Scaling the Internet with LISP

Transcription

1 Scaling the Internet with LISP Olivier Bonaventure Department of Computing Science and Engineering Université catholique de Louvain (UCL) Place Sainte-Barbe, 2, B-1348, Louvain-la-Neuve (Belgium) 1

2 Scaling the Internet with LISP Issues with the current Internet architecture Separating Identifiers from Locators Locator-Identifier Separation Protocol (LISP) 2

3 Issues with the current Internet architecture Interdomain routing scalability Growth of BGP routing tables Evolution-Internet-Architecture/2008/ 3 Source : O. Bonaventure,

4 Issues with the current Internet architecture Interdomain routing scalability Growth of BGP routing tables pre-cid fast growth Evolution-Internet-Architecture/2008/ 3 Source : O. Bonaventure,

5 Issues with the current Internet architecture Interdomain routing scalability Growth of BGP routing tables CID works well pre-cid fast growth Evolution-Internet-Architecture/2008/ 3 Source : O. Bonaventure,

6 Issues with the current Internet architecture Interdomain routing scalability Growth of BGP routing tables CID works well Growth is back pre-cid fast growth Evolution-Internet-Architecture/2008/ 3 Source : O. Bonaventure,

7 Issues with the current Internet architecture Interdomain routing scalability Growth of BGP routing tables Internet bubble CID works well Growth is back pre-cid fast growth Evolution-Internet-Architecture/2008/ 3 Source : O. Bonaventure,

8 Issues with the current Internet architecture Interdomain routing scalability Growth of BGP routing tables Internet bubble CID works well Growth is back again! Growth is back pre-cid fast growth Evolution-Internet-Architecture/2008/ 3 Source : O. Bonaventure,

9 easons for the BGP growth Distribution of prefixes versus length /8 /9 - /15 /16 /17 /18 /19 /20 /21 /22 /23 /24 /25 - /32 4

10 easons for the BGP growth Why so many small prefixes? Allocation of IP prefixes to sites Initial solution chosen by IANA FCFS for all qualifying sites few constraints on which sites qualify for an IP prefix Once allocated, the prefix is owned by the site forever Solution introduced by Is after CID Two types of prefixes Provider Independent prefixes Given by Is to qualifying sites (basically ISPs paying their membership dues to the I) Owned by the site forever and can be globally announced Provider Aggregatable prefixes Given by ISPs from their own address block to customers Customers are expected to return their prefix to its owner if they change from ISP 5

11 Why do site prefer PI prefixes? Main reasons PI Sites own their prefix for eternity and can change of provider whenever they want PA prefixes cause a provider lock-in syndrome Changing the IP prefix used by a site is difficult IP addresses and prefixes are manually written in configurations files for routers DNS servers Firewalls DHCP servers printers voice and video equipment... Finding all the places where IP addresses and prefixes have been configured is difficult and error-prone With some care, it is possible to prepare an IPv6 site to ease a subsequent IP prefix renumbering, but unfortunately most configurations are not prepared for such a renumbering event 6

12 easons for the BGP growth More are more network are internally fragmented Internet link is sometimes cheaper than normal link Client : AS /17 2 A Provider AS123 I can reach / / /18 B I can reach /16 Global Internet Provider AS789 7

13 easons for the BGP growth More are more network are internally fragmented Internet link is sometimes cheaper than normal link Client : AS I can reach /16 A I can reach /16 and / /17 2 Provider AS / /18 B I can reach /16 Global Internet Provider AS789 7

14 easons for the BGP growth More are more network are internally fragmented Internet link is sometimes cheaper than normal link Client : AS I can reach /16 A I can reach /16 and / /17 2 Provider AS / /18 B I can reach /16 Global Internet Provider AS789 7

15 easons for the BGP growth More are more network are internally fragmented Internet link is sometimes cheaper than normal link Client : AS I can reach / /17 A I can reach /16 and / /17 2 Provider AS / /18 B I can reach /16 Global Internet Provider AS789 7

16 easons for the BGP growth More are more network are internally fragmented Internet link is sometimes cheaper than normal link Client : AS /17 2 I can reach / /17 A Provider I can reach AS /18 I can reach /16 and / / /18 I can reach / /18 B I can reach /16 Global Internet Provider AS789 7

