UDLR Unidirectional Link Routing overview and examples

Transcription

1 UDLR Unidirectional Link Routing overview and examples ourse Number Presentation_ID 1999, isco Systems, Inc. 1

2 UDLR Tunnels UDLR simulates a bi-directional link by tunneling over the return path Supports both IP unicast and multicast Supports all IP routing protocols (including IS-IS for IP) Supports address resolution via RP and NHRP 2

3 asic UDLR Tunnel Operation unidirectional tunnel Internet unidirectional link Traffic from the downstream network ( or ) destined for s unidirectional interface will traverse the unidirectional tunnel. Packets are encapsulated by in a GRE IP packet and forwarded to upstream router. decapsulates the GRE packet, and places the original packet on the input queue belonging to s unidirectional link. local net ccess filters limit traffic on the upstream and downstream tunnel interfaces IP, RP, NHRP, and LNS (for IS-IS IP routing) are supported. Upstream router s routing protocol must never advertise the tunnel subnet over the unidirectional link interface - this will cause a recursive tunnel in downstream routers. 3

4 Mechanisms Three mechanisms are available to implement unidirectional links: UDLR-IGMP IGMP-Mroute Proxy UDLR-Tunnel 4

5 UDLR-IGMP Detailed examples 5

6 What is UDLR-IGMP? scalable mechanism to support IGMP joins over a unidirectional link. Upstream router queries for members with a unicast source address different than the satellite net. Downstream router forwards IGMP reports with TTL > 1 to the unicast querier address. Upstream router echoes IGMP report back out one-way link to suppress other downstream reports. 6

7 UDLR-IGMP Join 1) sends queries using a unicast address other than the one on the unidirectional link (udl) 2) and learn querier Multicast source in Group G 5) gets report for G, associates with UDLR subnet, and puts it on forward list 6) forwards s report for G on UDLR link Internet unidirectional link Internet 7) learns is reporter for G 8) suppresses report for G 4) knows no reporter for G, forwards IGMP report to s non-udl unicast address 9) Receiver reports for Group G 3) Receiver reports for Group G 7

8 UDLR-IGMP Leave 4) receives Leave for G from and forwards on UDLR link, but doesn t delete interface from forward list Multicast source for Group G 8) receives report from for G Internet unidirectional link Internet 5) receives leave for group G, knows that is no longer the reporter 7) forwards report for group G to 2) sends GS-Query and determines no more members. 3) sends leave for group G to querier 6) Receiver reports for Group G 1) Receiver leaves Group G 8

9 UDLR-IGMP example Router interface ethernet 0 ip address ip pim dense-mode interface ethernet 1 ip address ip pim dense-mode ip igmp unidirectional link interface ethernet 2 ip address Internet Router interface ethernet 0 ip address ip pim dense-mode ip igmp unidirectional link interface ethernet 1 ip address ip pim sparse-dense-mode ip igmp helper-address udl ethernet 0 interface ethernet 2 ip address

10 IGMP-Mroute Mroute proxy Detailed examples 10

11 IGMP-Mroute Mroute Proxy UDLR-IGMP does not support the distribution of multicast groups beyond links directly connected to the downstream router. The IGMP-Mroute proxy overcomes this by forwarding an IGMP report to an interface for each group in the multicast routing table. In conjunction with UDLR-IGMP, IGMP reports are forwarded to an upstream router for each group in the mroute table. To populate the unidirectional downlink router s mroute table, other downstream routers enable PIM sparse mode and use the unidirectional downlink router as the rendezvous point. 11

12 UDLR-IGMP with Mroute Proxy Operation unidirectional tunnel 5) Router creates and maintains a forwarding entry on the unidirectional link. Its behavior is the same as with UDLR-IGMP Internet LN unidirectional link 3) Router receives the pim join and adds a forwarding entry for Group G on LN 4) Router periodically checks its mroute table, and forwards an IGMP report for each group for which it is the reporter local net 2) Router sends PIM join hop by hop to RP (router ) 1) User joins group G 12

