whose output transforms graph adjacencies to address-based adjacencies. We exploit the fact that IP addresses are present in contiguous groups (subnets) or ‘ranges’. Large range sizes imply a better likelihood of Grafnets’ approximation, though with
enough
learning Grafnet learns just about all network-wide IP addresses, irrespective of range sizes. Grafnet is evaluated as an SDN scheme on (1) 75-node US-core network and (2) 2000-node, 5 million IP address-based random WAN topology. Analytically, we show equivalence between Grafnet and a Feed-forward neural network implying exhaustiveness and correctness. The proposed Grafnet model is able to work as a direct address translator without the need for tables in the forwarding plane of a router. Engineering considerations to implement Grafnet are also discussed.
In addition to the ever growing host population, multiple other factors have contributed to the rapid growth of the global Internet routing table, such as policy routing, multi-homing, and traffic steering. In this paper we first sort the routing table entries into two broad classes, covering pre-fixes which represent IP address blocks that do not overlap, either partially or completely, with the address block repre-sented by any other entry in the routing table, and covered prefixes, commonly referred to as "holes", which represent sub-blocks of those address blocks that are already repre-sented by some shorter prefixes in the routing table. We then develop a classification methodology by identifying the dif-ferent ways each covered prefix is announced to the global routing system. We inferred the causes of each covered pre-fix class and identified possible motives for the fragmenta-tion of covering prefixes. Based on our analysis, we pro-vide an empirical model of the global routing table growth by taking into account all the major factors that have been identified in this study.
The Border Gateway Protocol (BGP) is an inter-Autonomous System
routing protocol. It is built on experience gained with EGP as
defined in RFC 904 [1] and EGP usage in the NSFNET Backbone as
described in RFC 1092 [2] and RFC 1093 [3].
The primary function of a BGP speaking system is to exchange network
reachability information with other BGP systems. This network
reachability information includes information on the list of
Autonomous Systems (ASs) that reachability information traverses.
This information is sufficient to construct a graph of AS
connectivity from which routing loops may be pruned and some policy
decisions at the AS level may be enforced.
The Internet continues along a path of seeming inexorable growth, at a rate which has, at a minimum, doubled in size each year. How big it needs to be to meet future demands remains an area of somewhat vague speculation. Of more direct interest in the question of whether the basic elements of the Internet can be extended to meet such levels of future demand, whatever they may be. To rephrase this question, are there inherent limitations in the technology of the Internet, or its architecture of deployment that may impact on the continued growth of the Internet to meet ever expanding levels of demand?
The sizes of the BGP routing tables have increased by an order of magnitude over the last six years. This dramatic growth of the routing table can decrease the packet forwarding speed and demand more router memory space. In this paper, we explore the extent that various factors contribute to the routing table size and characterize the growth of each contribution. We begin with measurement study using routing tables of Oregon Route Views server to determine the contributions of multi-homing, load balancing, address fragmentation, and failure to aggregate to routing table size. We find that the contribution of address fragmentation is the greatest and is three times that of multi-homing or load balancing. The contribution of failure to aggregate is the least. Although multi-homing and load balancing contribute less to routing table size than address fragmentation does, we observe that the contribution of multi-homing and that of load balancing grow faster than the routing table does and that the load balancing has surpassed multi-homing becoming the fastest growing contributor. Moreover, we find that both load balancing and multi-homing contribute to routing table growth by introducing more prefixes of length greater than 17 but less than 25, which is the fastest growing class of prefixes. Next, we compare the growth of the routing table to the expanding of IP addresses that can be routed and conclude that the growth of routable IP addresses is much slower than that of routing table size. Last, we demonstrate that our findings based on the view derived from the Oregon server are accurate through evaluation using additional 15 routing tables collected from different locations in the Internet.
The recent growth in the size of the routing table has led to an interest in quantitatively understanding both the causes (eg multihoming) as well as the effects (eg impact on router lookup implementations) of such routing table growth. In this paper, we describe a new model called ARAM that defines the structure of routing tables of any given size. Unlike simpler empirical models that work backwards from effects (eg current prefix length distributions), ARAM approximately models the causes of table growth (allocation by registries, assignment by ISPs, multihoming and load balancing). We show that ARAM models with high fidelity three abstract measures (prefix distribution, prefix depth, and number of nodes in the tree) of the shape of the prefix tree --- as validated against 20 snapshots of backbone routing tables from 1997 to the present. We then use ARAM for evaluating the scalability of IP lookup schemes, and studying the effects of multihoming and load balancing on their scaling behavior. Our results indicate that algorithmic solutions based on multibit tries will provide more prefixes per chip than TCAMs (as table sizes scale toward a million) unless TCAMs can be engineered to use 8 transistors per cell. By contrast, many of today's SRAM-based TCAMs use 14-16 transistors per cell.