17 easons for the BGP growth More are more network are internally fragmented Internet link is sometimes cheaper than normal link Client : AS /17 2 I can reach / /17 A Provider I can reach AS /18 I can reach /16 and / /17 and / / /18 I can reach / /18 B I can reach /16 and /18 Global Internet Provider AS789 7

18 easons for the BGP growth easons for the BGP growth Multihoming /16 2 I can reach /16 Provider AS /16 Provider AS789 I can reach /16 Global Internet 8

19 easons for the BGP growth easons for the BGP growth Multihoming Client : AS /16 2 Provider AS123 I can reach / /16 Provider AS789 I can reach /16 Global Internet 8

20 easons for the BGP growth easons for the BGP growth Multihoming Client : AS / /16 2 Provider AS123 I can reach / /16 Provider AS789 I can reach /16 Global Internet 8

21 easons for the BGP growth easons for the BGP growth Multihoming Client : AS I can reach / /16 2 I can reach / /23 Provider AS /16 Provider AS789 I can reach /16 Global Internet 8

22 easons for the BGP growth easons for the BGP growth Multihoming Client : AS I can reach / /16 2 I can reach / /23 I can reach /23 Provider AS /16 Provider AS789 I can reach /16 Global Internet 8

23 easons for the BGP growth easons for the BGP growth Multihoming Client : AS I can reach / /16 2 I can reach / /23 I can reach /23 Provider AS /16 Provider AS789 I can reach /16 and /23 Global Internet 8

24 easons for the BGP growth easons for the BGP growth Multihoming Client : AS I can reach / /16 2 I can reach /16 and / /23 I can reach /23 Provider AS /16 Provider AS789 I can reach /16 and /23 Global Internet 8

25 easons for the BGP growth easons for the BGP growth Traffic engineering Client : AS / /16 2 Provider AS123 I can reach / /16 Provider AS789 I can reach /16 Internet 9

26 easons for the BGP growth easons for the BGP growth Traffic engineering Client : AS I can reach / /16 2 I can reach / /23 I can reach /24 Provider AS /16 I can reach /16 Provider AS789 Internet 9

27 easons for the BGP growth easons for the BGP growth Traffic engineering Client : AS I can reach / /16 2 I can reach /16 and / /23 I can reach /24 Provider AS /16 I can reach /16 and /24 Provider AS789 Internet 9

28 easons for the BGP growth easons for the BGP growth Traffic engineering Client : AS I can reach / /16 2 I can reach /16 and / /23 I can reach /24 Provider AS /16 I can reach /16 and /24 Provider AS789 Internet 9

29 easons for the BGP growth easons for the BGP growth Traffic engineering Client : AS I can reach / /16 2 I can reach /16 and / /23 I can reach /24 Provider AS /16 I can reach /16 and /24 Provider AS789 Internet 9

30 easons for the BGP growth easons for the BGP growth Traffic engineering Client : AS /23 1 I can reach /24 and / /16 Provider AS789 I can reach / /16 and /23 2 I can reach /16 Provider AS123 and /24 I can reach /16 and /24 Internet 9

31 easons for the BGP growth easons for the BGP growth Traffic engineering Client : AS /23 1 I can reach /24 and / /16 Provider AS789 I can reach / /16 and /23 2 I can reach /16 Provider AS123 and /24 and /23 I can reach /16 and /24 and /23 Internet 9

32 Interdomain routing security Interdomain routing security Only Best Current Practices from network operators prevent a customer network from using BGP to announce the prefix of someone else Misconfigurations (fat fingers) are frequent 10

33 Issues with the current Internet architecture Limited size of IPv4 addressing space Weʼve seen this problem before and NAT, CID and IPv6 have been proposed... Evolution-Internet-Architecture/2008/ 11 Source O. Bonaventure,

34 Issues with the current Internet architecture Limited size of IPv4 addressing space Weʼve seen this problem before and NAT, CID and IPv6 have been proposed... Evolution-Internet-Architecture/2008/ 11 Source O. Bonaventure,

35 Scaling the Internet with LISP Issues with the current Internet architecture Separating Identifiers from Locators Locator-Identifier Separation Protocol (LISP) 12

36 The complementary roles of IP addresses The IP addresses currently used by endhosts play two complementary roles Applic. Transport Network DataLink Applic. Transport Network DataLink 13