13 UDLR-IGMP with Mroute Proxy Internet Router ip pim rrp-address access-list 5 permit interface ethernet 0 ip address ip pim sparse-mode interface ethernet 1 ip address ip pim sparse-mode local net Router interface ethernet 0 ip address ip pim dense-mode Interface ethernet 1 ip address ip pim dense-mode ip igmp unidirectional link Interface ethernet 2 ip address Router ip pim rp-address access-list 5 permit interface loopback 0 ip address ip pim dense-mode ip igmp helper-address udl ethernet 0 ip igmp proxy-service interface ethernet 0 ip address ip pim dense-mode ip igmp unidirectional link interface ethernet 1 ip address ip pim sparse-mode ip igmp mroute-proxy loopback 0 interface ethernet 2 ip address

14 UDLR Tunnel Detailed examples 14

15 UDLR Tunnel configuration Router interface loopback 0 ip address interface tunnel 0 ip address tunnel source loopback 0 tunnel mode gre multipoint tunnel key 5 tunnel udlr receive-only ethernet 1 interface ethernet 0 ip address interface ethernet 1 ip address interface ethernet 2 ip address Internet local net Router access-list 101 permit ospf any any access-list 101 permit icmp any any interface loopback 0 ip address interface tunnel 0 ip address ip access-group out 101 tunnel source loopback 0 tunnel destination tunnel key 5 tunnel udlr send-only ethernet 0 tunnel udlr address-resolution interface ethernet 0 ip address no keepalive interface ethernet 1 ip address interface ethernet 2 ip address

16 UDLR Tunnel with NHRP Internet Router Unidirectional link interface ethernet 1 ip address ip nhrp network-id 5 ip nhrp server-only local net Router Unidirectional link interface ethernet 0 ip address ip nhrp network-id 5 ip nhrp nhs

17 UDLR Tunnel with RIP Router router rip version 2 network Ethernet 1 local net Router router rip version 2 passive-interface tunnel 0 network distribute-list 10 out ethernet 1 access-list 10 deny any Router router rip version 2 passive-interface tunnel 0 network

18 UDLR Tunnel with EIGRP Router router eigrp 200 network Ethernet Router router eigrp 200 passive-interface tunnel 0 network distribute-list 10 out ethernet 1 access-list 10 deny any Router router eigrp 200 passive-interface tunnel 0 network local net 18

19 UDLR Tunnel with IGP Router router bgp 1 no synchronization network mask network mask neighbor remote-as 1 neighbor remote-as 1 neighbor route-reflector-client Ethernet local net Router router bgp 1 no synchronization network mask network mask network mask network mask neighbor remote-as 1 neighbor remote-as 1 neighbor distribute-list 10 out access-list 10 deny any Router router bgp 1 no synchronization network mask network mask network mask neighbor remote-as 1 neighbor remote-as 1 19

20 UDLR Tunnel with EGP Router router bgp 3 no synchronization network mask network mask neighbor remote-as 1 neighbor remote-as Ethernet local net Router router bgp 1 no synchronization network mask network mask network mask network mask neighbor remote-as 2 neighbor remote-as 3 neighbor distribute-list 10 out access-list 10 deny any Router router bgp 2 no synchronization network mask network mask network mask neighbor remote-as 1 neighbor remote-as 3 20

21 UDLR Tunnel with OSPF Router router ospf 200 network area 0 network area Ethernet Router interface tunnel 0 ip address router ospf 200 passive-interface tunnel 0 Don t advertise the tunnel subnet over the udl area 0 range not-advertise network area 0 network area 0 network area 0 network area 1 local net Router router ospf 200 passive-interface tunnel 0 network area 1 network area 1 network area 1 21

22 UDLR Tunnel with ISIS Router interface ethernet 0 ip address ip router isis 2 interface ethernet 1 ip address ip router isis 1 router isis 1 network c.00 is-type level-1 router isis 2 network c Ethernet local net Router interface tunnel 0 ip address ip router isis 2 interface ethernet 0 ip address ip router isis 2 interface ethernet 1 ip address ip router isis 1 interface ethernet 2 ip address ip router isis 2 router isis 1 network a.00 is-type level-1 router isis 2 passive-interface tunnel 0 network a.00 Router interface tunnel 0 ip address interface ethernet 0 ip address ip router isis 1 interface ethernet 1 ip address ip router isis 1 interface ethernet 2 ip address router isis 1 network b.00 is-type level-1 ip default-route

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