This paper examines the possibility of generating realistic routing tables of arbitrary size along with realistic BGP updates of arbitrary frequencies via an automated tool deployable in a small-scale test lab. Such a tool provides the necessary foundations to study such questions as: the limits of BGP scalability, the reasons behind routing instability, and the extent to which routing instability influences the forwarding performance of a router.We find that the answer is affirmative. In this paper we identify important characteristics/metrics of routing tables and updates which provide the foundation of the proposed BGP workload model. Based on the insights of an extensive characterization of BGP traffic according to such metrics as prefix length distributions, fanout, amount of nesting of routing table prefixes, AS path length, number and times between BGP update bursts and number and times between BGP session resets, etc., we introduce our prototype tool, rtg. rtg realizes the workload model and is capable of generating realistic BGP traffic. Through its flexibility and parameterization rtg enables us to study the sensibilities of test systems in a repeatable and consistent manner while still providing the possibility of capturing the different characteristics from different vantage points in the network.
The Internet consists of rapidly increasing number of hosts interconnected by constantly evolving networks of links and routers. Interdomain routing in the Internet is coordinated by the Border Gateway Protocol (BGP). BGP allows each autonomous system (AS) to choose its own administrative policy in selecting routes and propagating reachability information to others. These routing policies are constrained by the contractual commercial agreements between administrative domains. For example, an AS sets its policy so that it does not provide transit services between its providers. Such policies imply that AS relationships are an important aspect of Internet structure. We propose an augmented AS graph representation that classifies AS relationships into customer-provider, peering, and sibling relationships. We classify the types of routes that can appear in BGP routing tables based on the relationships between the ASs in the path and present heuristic algorithms that infer AS relationships from BGP routing tables. The algorithms are tested on publicly available BGP routing tables. We verify our inference results with AT&T internal information on its relationship with neighboring ASS. As much as 99.1% of our inference results are confirmed by the AT&T internal information. We also verify our inferred sibling relationships with the information acquired from the WHOIS lookup service. More than half of our inferred sibling-to-sibling relationships are confirmed by the WHOIS lookup service. To the best of our knowledge, there has been no publicly available information about AS relationships and this is the first attempt in understanding and inferring AS relationships in the Internet. We show evidence that some routing table entries stem from router misconfigurations.
BGP routing table sizes have increased by an order of magnitude over the last six years. This dramatic growth can decrease packet forwarding speed and demand more router memory space. We explore the extent that various factors contribute to the routing table size and characterize the growth of each contribution. We begin with a measurement study using the routing tables of an Oregon route views server to determine the contributions of multi-homing, load balancing, address fragmentation, and failure-to-aggregate to routing table size. Address fragmentation makes the greatest contribution and it is three times those of multihoming or load balancing. The contribution of failure-to-aggregate is the least. Although multihoming and load balancing contribute less to routing table size than address fragmentation, we observe that their contributions grow faster than the routing table does and that load balancing has surpassed multihoming, becoming the fastest growing contributor. Moreover, we find that both load balancing and multihoming contribute to routing table growth by introducing more prefixes of length between 17 and 25, which are the fastest growing prefixes. Next, we examine the growth routable IP addresses, and conclude that their growth is much slower than that of routing table size. Lastly, we demonstrate that our findings based on views derived from the Oregon server are accurate through an evaluation using 15 additional routing tables collected from different locations in the Internet.
The Internet consists of rapidly increasing number of hosts
interconnected by constantly evolving networks of links and routers.
Interdomain routing in the Internet is coordinated by the Border Gateway
Protocol (BGP). The BGP allows each autonomous system (AS) to choose its
own administrative policy in selecting routes and propagating
reachability information to others. These routing policies are
constrained by the contractual commercial agreements between
administrative domains. For example, an AS sets its policy so that it
does not provide transit services between its providers. Such policies
imply that AS relationships are an important aspect of the Internet
structure. We propose an augmented AS graph representation that
classifies AS relationships into customer-provider, peering, and sibling
relationships. We classify the types of routes that can appear in BGP
routing tables based on the relationships between the ASs in the path
and present heuristic algorithms that infer AS relationships from BGP
routing tables. The algorithms are tested on publicly available BGP
routing tables. We verify our inference results with AT&T internal
information on its relationship with neighboring ASs. As much as 99.1%
of our inference results are confirmed by the AT&T internal
information. We also verify our inferred sibling relationships with the
information acquired from the WHOIS lookup service. More than half of
our inferred sibling-to-sibling relationships are confirmed by the WHOIS
lookup service. To the best of our knowledge, there has been no publicly
available information about AS relationships and this is the first
attempt in understanding and inferring AS relationships in the Internet.
We show evidence that some routing table entries stem from router
misconfigurations