37 The complementary roles of IP addresses The IP addresses currently used by endhosts play two complementary roles Identifier role : the IP address identifies (with port) the endpoint of transport flows Applic. Transport Network DataLink Applic. Transport Network DataLink 13

38 The complementary roles of IP addresses The IP addresses currently used by endhosts play two complementary roles Identifier role : the IP address identifies (with port) the endpoint of transport flows Applic. Transport Network DataLink Applic. Transport Network DataLink 13

39 The complementary roles of IP addresses The IP addresses currently used by endhosts play two complementary roles Identifier role : the IP address identifies (with port) the endpoint of transport flows Locator role : the IP address indicates the paths used to reach the endhost these paths are updated by routing protocols after each topology change Applic. Transport Network DataLink Applic. Transport Network DataLink 13

40 The complementary roles of IP addresses The IP addresses currently used by endhosts play two complementary roles Identifier role : the IP address identifies (with port) the endpoint of transport flows Locator role : the IP address indicates the paths used to reach the endhost these paths are updated by routing protocols after each topology change Applic. Transport Network DataLink Applic. Transport Network DataLink 13

41 The complementary roles of IP addresses The IP addresses currently used by endhosts play two complementary roles Identifier role : the IP address identifies (with port) the endpoint of transport flows Locator role : the IP address indicates the paths used to reach the endhost these paths are updated by routing protocols after each topology change Applic. Transport Network DataLink Applic. Transport Network DataLink 13

42 The complementary roles of IP addresses The IP addresses currently used by endhosts play two complementary roles Identifier role : the IP address identifies (with port) the endpoint of transport flows Locator role : the IP address indicates the paths used to reach the endhost these paths are updated by routing protocols after each topology change Applic. Transport Network DataLink Applic. Transport Network DataLink 13

43 The complementary roles of IP addresses The IP addresses currently used by endhosts play two complementary roles Identifier role : the IP address identifies (with port) the endpoint of transport flows Locator role : the IP address indicates the paths used to reach the endhost these paths are updated by routing protocols after each topology change Applic. Transport Network DataLink Applic. Transport Network DataLink 13

44 Existing identifiers Loopback addresses are already used as identifiers, but only on routers / / / /

45 Existing identifiers Loopback addresses are already used as identifiers, but only on routers / / / / In contrast with endhost addresses and normal addresses on routers, loopback addresses are not tied to a particular physical interface a loopback address is always reachable provided that one of the routerʼs interfaces remains up loopback addresses are often used as identifiers this is only possible because the loopback addresses are directly advertised by the routing protocols 14

46 Principle of the Host-based solutions Transport layer IP routing sublayer 15

47 Principle of the Host-based solutions Transport layer Identifier : Id.A IP routing sublayer 15

48 Principle of the Host-based solutions Transport layer Identifier : Id.A IP routing sublayer Locators { Green.1, ed.2} 15

49 Principle of the Host-based solutions Transport layer Identifier : Id.A IP routing sublayer Locators { Green.1, ed.2} 15

50 Principle of the Host-based solutions Transport layer Identifier : Id.A Specific sublayer IP routing sublayer Locators { Green.1, ed.2} oles Translates the packets so that Transport layer always sees only the host identifier IP outing sublayer sees only locators Manages the set of locators Securely switches from one locator to another upon move or after link failure each host maintains some state 15

51 Principles of the Network-based solutions Transport layer IP routing sublayer 16

52 Principles of the Network-based solutions Hostʼs IP stack unchanged Each host has one stable IP address used as identifier not globally routed Transport layer Identifier : IPA IP routing sublayer 16

53 Principles of the Network-based solutions Hostʼs IP stack unchanged Each host has one stable IP address used as identifier not globally routed Transport layer Identifier : IPA IP routing sublayer Locators { IPGreen.A, IPed.A} 16

54 Principles of the Network-based solutions Hostʼs IP stack unchanged Each host has one stable IP address used as identifier not globally routed Transport layer Identifier : IPA IP routing sublayer Each edge router owns globally routed addresses used as locators Mapping mechanism is used to find locator associated to one identifier Packets from hosts are modified before being sent on Internet Locators { IPGreen.A, IPed.A} 16

55 Scaling the Internet with LISP Issues with the current Internet architecture Separating Identifiers from Locators Locator-Identifier Separation Protocol (LISP) 17

56 The Locator Identifier Separation Protocol Principles Define a router-based solution where current IP addresses are separated in two different spaces EndPoint Identifiers (EID) are used to identify endhosts. They are non-globally routable. Hosts in a given site are expected to use EIDs in the same prefix. outing Locators (LOC) are globally routable and are attach to routers A mapping mechanism allows to map an EndPoint Identifier onto the outing Locator(s) of the site router(s) outers encapsulate the packets received from hosts before sending them towards the destination LOC 18

57 LISP : design goals Main design goals Minimize required changes to Internet equire no hardware no software changes to endsystems (hosts) Be incrementally deployable equire no router hardware changes Minimize router software changes Avoid or minimize packet loss when EID-to-LOC mappings need to be performed 19

58 LISP : simple example AS /8 0100: DD:: Provider1 - AS /8 Provider2 - AS / : FF:: : FE::

59 LISP : simple example AS /8 0100: DD:: Provider1 - AS /8 Provider2 - AS / : FF::1234 S: 0100: FF::1234 D: 0100: FE:: : FE::

60 LISP : simple example AS /8 0100: DD:: Provider1 - AS /8 Provider2 - AS / S: 0100: FF::1234 D: 0100: DD:: : FF:: : FE::

61 LISP : simple example Mapping System AS /8 Mapping request Where is 0100: DD: : DD::8765 Provider1 - AS /8 Provider2 - AS / S: 0100: FF::1234 D: 0100: DD:: : FF:: : FE::

62 LISP : simple example Mapping reply for 0100: DD::8765 LOC Mapping System LOC AS /8 Mapping request Where is 0100: DD: : DD::8765 Provider1 - AS /8 Provider2 - AS / S: 0100: FF::1234 D: 0100: DD:: : FF:: : FE::

63 LISP : simple example AS /8 Provider1 - AS /8 Outer header S: D: Inner S: 0100: FF::1234 D: 0100: DD:: Provider2 - AS /8 0100: DD:: S: 0100: FF::1234 D: 0100: DD:: : FF:: : FE::

64 LISP : Terminology AS / : DD::8765 Provider1 - AS /8 Provider2 - AS / : FF:: : FE::

65 LISP : Terminology AS / : DD::8765 Provider1 - AS /8 Provider2 - AS / Ingress Tunnel outer (IT) : A router which accepts a packet containing a single IP header. The router maps 1 the destination address of the 2packet to an LOC and prepends a LISP header before forwarding the encapsulated packet. 0100: FF:: : FE::

66 LISP : Terminology AS /8 Provider1 - AS / Provider2 - AS /8 0100: DD::8765 Egress Tunnel outer (ET) : A router which accepts a LISP encapsulated packet. The router strips the LISP header and forwards the packet based on the next header Ingress Tunnel outer (IT) : A router which accepts a packet containing a single IP header. The router maps 1 the destination address of the 2packet to an LOC and prepends a LISP header before forwarding the encapsulated packet. 0100: FF:: : FE::

67 LISP : Terminology EID-to-LOC Database : a globally distributed database that contains all know EID-prefix to LOC mappings. AS /8 Provider1 - AS / Provider2 - AS /8 0100: DD::8765 Egress Tunnel outer (ET) : A router which accepts a LISP encapsulated packet. The router strips the LISP header and forwards the packet based on the next header Ingress Tunnel outer (IT) : A router which accepts a packet containing a single IP header. The router maps 1 the destination address of the 2packet to an LOC and prepends a LISP header before forwarding the encapsulated packet. 0100: FF:: : FE::

68 LISP data packet format 32 bits Ver IHL DS Total length Outer header Identification Flags Offset TTL Protocol Checksum Source outing Locator Destination outing Locator 22

69 LISP data packet format 32 bits Ver IHL DS Total length Outer header Identification Flags Offset TTL Protocol Checksum Source outing Locator Destination outing Locator UDP Src port : xxxx Dst port : 4341 UDP Length UDP checksum 22

70 LISP data packet format 32 bits Ver IHL DS Total length Outer header Identification Flags Offset TTL Protocol Checksum UDP Source outing Locator Destination outing Locator Src port : xxxx Dst port : 4341 UDP Length UDP checksum Source port should be random Destination port set to

71 LISP data packet format 32 bits Ver IHL DS Total length Outer header Identification Flags Offset TTL Protocol Checksum UDP LISP header Src port : xxxx Dst port : 4341 UDP Length UDP checksum Locator reach bits S E es. Source outing Locator Destination outing Locator Nonce Source port should be random Destination port set to

72 LISP data packet format 32 bits Ver IHL DS Total length Outer header Identification Flags Offset TTL Protocol Checksum UDP LISP header Src port : xxxx Dst port : 4341 UDP Length UDP checksum Locator reach bits S E es. Source outing Locator Destination outing Locator Nonce Source port should be random Destination port set to 4341 Used to indicate which xt are up. 22

73 LISP data packet format 32 bits Ver IHL DS Total length Outer header Identification Flags Offset TTL Protocol Checksum UDP LISP header Src port : xxxx Dst port : 4341 UDP Length UDP checksum Locator reach bits S E es. Source outing Locator Destination outing Locator Nonce Source port should be random Destination port set to 4341 Used to indicate which xt are up. Used to validate some control messages 22

74 LISP data packet format 32 bits Ver IHL DS Total length Outer header Identification Flags Offset TTL Protocol Checksum S: Solicit Map equest E: Echo equest UDP LISP header Src port : xxxx Dst port : 4341 UDP Length S E es. Source outing Locator Destination outing Locator UDP checksum Locator reach bits Nonce Source port should be random Destination port set to 4341 Used to indicate which xt are up. Used to validate some control messages 22

75 LISP data packet format 32 bits Ver IHL DS Total length Outer header Identification Flags Offset TTL Protocol Checksum S: Solicit Map equest E: Echo equest UDP LISP header Inner packet Src port : xxxx Dst port : 4341 UDP Length S E es. Ver Tclass Source outing Locator Destination outing Locator Payload Length UDP checksum Locator reach bits Nonce Flow Label NxtHdr Hop Limit Source EndPoint Identifier (128 bits) Source port should be random Destination port set to 4341 Used to indicate which xt are up. Used to validate some control messages 22

76 LISP Mapping Possible models for the mapping mechanism Push model LISP ET routers receive from a protocol to be designed the mapping tables that they need to use to map EIDs onto LOCs Pull model LISP ET routers refresh their mapping table by querying the mapping mechanism each time they receive a packet whose mapping is unknown Hybrid models Push is used to place popular or important mappings on LISP ET routers and they query for the less important mappings 23

77 NED A Not-so-novel EID to LOC Database The only proposed push model Composed of 4 parts a network database format; a change distribution format; a database retrieval/bootstrapping method; a change distribution method Principles An authority computes the mapping database based on the stored registrations The database signed by the authority is stored on servers IT poll regularly the database servers to update their own mapping database 24

78 LISP mapping messages Sent over UDP destination port 4342 source port random Map-request message 1 Flags eserved ec.# Nonce Source-AFI IT-AFI Source-EID Address Originating IT LOC es. masklen AFI EID-prefix Mapping protocol data 25

79 LISP mapping messages Sent over UDP destination port 4342 source port random Map-request message Number of records in map-request 1 Flags eserved ec.# Nonce Source-AFI IT-AFI Source-EID Address Originating IT LOC es. masklen AFI EID-prefix Mapping protocol data 25

80 LISP mapping messages Sent over UDP destination port 4342 source port random Map-request message 1 Flags eserved ec.# Number of records in map-request andom in request, copied in reply Nonce Source-AFI IT-AFI Source-EID Address Originating IT LOC es. masklen AFI EID-prefix Mapping protocol data 25

81 LISP mapping messages Sent over UDP destination port 4342 source port random Map-request message 1 Flags eserved ec.# Source-AFI Nonce IT-AFI Number of records in map-request andom in request, copied in reply LOC of the IT sending the map-request message Source-EID Address Originating IT LOC es. masklen AFI EID-prefix Mapping protocol data 25

82 LISP mapping messages Sent over UDP destination port 4342 source port random Map-request message 1 Flags eserved ec.# Source-AFI Nonce IT-AFI Number of records in map-request andom in request, copied in reply LOC of the IT sending the map-request message Source-EID Address Originating IT LOC es. masklen AFI EID-prefix Mapping protocol data mask length of EID prefix 25

83 LISP mapping messages Sent over UDP destination port 4342 source port random Map-request message 1 Flags eserved ec.# Source-AFI Nonce IT-AFI Number of records in map-request andom in request, copied in reply LOC of the IT sending the map-request message Source-EID Address Originating IT LOC es. masklen AFI EID-prefix Mapping protocol data AFI of the requested mapping mask length of EID prefix 25

84 LISP mapping messages Sent over UDP destination port 4342 source port random Map-request message 1 Flags eserved ec.# Source-AFI Nonce IT-AFI Number of records in map-request andom in request, copied in reply LOC of the IT sending the map-request message Source-EID Address Originating IT LOC es. masklen AFI EID-prefix Mapping protocol data EID prefix for which the mapping is requested AFI of the requested mapping mask length of EID prefix 25

85 LISP mapping messages Map-reply message format sent over UDP E C O D 2 eserved ec.# Nonce ecord TTL Loc. # masklen A eserved eserved EID - AFI EID prefix Prio Weight MPrio MWeight Unused flags Loc-AFI Locator Mapping protocol data 26

86 LISP mapping messages Copied from Mapequest Map-reply message format sent over UDP 2 eserved ec.# Nonce E C O D ecord TTL Loc. # masklen A eserved eserved EID - AFI EID prefix Prio Weight MPrio MWeight Unused flags Loc-AFI Locator Mapping protocol data 26

87 LISP mapping messages Map-reply message format sent over UDP Number of records in map-reply Copied from Mapequest 2 eserved ec.# Nonce E C O D ecord TTL Loc. # masklen A eserved eserved EID - AFI EID prefix Prio Weight MPrio MWeight Unused flags Loc-AFI Locator Mapping protocol data 26

88 LISP mapping messages Map-reply message format sent over UDP Number of records in map-reply Copied from Mapequest 2 eserved ec.# Nonce Lifetime of record ( min. ) 0: remove from cache 0xffffffff: receiver decides E C O D ecord TTL Loc. # masklen A eserved eserved EID - AFI EID prefix Prio Weight MPrio MWeight Unused flags Loc-AFI Locator Mapping protocol data 26

89 LISP mapping messages Map-reply message format sent over UDP Number of records in map-reply Copied from Mapequest E C O D 2 eserved ec.# Nonce ecord TTL Loc. # masklen A eserved eserved EID - AFI EID prefix Prio Weight MPrio MWeight Unused flags Loc-AFI Locator Mapping protocol data Lifetime of record ( min. ) 0: remove from cache 0xffffffff: receiver decides Authoritative or not 26

90 LISP mapping messages Map-reply message format sent over UDP Number of records in map-reply Copied from Mapequest E C O D 2 eserved ec.# Nonce ecord TTL Loc. # masklen A eserved eserved EID - AFI EID prefix Prio Weight MPrio MWeight Unused flags Loc-AFI Locator Mapping protocol data Lifetime of record ( min. ) 0: remove from cache 0xffffffff: receiver decides Authoritative or not Priority : LOCs with lower priority are preferred. If several have same priority, load balance among them Weight : percentage of traffic to this LOC when load balancing is active 26

91 LISP mapping messages Map-reply message format sent over UDP Number of records in map-reply Copied from Mapequest 2 eserved ec.# Nonce ecord TTL Lifetime of record ( min. ) 0: remove from cache 0xffffffff: receiver decides Authoritative or not Is record is reachable from responderʼs viewpoint? E C O D Loc. # masklen A eserved eserved EID - AFI EID prefix Prio Weight MPrio MWeight Unused flags Loc-AFI Locator Mapping protocol data Priority : LOCs with lower priority are preferred. If several have same priority, load balance among them Weight : percentage of traffic to this LOC when load balancing is active 26

92 LISP mapping messages Map-reply message format sent over UDP Number of records in map-reply Copied from Mapequest 2 eserved ec.# Nonce ecord TTL Lifetime of record ( min. ) 0: remove from cache 0xffffffff: receiver decides Authoritative or not Is record is reachable from responderʼs viewpoint? E C O D Loc. # masklen A eserved eserved EID - AFI EID prefix Prio Weight MPrio MWeight Unused flags Loc-AFI Locator Mapping protocol data Priority : LOCs with lower priority are preferred. If several have same priority, load balance among them Weight : percentage of traffic to this LOC when load balancing is active Used for Multicast 26

93 How to control incoming traffic? LISP site can control incoming traffic with Weight and Priority A 0100: DD::8765/48 A primary, C backup Mapping for 0100:DD::/48 LOC , prio=1, weight=100 LOC , prio=99, weight=100 C